TRADITIONAL MARRIAGE PATTERN IN IFITEDUNU IN DUNUKOFIA LOCAL GOVERNMENT AREA, ANAMBRA STATE.

DEVELOPMENT OF A BMS FOR A BASIC HOME INVERTER SYSTEM BY EDEH EMMANUEL SOMTOO 2016/235557 ENETE CHIBUIKE JAPHET 2016/240727 NWOKEDI SAMUEL CHIEDOZIE 2016/231376 DEPARTMENT OF ELECTRONIC ENGINEERING FACULTY OF ENGINEERING UNIVERSITY OF NIGERIA NSUKKA NOVEMEBER, 2022 TITLE PAGE DEVELOPMENT OF A BMS FOR A BASIC HOME INVERTER SYSTEM A PROJECT PROPOSAL REPORT PRESENTED TO THE DEPARTMENT OF ELECTRONIC ENGINEERING, UNIVERSITY OF NIGERIA, NSUKKA IN PARTIAL FULFILMENT OF THE REUIREMENTS FOR THE AWARD OF BACHELOR OF ENGINEERING (B.ENG) DEGREE IN ELECTRONIC ENGINEERING BY EDEH EMMANUEL SOMTOO 2016/235557 ENETE CHIBUIKE JAPHET 2016/240727 NWOKEDI SAMUEL CHIEDOZIE 2016/231376 SUPERVISOR: ENGR. THANKGOD OZUE NOVEMBER, 2022 Dedication This work is dedicated to the Almighty God for his goodness and mercy upon our lives. Acknowledgement My gratitude goes to our parents and guardian for their love and financial support. Special thanks to our supervisor Engr. Thankgod Ozue, who has put in the best of his time and intellectual resources to see that this work is brought to a successful completion. We also thank our lecturers and the entire Department of Electronic Engineering, University of Nigeria Nsukka, we could not have made it this far without the training and knowledge impacted on us by you. Abstract The use of green energy such as solar is becoming increasingly important in today’s world to curb the negative effect on climate change resulting from fossil fuels , and energy produced form solar panels are stored in batteries. It is very important to make sure that the battery being used is as reliable as the fossil fuel. Thus, the design of the battery management control system plays a significant role on battery life preservation and performance improvement of solar systems. This project battery management control system (BMCS) is a hardware/software solution which checks the correct operation of batteries, it simply charges the batteries when they are empty, and discharges them when necessary as a result performs many tasks including the measurement of system voltage, current and temperature, the cells’ state of charge (SOC), state of health (SOH), controlling and monitoring the charge / discharge characteristics and cell balancing to avoid fast degradation. A 40V solar panel, Lithium-Ion batteries,ACS758current sensor, Arduino Nano microcontroller, Relay switches, Arduino UNO Wi-Fi module, LCD, amongst other supporting components are used in the design and implementation of a circuit to achieve this project. TABLE OF CONTENTS Title page i Approval page ii Dedication iii Acknowledgement iv Abstract v Table of Contents vi CHAPTER ONE: INTRODUCTION 1 1.0 INTRODUCTION 1 1.1 BACKGROUND OF STUDY 2 1.2 PROBLEM STATEMENT 3 1.3 AIMS AND OBJECTIVES OF THE BMS 3 1.4 SCOPE AND LIMITATON 4 1.5 JUSTIFICATION 5 1.6 SIGNIFICANCE OF THE PROJECT 6 CHAPTER TWO: LITERATURE REVIEW 7 2.0 LITERATURE REVIEW 7 2.1 A GENERAL BATTERY MANAGEMENT CONTROL SYSTEM 9 2.2 HOW DOES A BATTERY MANAGEMENT SYSTEM WORK? 11 2.3 THE FUNTIONS OF THE BMCS 12 2.4 COMMUNICATIONS 15 2.5 THE INTERNET OF THINGS (IoT) 17 2.8 RELATED WORKS 18 2.9 SUMMARY 21 CHAPTER THREE: THE BATTERY MANAGEMENT SYSTEM 22 3.0 THE BATTERY MANAGEMENT SYSTEM 22 3.2 STATE OF CHARGE (SOC) CALCULATION 24 3.4 HARDWARE COMPONENTS 25 3.5 SOFTWARE COMPONENT 36 3.6 SOFTWARE FLOWCHART 36 3.7 CIRCUIT DIAGRAM 37 3.8 SYSTEM FLOWCHART 39 3.9 SYSTEM BLOCK DIAGRAM 40 CHAPTER 4 DESIGN 41 4.0 DESIGN 41 4.1 DESIGN OF THE CIRCUIT 41 4.2 TESTING 44 4.4 COST OF PRODUCTION 45 4.6 SYSTEM SECIFICATIONS 46 CHAPTER 5 CONCLUSION AND RECOMMENDATIONS 47 5.1 CONCLUSION 47 5.2 FUTURE WORK AND RECOMMENDATIONS 47 REFERENCE 48 APPENDIX A 51 CHAPTER ONE INTRODUCTION 1.0 INTRODUCTION In power generation industry, reducing the greenhouse gas emission is of great importance, by using solar energy, the emission of this gas is reduced. However, battery is a central component of the solar step which provides power when the energy producer cannotand as such should be properly managed for maximum efficiency. The main aim of Battery Management Control System (BMCS) is to ensure that the battery is always charged. To achieve this, a detailed simulation of the traction system in the solar energy setup and a detailed battery model is required to design the BMCS. Battery Management Control System (BMCS) of battery monitoring gives inputs to the protection devices so that the monitoring circuits could generate alarms and even disconnect the battery from the load or charger if any of the parameters exceed the values set by the safety zone. It also provides us with the accurate information on when to replace a damaged battery. The definition of BMCS can be based on the tasks it performs and can be defined according to the following [1]: • It should ensure that the energy of the battery is optimized to power the product. • It should ensure that the risk of damaging the battery is minimal. • It should monitor and control the charging and discharging process of the battery. In order to deliver greater performance, the Battery Management Control System (BMCS) must be improved. The battery monitoring system (BMS) is a component of the battery management system (BMCS) that is required to monitor the operational system, performance, and battery life, as well as the charge and discharge process. The battery monitoring system is made up of equipment that measure factors such battery voltage, current, and temperature. These values can be used to calculate the battery's state of charge (SOC) and state of health (SOH). [2, 3] 1.1 BACKGROUND OF STUDY The demand for the renewable energy has been provided for since the invention of solar panels and other affiliate sources such as the wind energy, tidal energy etc.However, the technique to effectively manage the stored energy is still a problem that demands a lasting solution. The solar panels need inverters which will convert the direct current from the solar panels into alternating current that the home appliances use. Battery storage system (BSS) is a backup energy system that will deliver its stored energy when the main energy source does not produce energy. Battery Management Control System (BMCS) is needed to monitor battery state and ensure the safety of operation. BMCS is typically equipped with an electronic switch that disconnects the battery from the charger or load under critical conditions that can lead to dangerous reactions. A battery protection unit (BPU) prevents possible damages to the battery cells and the failure of the battery, such critical conditions include: • Over charging • High and low temperature • Over-discharging • Over-current • Reverse polarity. 1.2 PROBLEM STATEMENT The importance of the solar energy system and its management components is critical since they will help to extend the system's lifespan. The panel, battery, and inverter are the components of solar energy systems. A good battery management system will have a significant impact on the battery's efficiency and lifespan. Battery damage has recently been reported as a result of inadequate management. When the sun, which is the primary source of energy, goes out, the electricity supply is also disrupted. We hope to develop a solution to successfully manage the battery in this project so that the issues listed above can be avoided or reduced to a minimum. We also wanted to incorporate an internet of things (IoT) system that will allow us to collect data from the battery management system and send it to the cloud for analysis. This will assist us in determining when the battery is defective and needs to be replaced. 1.3 AIMS AND OBJECTIVES OF THE BMS The battery management system is critical and has the objectives of the battery’s safe operation, overall performance and longevity. The battery management system also has the primary function of the protecting the battery cell of the inverter from damaged caused by being overcharged or over-discharged. This study is aimed at achieving some the aforementioned characteristic functions of modern BMS. These functions are: i. The BMCS observes the state of charge of charge (SoC). ii. Monitors the voltage and current. iii. Monitors the operational safety condition by checking for loose connections and internal shorts. 1.4 SCOPE AND LIMITATION Control charging of the battery, with practically no overcharging, to ensure a long cycle life of the battery, Monitor the discharge of the battery to prevent damage inflicted on the battery by interrupting the discharge current when the battery is empty, keep track of the battery’s SoC and use the determined value to control charging and discharging of the battery and signal the value to the user of the portable device through the cloud, and power the load with a minimum supply voltage, irrespective of the battery voltage, using DC/DC conversion to achieve a longer run time of the portable device. The scope of this project with the design and construction has to do with following: • Battery • DDC digital controller • Sensors • Actuators • Programming tools • TCP/IP- transfer control protocols/internet protocol • Graphics or user interface This project in general enables data from the battery management system to be gotten from the battery and analyzed, and displayed on the graphic user interface in form of charts/graphs the DOD, SOH, Voltage and Current. LIMITATIONS The limitation of the battery management system we designed is that it can only be used for a lead acid battery and not for a lithium ion battery 1.5 JUSTIFICATION Science and technology have advanced over time, with new innovations in a variety of sectors and greater adjustments to current technology, all aimed at improving the effectiveness and durability of equipment while also reaching a high degree of downsizing and optimal cost thereby balancing the fluctuating features of renewable energies. This idea arose from our interest in electronic control and the search for a way to curtail the excesses of battery damage as a result of poor maintenance and management. It is of useful importance to the energy storage unit in the following ways; • Providing ancillary services such as frequency and voltage stability • Maintaining a stable energy supply • Increasing the penetration of renewable energy. • It ensures that the battery is protected and any operation out of its safety limit is prevented. • Decreases damage done to the environment. • Controls voltage fluctuations or imbalance in voltage conditions. • Manages the battery optimization via cell balancing that improves the life of the battery in the long run. 1.6 SIGNIFICANCE OF THE PROJECT Homes and small scale industry have a crucial need for constant electricity; it’s unfortunate that the maintenance of constant electricity is a dilemma in Nigeria. So having a fully functional solar energy system will reduce the cost spent on electricity bills. To achieve a fullyfunctional solar energy system, the battery has to be properly managed. The BMCS developed in this project will help to protect the battery from over charging, deep discharging, over loading, under temperature, over temperature and short circuit. The BMCS can communicate with other devices, allowing you to examine the battery's condition and date history online. Protocols such as BLE, CAN, and CAM are used to enable communication. Minimum and maximum voltages, maximum current limitations, open cell voltage for state of charge, weak cell thresholds, charge controller status, thermal management status, and other data are commonly monitored. CHAPTER TWO LITERATURE REVIEW 2.0 LITERATURE REVIEW Batteries have been around for a long time, earthen containers that served as galvanic cells dating from 250 BC have been found in Baghdad. These containers were filled with iron and copper electrodes, together with an organic acidic solution. This yielded a cell capable of supplying 250 mA at a voltage of 0.25 V for approximately 200 hours, and these cells were used to gild silver[4]. Two names are closely associated with the development of batteries and the related science of electrochemistry. These names are Luigi Galvani and AlessandroVolta [5]. Galvani performed an experiment in 1790, in which he suspended a frog from an iron hook. With a copper probe he measured electric pulses, which he believed originated in contractions of the muscles of the frog’s legs. Volta attributed these contractions to the current flowing between the iron and copper metals. To prove that current could flow between two metals with an electrolyte in between, he built a ‘pile’ consisting of alternating silver and zinc plates interleaved with paper or cloth, which was soaked with an electrolyte. Hence, Volta was the first person in modern times to have built an actual battery. He patented this structure in 1800. In1834, Michael Faraday derived the laws of electrochemistry based on Volta’s work.This established a connection between chemical and electrical energy.On the basis of Volta’s work, other scientists also developed batteries of various designs. A recurring problem with these batteries was gas formation at the electrodes. This limited the available capacity, because the energy used to form the gas could not be recovered. Leclanché found the most successful solution to this problem in 1866[6]. He used manganese dioxide for the positive electrode, mixed with carbon to improve conductivity. This mixture was fixed around a graphite plate, which served as a current collector. He used zinc for the negative electrode, while ammonium chloride served as the electrolyte and he achieved an opencircuit voltage of 1.5 V with this battery. It could supply a medium current and had a good shelf life. Others later improved the so-called Leclanché cell. The present-day non-rechargeable batteries based on this principle, zinc-carbon or zinc-manganese dioxide (ZnMnO2) batteries, still dominate the household battery market on a worldwide basis [7]. Their performance improved by 700% between 1920 and 1990. The investigation of the behaviour of various metals in various electrolytes, in particular diluted sulphuric acid, by Gaston Planté was another important event in the development of batteries in 1859 [8]. He constructed batteries as a sandwich of thin layers of lead, separated by sheets of coarse cloth in a cylindrical container filled with diluted sulphuric acid. The thin lead layers were connected as two separate electrodes he then introduced a voltage difference between the two lead electrodes, which charged the battery. By alternating this charge process with a subsequent discharge step, he eventually managed to form a positive electrode that consisted of lead dioxide and a negative electrode consisting of finely distributed lead. Repeated cycling could increase the thickness of these layers. After the formation of the active layers, which eventually took some 24 hours, the charge voltage of the lead/lead-dioxide couple rose to 2.7 V. In order to prevent breakdown of the lead plates, Planté later used thicker plates, which led to quite heavy and bulky batteries that were used mainly for stationary applications. One of the first applications of a battery of this type was in a house-lighting installation with a dynamo, which served as charger, built by Henri Tudor in 1882 [9]. The time-consuming formation process was later greatly simplified by Camille Faure in France and Charles Brush in the USA in 1881 [10]. An important difference with respect to the Leclanché cell was that the cells constructed by Planté were rechargeable. The so-called lead acid batteries are still widely used nowadays, for example as car batteries for engine starting and vehicle lighting, but they are used very little in consumer electronics. The advances in the development of portable electronic systems have had a significant effect on the development of new types of batteries. However, only fairly little progress has been made in improving battery characteristics such as energy density, shelf life and reliability in comparison to the advances made in electronic circuits [11]. While existing types of batteries are continuously being improved, new types keep appearing. The introduction of the nickel-metalhydride (NiMH) battery in 1990 and the lithium-ion (Li-ion) battery in 1991 were of a great importance for portable consumer products. Research at Royal Philips Electronics played an important role in the development of NiMH batteries [12]. Apart from the continuous need for higher energy densities, environmental concerns have also boosted the development of these new types of batteries. 2.1 A GENERAL BATTERY MANAGEMENT CONTROL SYSTEM In more general terms, the charger of BMCS can be called a Power Module (PM). This PM is capable of charging the battery, but can also power the load directly. A general BMCS consists of a PM, a battery, a DC/DC converter and a load. The intelligence in the BMS is included in monitor and control functions, the monitor functions involve the measurement of, for example, battery voltage, and charger status or load activity. The control functions act on the charging and discharging of the battery on the basis of these measured variables.Implementation of these monitor and control functions should ensure optimum use of the battery and should prevent the risk of any damage being inflicted on the battery. The degree of sophistication of the BMCS will depend on the functionality of the monitor and control functions. In general, the higher this functionality, the better care will be taken of the battery and the longer its life will be. The functionality depends on several aspects: • The cost of the portable product: In general, the additional cost of a BMCS should be kept low relative to the cost of the portable product. Hence, the functionality of the monitor and control functions of a relatively cheap product will generally be relatively low. As a consequence, the BMCS will be relatively simple. • The features of the portable product: This is closely related to the product’s cost. A high- end product will have more features than a low-end product. For example, a high-end shaver with a ‘Minutes Left’ indication needs more BMCS intelligence than a low-end shaver with no signaling at all. • The type of battery: Some types of batteries need more care than others. • The type of portable product: In some products, a battery will be charged and discharged more often than in others. For example, a cellular phone might be charged every day, whereas a shaver is charged only once every two or three weeks. The number of times a battery can be charged and discharged before it wears out, together with the average time between subsequent charge cycles, determines the lifetime of a battery in a device. So it is more important for this number to be high in a cellular phone than in a shaver. This can be achieved by making the BMCS more intelligent. Therefore, a more sophisticated BMCS is more important in a cellular phone than in a shaver. The intelligence needed for the BMCS can be divided between the various parts. This partitioning of intelligenceis an important aspect in designing a BMS. The main determining parameter in this respect is cost. Dedicated battery management ICs can implement intelligence. Measured variable and parameter values and control commands are communicated between the parts of the BMS via a communication channel. This channel can be anything from a single wire that controls a Pulse- Width Modulation (PWM) switch to a bus that is controlled by a dedicated protocol. The structure of a general BMS is shown in Figure 2.0. The partitioning of intelligence is symbolized by placing a ‘Monitor and Control’ block in every system part. The BMS shown in Figure 2.0 also controls a Battery Status Display. An example is a single Light-Emitting Diode (LED) that indicates the ‘battery low’ status. It can also be a string of LEDs indicating the battery’s State-of-Charge (SoC) or a Liquid-Crystal Display (LCD) that indicates the battery status, including theSOC and the battery condition. Figure 2.0: A general Battery Management Control System (BMCS) 2.2 HOW DOES A BATTERY MANAGEMENT SYSTEM WORK? The battery management system monitors the individual cells in the battery pack. It circulates how much current can safely go in (charge) and come out (discharge) without damaging the battery. The current limits prevent the source usually a battery charger and the load such as an inverter from overdrawing or overcharging the battery. This protects the battery pack from cell voltages getting too high or low, which helps increase the battery’s longevity. The BMS also monitors the remaining charge in the battery. It continually tracks the amount of energy entering and exiting the battery pack and monitoring cell voltages. It uses this data to know when the battery is drained and will shut it down. This is why lithium-ion batteries don’t show sign of dying like lead-acid, but just shut off. 2.3 THE FUNCTIONS OF THE BMCS The functions of the BMCS can be discussed under the following categories; 2.3.1 DISCHARGING CONTROL The primary aim of a BMS is to maintain the battery operation in its safety zone. The BMS must monitor and protect the cell from any eventuality during discharging. Otherwise, the battery could operate beyond its limitations and this could lead to the battery damage. 2.3.2 CHARGING CONTROL Batteries are often damaged by inappropriate charging than by any other cause. Hence, monitoring how much charge that can safely go into the battery is an essential feature of the BMS. Lithium-ion batteries have a 2-stage charging method which is the constant current – constant voltage (CC-CV) charging method is employed. For the first charging stage (the constant current stage), the constant current charger produced by the charge increases the battery voltage. When the battery voltage gets to a constant value, and the battery becomes full, it enters the constant voltage (CV) stage. At this stage, the charger maintains the steady voltage as the battery current decays exponentially until the battery finishes charging. 2.3.3 STATE-OF-CHARGE DETERMINATION The BMS keeps track of the state of charge (SOC) of the battery. The SOC could signal the user and control the charging and discharging process. In the determination of SOC of the battery three methods are employed: i. Through direct measurement. ii. Through coulomb counting iii. Through the combination of the two techniques. Measuring the SOC directly could simply be done using a voltmeter because the battery voltage decreases more or less linearly during the discharging cycle of the battery. In the coulomb-counting method, the current going into or coming out of a battery is integrated to give out the relative value of its charge. Additionally, the two methods could be combined. As the actual charge approaches either end, the voltmeter could be used to regulate the battery voltage and calibrate the SOC. Meanwhile, the battery current could be integrated to determine the relative charge flowing into and coming out of the battery. 2.3.4. STATE-OF-HEALTH DETERMINATION The state of health (SOH) is a measurement the remaining capacity of the battery as % of the original capacity that reflects the general condition of a battery and its ability to deliver the specified performance. The BMS first evaluates SOH of the battery under its management and reports it. Parameters such as the internal resistance/ impedance/conductance, capacity, voltage and self-discharge, temperature of the battery during its previous uses, age of the battery can be employed in the evaluation of the SOH. 2.3.5. CELL BALANCING Cell balancing is a method of compensating weaker cells by equalizing the charge on all cells in the chain to extend the overall battery life. In chains of multi-cell batteries, small differences between the cells due to production tolerances or operating conditions tend to be magnified with each charge-discharge cycle. Weak cells may be overstressed and become even weaker until they eventually fail during charging, causing the battery to fail prematurely. To provide a dynamic solution to this problem while taking into account the age and operating conditions of the cells, the BMCS may incorporate one of the three cells balancing schemes to equalize the cells and prevent individual cells from becoming overstressed: the active balancing scheme, the passive balancing scheme and the charge shunting scheme. In active cell balancing, the charge from the stronger cells is removed and delivered to the weaker cells. In passive balancing, dissipative techniques are used to find the cells with the highest charge in the pack, as indicated by higher cell voltages. Then, the excess energy is removed through a bypass resistor until the voltage or charge matches the voltage on the weaker cells. In charge shunting, the voltage on all cells would be leveled upward to the rated voltage of a good cell. Once the rated voltage of the cell is reached, the current would bypass the fully charged cells to charge the weaker cells until they reach full voltage. 2.4 COMMUNICATIONS The communications function of a BMS may be provided though data links used to monitor performance, log data, provide diagnostics or set system parameters. The function may also be provided by a communications channel carrying system control signals. The choice of the communications protocol is not determined by the battery; instead, it is determined by the application of the battery. The central controller of a BMS communicates internally with its hardware operating at a cell level, or externally with high level hardware such as laptops, mobile phones or human computer interaction. 2.4.1 TRANSISTORS Transistors are a major component of the Battery management control system,they perform functions of switching which facilitates charging control an system monitoring. Transistor is a miniature semiconductor that regulates or controls current or voltage flow in addition amplifying and generating these electrical signals and acting as a switch/gate for them. Transistors are broadly divided into three types: bipolar transistors (bipolar junction transistors: BJTs), field-effect transistors (FETs), and insulated-gate bipolar transistors (IGBTs). A bipolar transistor is a type of transistor that uses both electrons and holes as charge carriers. Two types of bipolar transistor are manufactured: npn and pnp. A field-effect transistor is a unipolar device constructed with no pn junction in the main current- carrying path. Also, two types of field-effect transistor are manufactured: N-channel and P- channel. The MOSFET used in this project is a variation of the FET. An IGBT consists of a voltage-driven MOSFET followed by a high-current transistor. Typical schematic symbols of these transistors are shown below: Fig: 2.4.2 MONITORING Today’s batteries deliver lots of current while maintaining a constant voltage. This can lead to a runaway condition that causes the battery to catch fire. The chemicals used to construct a battery are highly volatile;a battery impaled with the right object can also make the battery catch fire. Temperature measurements aren’t just used for safety; they also can determine if it’s desirable to charge or discharge a battery. Temperature sensors monitor each cell for energy-storage-system (ESS) applications or a grouping of cells for smaller and more portable applications. Thermistors powered by an internal ADC voltage reference are commonly used to monitor each circuit’s temperature. In addition, an internal voltage reference helps reduce inaccuracies of the temperature reading versus environmental temperature changes. 2.4.5 STATE MACHINES OR ALGORITHMS Most BMCS systems require a microcontroller (MCU) or a field-programmable gate array (FPGA) to manage information from the sensing circuitry, and then make decisions with the received information. In certain devices, such as the ISL94203, includes some programmability and an encoded the algorithm to digitally enable a standalone solution with one chip. Standalone solutions are also valuable when mated to an MCU, because the standalone’s state machine can be used to free up MCU clock cycles and memory space. 2.4.6 OTHER BMCS BUILDING BLOCKS Other functional BMS blocks may include battery authentication, real-time clock (RTC), memory, and daisy chain. The RTC and memory are used for black-box applications, the RTC is used as a time stamp and memory is used for storing data. This lets the user know the behavior of battery pack prior to a catastrophic event. The battery authentication block prevents the BMS electronics from being connected to a third-party battery pack. The voltage reference/regulator is used to power peripheral circuitry around the BMS system. Finally, daisy-chain circuitry is used to simplify the connection between stacked devices. The daisy-chain block replaces the need for optical couplers or other level-shifting circuitry. 2.5 THE INTERNET OF THING (IoT) The Internet of Things (IoT) enables smart micro grid to share information for more users and it enhances connectivity throughout many infrastructures [13]. Internet of Things (IoT) is the fourth generation of supervisory control and data acquisition (SCADA), a system to monitor and control which communicates through an internet gateway. Cloud system is the best partner for data storage for IoT. Cloud system is a third party for database which transfers data over internet gateway. The advantages of cloud systems are large data storage, high reliability, low cost, and excellent scalability that can handle growing amount of work [14]. Cloud system benefits to the industries because it reduces the cost of data storage facilities and extra maintenance to keep or maintain the data. With the data in the cloud, users can process and analyze the data accurately anywhere because of large data stored in the Cloud and make faster decisions. Many studies have developed IoT for various areas and it has been implemented in various domains, for example in transportation and logistics, environment (home, office, and plant), personal and public, biomedical, and energy [15]. Energy domain based on IoT allows users to visualize energy consumption in real time. One of application from energy domain is smart grid. Application of smart grid based on IoT has been developed for contingency management using smart loads [16]. 2.8 RELATED WORKS Energy conservation is fast becoming the bedrock of developing technologies, from the transient of the usage of electric grids for power supply to its replacement with batteries. Different research and works have been and is being carried out to improve the health and performance of these batteries using Battery Management System (BMS). Below are a few BMS related works with their advantages and disadvantages. 2.8.1BMS OF AN ELECTRIC VEHICLE Jaewan Kim, Jinwoo Oh, Hoseong Lee paper on BMS of an Electric Vehicle reviews the heat generation phenomena and critical thermal issues of lithium-ion batteries. Then various battery thermal management system studies are comprehensively reviewed and categorized according to thermal cycle options. The battery thermal management system with a vapor compression cycle includes cabin air cooling, second-loop liquid cooling and direct refrigerant two-phase cooling. The battery thermal management system without vapor compression cycle includes phase change material cooling, heat pipe cooling and thermoelectric element cooling. Each battery thermal management system is reviewed in terms of the maximum temperature and maximum temperature difference of the batteries and an effective BTMS that complements the disadvantages of each system is discussed. Lastly, a novel battery thermal management system is proposed to provide an effective thermal management solution for the high energy density lithium-ion batteries [17]. Advantages • Simplicity • Low weight, cost andmaintenance, Disadvantages • Increased weight due to theaddition of heat exchangers and circuit. • System has the problems of low cooling performancedue to the low heat capacity of the air, fan noise problems andlimited space utilization. 2.8.2 MODELING OF BATTERY MANAGEMENT FOR STANDALONE PV SYSTEM B Ashok Kumar, Parthasarathy Seshadri, S Senthilrani, T S Bagavat Perumal focused on developing a model for a Battery management unit for a Solar PV based off grid standalone system and implementing the same using MATLAB tool. A secondary storage device in form a battery is essential to provide an energy backup in any autonomous system.It is essential to ensure secure function of such batteries by closely monitoring andcontrol of their State of Charge (SOC). Determination of SOC ensures the remaining energy available in the battery which further helps in discharging the same based on system requirements. Major components of this work include representation of PV source, employing MPPT, regulating the DC output via boost converter, inverter and controlling the flow of energy between the source to battery, load and vice versa [18]. Advantages • Lithium ion (Li Ion) battery has been considered for modeling offers good charge and discharge profile, high power density, occupies less space and less maintenance. • Reoccurring voltage fluctuations, slightly higher than expected. 2.8.3 BATTERY MANAGEMENT SYSTEMS (BMS) DEVELOPMENT Hossam A. Gabbar, Ahmed M. Othman and Muhammad R. Abdussami in their work analyze the details of BMS for electric transportation and large-scale (stationary) energy storage. The analysis includes different aspects of BMS covering testing, component, functionalities, topology, operation, architecture, and BMS safety aspects. Additionally, current related standards and codes related to BMS are also reviewed. The report investigates BMS safety aspects; battery technology, regulation needs, and offer recommendations. It further studies current gaps in respectto the safety requirements and performance requirements of BMS by focusing mainly on the electrictransportation and stationary application. The report further provides a framework for developing a new standard on BMS, especially on BMS safety and operational risk [19]. Advantages • BMS prevent damage from over/under voltageand cell balancing with limited charge current. • The operational benefits include safety,reliability, and dual-purpose. BMS minimizes the occurrence of a thermal runaway forhigh-voltage batteries. • BMS also identifies the faulty cells connected in series and parallel(dual-purpose). • The economic advantages of BMS are extensions of battery lifetime andlowering the cost. Disadvantages • Current BMSs have limited data logging functions. This provision helps to developthe SOC model of battery packs. • Current commercialized BMSs also lack SOC and stateof life (SOL) estimations. SOC and SOL are critical features for BMSs since both ensurescheduled operation and reliability of battery replacements. • It is quite impossible to develop a new BMS from existing BMScomponents. 2.9 SUMMARY Modeling battery management control system is a difficult process that necessitates a solid understanding of electrochemistry. However, three of the above-mentioned battery models failed to account for common battery behaviors such as self-discharging and capacity fading, making them less accurate. Because of these assumptions, neither model accurately predicted actual battery performance. The following are the assumptions: i. During the charge and discharge cycles, the internal resistance was considered to be constant and did not fluctuate with the current amplitude. ii. The models relied on the charging and discharging characteristics to determine the parameters. iii. The battery's capacity was supposed to be constant independent of the current's amplitude. iv. The models presumptively anticipated that the battery would not discharge on its own. v. It was supposed that the battery had no memory effect. vi. The model's behavior was expected to be unaffected by temperature. CHAPTER THREE DESIGN METHODOLOGY 3.0 THE BATTERY MANAGEMENT SYSTEM In this project we adopted the Tremblay’s model and modify it. The key elements that determine a battery's service life are its internal electrochemistry, physical architecture, and operation settings. As a result, in photovoltaic (PV) applications, one of the goals of battery management control systems (BMCS) is to allow the batteries to run in settings that do not diminish their service life. Monitoring and protection are two other important functions of a BMS. The current and voltage levels in the solar panels and battery bank are measured via the monitoring function. The BMS also aids in the more efficient operation of the battery. When there are significant changes in voltage levels between individual cells, the battery's performance deteriorates. To activate the equalization process to balance the cell voltages, it is important to identify the cells with high or low voltage levels. A well-balanced battery pack will deliver maximum capacity while extending the service life. Figure 3.1: Flowchart of the BMCS Algorithm 3.2 STATE OF CHARGE (SOC) CALCULATION The percentage of energy capacity still available inside the battery is referred to as SOC. Comparing the open circuit voltage (OCV) with the battery cell performance chart is the traditional approach for calculating the value of SOC. A typical SOC versus OCV chart is shown in Figure 3.2. This is a useful method, but it may not provide accurate results. This is due to the fact that during the charge period, the battery voltage is higher than the actual OCV value, while during the discharge time, it is lower. This inaccuracy grows as the current decreases, and the OCV does not fully settle until several hours after the current is zero. As a result, the "coulomb counting approach" must be utilized to acquire an accurate SOC value during the charge/discharge interval. Before the charge/discharge procedure, the OCV technique generates the initial SOC value. Because of the current sensor measurement offset, the threshold for selecting OCV or coulomb counting is ± 0.5A. The pseudo code for SOC calculation is as follows: If operation current -0.5A < I < 0.5A Then SOCOCV = Slope * OCV – parameter value (3.1) If operation current, I > 0.5A or I < -0.5A Then SOCCC = SOCini + ΔSOC (3.2) and ΔSOC = = (3.3) Where SOCOCV = state of charge value from open circuit voltage method SOCCC = state of charge value from coulomb counting method = total coulombs of electric charge Cap = the capacity of battery or battery bank Figure 3.2 Example of SOC versus OCV Chart. 3.2.1 STATE OF CHARGE (SOC) MONITORING Battery SOC is very important information to make sure that the user knows the remaining energy. There are three different SOC monitoring methods are evaluated and compared. They are based on Ah (Ampere hours) counter, open circuit voltage and artificial neural network. The first one is very effective for constant current discharge but, it is very sensible to error when several charge/discharge is executed in a row. The open circuit voltage can be effectively adopted when the open circuit voltage, after battery resting period, is not a problem. The third method is based on using an artificial neural network. It is well known that an artificial neural network can be very effective when data for its training are reliable. 3.4 HARDWARE COMPONENTS Solar Module Solar Module is a source of energy, which generates DC power using Photovoltaic effect. Solar Module is formed after connecting multiple solar cells connected in series to form desired current and voltage. In this project, solar modules will be used in order to charge Lithium Ion Battery. A 40V solar module is used in this project.A typical solar module is shown below; Figure 3.3: Solar Module. LED A light-emitting diode is a semiconductor light source that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The LEDs used in this project functions as battery one,battery two and solar indicators. They are also used as directional diodes to check the direction of the voltage to prevent reverse voltage from occurring. Figure 3.4: LED. Lithium Ion Battery: A lithium-ion (Li-ion) battery is an advanced battery technology that uses lithium ions as a key component of its electrochemistry. During a discharge cycle, lithium particles in the anode are ionized and isolated from their electrons. The lithium particles move from the anode and go through the electrolyte until they arrive at the cathode, where they recombine with their electrons and electrically neutralize. The lithium particles are sufficiently little to have the option to travel through a small scale porous separator between the anode and cathode. To a limited extent in view of lithium’s little size (third just to hydrogen and helium), Li-ion batteries are fit of having an exceptionally very high voltage and charge storage per unit mass and unit volume. Figure 3.5: Generic Lithium-ion Batteries. Voltage sensor A voltage sensor is a sensor used to calculate and monitor the amount of voltage in an object. Voltage sensors can determine the AC voltage or DC voltage level. The input of this sensor is the voltage, whereas the output is the switches, analog voltage signal, a current signal, or an audible signal.Some applications of Voltage Sensors are; Power failure detection, Load sensingSafety switching, Temperature control, Power demand control,Fault detection etc. A typical voltage sensor is shown below. Figure 3.6: Voltage sensor. Current Sensor (ACS758) The sensor gives precise current measurement for both AC and DC signals.The thickness of the copper conductor allows survival of the device at high overcurrent conditions. The ACS758 outputs an analog voltage output signal that varies linearly with sensed current. This current sensor enables the monitoring of currents in projects every second for energy saving or circuit protecting purposes, supported with the fact that the sensor is Arduino interface compatible, 120 kHz typical bandwidth, 3 μs output rise time in response to step input current, Output voltage proportional to AC or DC currents, Factory-trimmed for accuracy and Extremely stable output offset voltage [20]. Figure 3.7:Current Sensor (ACS758). SPECIFICATION • Operating Voltage(analog): 3.3-5V • Peak Measuring Voltage:3000V(AC),500V(DC) • Current Measuring Rang:-50~100A • Sensitivity:40 mV/A • Operating Temperature: -40~150°C • Dimension:34x34mm(1.34x1.34") Arduino UNOWi-Fi Module (esp8266) An ESP8266 Wi-Fi module is a microchip mainly used for the development of end-point IoT (Internet of things) applications. It is referred to as a standalone wireless transceiver, and is a self- contained SoC with integrated TCP/IP protocol stack that can give access to a Wi-Fi network. One useful feature of UNO Wi-Fi is support for OTA (over-the-air) programming, either for transfer of Arduino sketches or Wi-Fi firmware. The Arduino UNO Wi-Fi is based on the ATmega328P with an ESP8266 802.11 b/g/n 2.4GHz Wi-Fi moduleintegrated. It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz ceramic resonator, a USB connection, a power jack, an ICSP header, and a reset button. It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with an AC-to-DC adapter or battery to get started. The board can operate on an external supply of 6 to 20 volts. If supplied with less than 7V, however, the 5V pin may supply less than five volts and the board may be unstable. If using more than 12V, the voltage regulator may overheat and damage the board. The recommended range is 7 to 12 volts. The power pins are as follows: • VIN.The input voltage to the Arduino board when it's using an external power source (as opposed to 5 volts from the USB connection or other regulated power source). Voltage can be supplied through this pin. • 5V.this pin outputs a regulated 5V from the regulator on the board. The board can be supplied with power either from the DC power jack (7 - 12V), the USB connector (5V), or the VIN pin of the board (7-12V). Supplying voltage via the 5V or 3.3V pins bypasses the regulator, and can damage your board. • 3V3. A 3.3 volt supply generated by the on-board regulator. Maximum current drawn is 1 A (according to the power input source). • GND. Ground pins. • IOREF. This pin on the Arduino board provides the voltage reference with which the microcontroller operates. A properly configured shield can read the IOREF pin voltage and select the appropriate power source or enable voltage translators on the outputs for working with the 5V or 3.3V supplies. Input and Output Each of the 14 digital pins on the UNO can be used as an input or output, using pinMode(), digitalWrite() and digitalRead() functions. They operate at 5 volts. Each pin can provide or receive a maximum of 40 mA and has an internal pull-up resistor (disconnected by default) of 20- 50 kΩ. In addition, some pins have specialized functions: • Serial: 0 (RX) and 1 (TX). Used to receive (RX) and transmit (TX) TTL serial data. These pins are connected to the corresponding pins of the ATmega8U2 USB-to-TTL Serial chip. • External Interrupts: 2 and 3. These pins can be configured to trigger an interrupt on a low value, a rising or falling edge, or a change in value. See the attachInterrupt() function for details. • PWM: 3, 5, 6, 9, 10 and 11. Provide 8-bit PWM output with the analogWrite() function. • SPI: 10 (SS), 11 (MOSI), 12 (MISO), 13 (SCK). These pins support SPI communication using the SPI library. • LED: 13. There is a built-in LED connected to digital pin 13. When the pin is HIGH value, the LED is on, when the pin is LOW, it's off. The UNO has 6 analog inputs, labeled A0 through A5, each of which provide 10 bits of resolution (i.e. 1024 different values). By default they measure from ground to 5 volts, though is it possible to change the upper end of their range using the AREF pin and the analogReference() function. Additionally, some pins have specialized functionality: • TWI: A4 or SDA pin and A5 or SCL pin. Support TWI communication using the Wire library. • AREF. Reference voltage for the analog inputs. Used with analogReference(). • RESET. Bring this line LOW to reset the microcontroller. Typically used to add a reset button to shields which block the one on the board [21]. Figure 3.8: Back and Front view of Arduino UNO Wi-Fi module. Arduino Nano Arduino is an open-source gadget which is easy to utilize and programmed. Arduino Uno has total 14 pins, from which 6 pins provide PWM output and 6 pins provides analog inputs. Instructions as well as programming are fed through portable drive. For this you can use the programming language and the Software (IDE) arguing. There are total 14 digital Pins and 8 Analog pins on your Nano board. The digital pins can be used to interface sensors by using them as input pins or drive loads by using them as output pins. A simple function like pinMode() and digitalWrite() can be used to control their operation. The operating voltage is 0V and 5V for digital pins. The analog pins can measure analog voltage from 0V to 5V using any of the 8 Analog pins using a simple function like analogRead(). These pins apart from serving their purpose can also be used for special purposes, which are discussed below: • Serial Pins 0 (Rx) and 1 (Tx): Rx and Tx pins are used to receive and transmit TTL serial data. They are connected with the corresponding ATmega328P USB to TTL serial chip. • External Interrupt Pins 2 and 3: These pins can be configured to trigger an interrupt on a low value, a rising or falling edge, or a change in value. • PWM Pins 3, 5, 6, 9 and 11: These pins provide an 8-bit PWM output by using analogWrite() function. • SPI Pins 10 (SS), 11 (MOSI), 12 (MISO) and 13 (SCK): These pins are used for SPI communication. • In-built LED Pin 13: This pin is connected with a built-in LED. When pin 13 is HIGH – LED is on and when pin13 is LOW, it is off. • I2C A4 (SDA) and A5 (SCA): Used for IIC communication using Wire library. • AREF: Used to provide reference voltage for analog inputs with analogReference() function. • Reset Pin: Making this pin LOW, resets the microcontroller. There are total three ways by which you can power the Arduino Nano. • USB Jack: Connect the mini USB jack to a phone charger or computer through a cable and it will draw power required for the board to function • Vin Pin: The Vin pin can be supplied with an unregulated 6-12V to power the board. The on-board voltage regulator regulates it to +5V. • +5V Pin: If you have a regulated +5V supply then you can directly provide this o the +5V pin of the Arduino [22]. Figure 3.9: Arduino Nano. LCD Display: LCD (Liquid Crystal Display) is used to monitor the battery voltage & current and Temperature, 16x2 LCD displays are used with the Arduino Microcontroller for measurement and display. Figure 3.10: LCD. MOSFET&BJT MOSFETs or Metal Oxide Silicon Field Effect Transistors were invented to overcome the disadvantages posed by FETs, such as the slow operation, high drain resistance, and moderate input impedance. BJT or Bipolar Junction Transistor Figure 3.11: MOSFET&BJT. Relay switches A relay is an electrically operated switch. It consists of a set of input terminals for a single or multiple control signals, and a set of operating contact terminals. The switch may have any number of contacts in multiple contact forms, such as make contacts, break contacts, or combinations thereof. The design and types of relay switching circuits is huge, but many small electronic projects use transistors and MOSFETs as their main switching device as the transistor can provide fast DC switching (ON-OFF) control of the relay coil from a variety of input sources so here is a small collection of some of the more common ways of switching relays. Figure 3.12: Relay Switch. RESISTORS A resistor is an electronic device with the characteristic property of resistance, that is, it opposes the flow of electric charge. Resistors obeys ohm’s law at all times, implying that the current I flowing through a given resistor is directly proportional to the potential difference V, applied across it, provided the temperature and other physical factors are constant. In this project resistors were selected based on this property. Figure 3.13: Resistors. CAPACITORS A capacitor is an electronic device that is capable of storing electric charge equal to ½CV2 joules. This charge is measured in coulombs and has a symbol Q. A simple capacitor consists of two conducting plates or semiconducting plates separated by a dielectric material. Figure 3.14: Capacitor. 3.5 SOFTWARE COMPONENT Software design was required to integrate the system with the hardware. Arduino Uno was used as the microcontroller or the brain of the system. Similar to the hardware, the software also divided into two-phase, i.e. charging and discharging. 3.6 BMS SOFTWARE FLOWCHART 3.7 CIRCUIT DIAGRAM 3.7.2 CIRCUIT ANALYSIS AND PRINCIPLES OF OPERATION The Battery Management Control System(BMCS) circuit incorporates all components to achieve its aim of monitoring and switching. The B2 (Battery 2) represents the solar panel module which supplies the system with 40V DC power supply, and is connected to the positive input pin of the current sensor (ACS712) IC for current measurement. The pin A3 of the sensor is connected to the arduino Nano and the 220μF capacitor C2 connected to the filter pin for smoothing of the current sensor signal. Resistors R1 and R2 are used to measure the voltage of the solar panel after the current has been measured, thus acting as a voltage sensor with a 0.01μF capacitor C1 connected across R2 for smoothing so as to prevent voltage fluctuations with varying sun intensity and keep the voltage constant as reading are taken. D1 is a directional diode used to check the direction of the voltage to prevent reverse voltage. The IRF4905 MOSFET is a p-channel MOSFET, when the current passes through D2 switching occurs through R4 and Q3 which is the switching transistor (for opening and closing of the gate) and R3 the shunt resistor to input voltage when the MOSFET is to remain closed, it supplies positive voltage from the power supply to the base of the MOSFET i.e. the resistor R3 acts as a pull up resistor which is also used to switch the MOSFET when no input signal is received or when the battery is full and no longer charging. The D2 through R4 is used to switch OFF the MOSFET. The solar panel voltage switched will be regulated down to (28-30)V, and the first relay RL1 will be used to charge the batteries B1 and B3, which will be charged to their full battery capacity of 12-14v each. When the two batteries are full and their voltage needs to be equalized due to discharging of one or both batteries, the RL1 is switched to channel the MOSFET Q1. In the event of voltage variation between BI and B3, if B3 is to be charge to achieve equalization, the polarity of the middle point is changed to disconnected the negative of the battery B1 wsing RL3 and move it to the normally open which will leave only B3 charging. If B1 is to be charged, it switches the RL2 and the transistor Q7 is used to switch R7 through pin D5 while Q1 is switched through Q4 via the terminal D4 of the arduino. When the program is activate and ran through the arduino IDE, the LCD (16*2) connected to the arduino is turned ON and gives regular readings as the State of Charge, voltage and current levels are continually being measured. 3.8 SYSTEM FLOW CHART 3.9 SYSTEM BLOCK DIAGRAM CHAPTER FOUR 4.0 DESIGN 4.1DESIGN OF THE CIRCUIT The actual design of the Battery Management Control System was done using Proteus ISIS software, where it was simulated to check the correct working of the circuit. In the course of the simulation on Proteus ISIS the 40V solar module was replaced with a battery (B1) of 40V as seen in the circuit diagram, since Proteus ISIS does not yet make provision for solar panel as a component. Regardless the battery was able to serve and substitute for the panel and the schematic diagram was redrawn to be understood and transferred easily on the Vero board after testing on breadboard. 4.1.1 TOOLS AND PROCEDURES APPLIED IN THE PROJECT ASSEMBLING This construction finally lied on the PCB with all the connections strictly followed to the breadboard connection. Necessary procedures were followed to avoid short circuit, wrong connection and improper fittings of components. Then, the components were finally soldered in the PCB following the holes under normal temperature. The following tools were used in the assembling of this project. i. Screw driver ii. Pliers iii. Soldering iron and sucker iv. Hacksaw for cutting heat sink v. Files for smoothening rough surfaces. vi. Drilling machine / hand drill. vii. Cutting machine for cutting. 4.1.2 INSERTION OF COMPONENT AND SOLDERING A lay out diagram of the various unit of the system and how they are interconnected in the diagram by conducting paths which thickness depends on the current flowing through the path. With the aid of the circuit diagram, the components were inserted into their designed positions and soldered in place. The results are shown in the diagrams below; Fig 4.0: Front view of soldered components (part circuit). Fig 4.1: Back view of soldered components (part circuit). Figure 4.2: Complete Circuit. 4.1.3 CASING The entire circuits and LCD were housed in a rectangular box, length of 10inches, height 5inches and a breath of 5 inches. This box is of a light weight, with diode indicators, an input cord of 40 volts DC form the solar module. 4.1.4 PRECAUTION The following precautions were taken in the construction process; • The layout diagram was studied carefully to ensure that it conforms with the schematic diagram before it was transformed to the Vero board. • The board was not left too long in the enchant solution in order to avoid damaging. • Multi-meter is used in order to locate open or short circuits, and Polarized components were inserted into board correctly. • The switching devices (MOSFETS and BJT) which are sensitive were handled by their protective cover when soldering them in place in order to avoid damage to the device as a result to electrostatic discharges from the head. • Ohmic tests and visual checks were carried out on the entire circuit in order to locate open or short circuit faults before applying power to the circuit so as to avert component damaged. 4.2 TESTING In testing the system, four basic steps were taken. These steps are sequentially listed below as: 1) Using Proteus ISIS, the individual stages and the complete systems were simulated. Required results were obtained from computer model. 2) All components were tested using digital multi meter, failed components were replaced before proceeding to construction. 3) Each unit of the circuit was tested to measure the required result. 4) To ensure that there was no breakage in the circuit path on the Vero board, immediately after soldering on Vero board, the circuit path was tested using the Digital Multi-meter. This was done to also ensure continuity of circuit on the Vero board. After the completion of this project, each unit was tested to ensure proper operation of the device. The expected output voltage, current, and power were measured using Multi-meter and wattmeter 4.4 COST OF PRODUCTION Table 4.0:List of Components S/N COMPONENTS QUANTITY PRICE/ITEM TOTAL/ITEM 2 Arduino nano 1 6,000 6,000 3 WiFi module esp8266 1 5,000 5,000 5 ACS785 1 4,500 4,500 6 12V Relay 3 200 600 8 MOSFET(IRF4905) 2 50 100 9 BJT(2N3904 &2N2222) 5 30 150 10 Resistors 25 10 250 11 Capacitors 3 30 90 12 Diodes 5 10*3/300*2 630 13 LCD(16*2) 1 1,500 1,500 14 Connectors 3 200 600 15 Female Connector 1 200 200 16 Screws 7 20 140 17 Wires 3 150 450 18 LED 8 10 80 19 Lead 10 70 700 TOTAL 20,990 4.6 SYSTEM SPECIFICATIONS. Figure 4.1:System Specification. S/N Parameter Specification 1 Split charge current 40A 2 Equalizing Voltage 14.4V 3 Equalizing Current 40A 4 Maximum charge current 50A 5 Voltage rating 24V 6 Current rating 60A 7 Dissipation power 2s 8 BMS type Voltage controller 9 Application Inverter Battery 10 Power supply voltage 30V-40V max 11 Switch mode PWM 12 Overcharge protection Available 13 Over Drain protection Not available CHAPTER 5 CONCLUSIONS AND RECOMMENDATIONS 5.1 CONCLUSION This paper has shownthe designing, monitoring and management of Solar PV Li-ion battery. SoC is estimated by using direct measurement,Coulomb counting method orthrough the combination of the two techniques.The battery management technology will play major role in reliable and economic operation of the solar PV system. The cost of the electricity can be decreased or maintained by using battery management system, thereby improving life of the battery. The system is design in order to regulate power and voltage, and also reduce the fluctuation in the system. The varying conditions can tends to leave the batteries in a state of overcharge or deep discharge both these conditions of the battery have adverse effect on lifespan of the battery. The BMS will utilize charge controllers to enable maximum safety to the solar panel to be delivered to the battery, thus is very important for BMS to well-maintained the battery reliability and safety, the state monitoring and evaluation, cell balancing and charge controls are well functional. After implementation of battery management control system, the lifespan of the battery is much longer than the one without it and to ensure the battery operating within safe operating system. Nevertheless, due to varying situation, there is no standard solution setting for BMS performance and different strategies still need to be applies to improve the performance of BMCS for applications. 5.2 FUTURE WORK AND RECOMMENDATIONS The limitation of this project is that it stops at the diagnosis and analysis level of the battery to give users information. To go further, in subsequent research a tool to proffer solutions and render corrective maintenance remotely from the app will be a welcomed development. REFERENCE [1] H.J. Bergveld, Battery Management Systems Design by Modeling, 2001, ISBN 90-74445-51- 9 [2] Irsyad N. H., Edi Leksono, M. Iqbal, FX Nugroho S., Nugraha, DeddyKurniadi, Brian Yuliarto, Development of Battery Management System for Cell Monitoring and Protection, IEEE Int. Conf. on Elect. Engineering and Computer Science, pp. 24-25 Nov. 2014. [3] Y. Xing, E. W. M. Ma, K. L. Tsui, and M. Pecht, Battery Management Systems in Electric and Hybrid Vehicles, Energies, vol. 4, no. 12, pp.1840–1857, Oct. 2011. [4] M Prochaska, C. Fabich, “Stromkonserve, Akkutechnologien: Von Blei bis Lithium- Ion”, ELRAD, Heft 12, pp. 54-75, 1994 [5] M. Barak (Ed.), T. Dickinson, U. Falk, J.L. Sudworth, H.R. Thirsk, F.L. Tye, Electrochemical Power Sources: Primary & Secondary Batteries, IEE Energy Series 1, A. Wheaton &Co, Exeter, 1980 [6] D. Linden, Handbook of Batteries, Second Edition, McGraw-Hill, New York, 1995 [7] R.A. Powers, “Batteries for Low Power Electronics”, Proceedings of the IEEE, vol. 83, no. 4, pp. 687-693, April 1995 [8] P.H.L. Notten, “Rechargeable Nickel-MetalHydride Batteries: a Successful New Concept”, Interstitial Intermetallic Alloys, chapter 7 in NATO ASI Series E 281, vol. 151, F. Grand-jean, G.J. Long and K.H.J. Buschow, Ed., 1995 [9] P.H.L. Notten, J.R.G. van Beek, “Nickel-MetalHydride Batteries: from Concept to Characteristics”, Chemical Industry, vol. 54, pp. 102-115, 2000 [10] L. Atzori, A. Iera, and G. Morabito, The Internet of Things: A Survey, Computer Networks 54, pp.2787-2805, June 2010. [11] ShiliangLuo, Bin Ren, The Monitoring and Managing Application of Cloud Computing Based on Internet of Things, Elsevier, Computer Methods and Program in Biomedicine 130 (2016) 154-161. [12] Fei Tao, Y. Wang, Y. Zuo, H. Yang, M. Zhang, Internet of Things in product life-cycle energy management, Journal of Industrial Integration 1 (2016) 26- 39. [13] S. Ciavarella, Jhi-Young Joo, S. Silvestri, Managing Contingencies in Smart Grids via the Internet of Things. IEEE Trans. on Smart Grid, Vol. 7, No. 4, July 2016. [14] Shepherd, C. M., Design of Primary and Secondary Cells - Part 2. An equation describing battery discharge, Journal of Electrochemical Society, Volume 112, July 1965, pp 657-664. [15] Olivier Tremblay, Louis A. Dessaint, Experimental Validation of a Battery Dynamic Model for EV Applications, World Electric Vehicle Journal Vol. 3 - ISSN 2032-6653 [16] Wagner, R., Sauer, D. U. ―Charge strategies for valve-regulated lead/acid batteries in solar power applications Journal of Power Sources, Vol. 95, Issue 1-2, pp. 141-152, March, 2001. [17] J. Kim, J. Oh, and H. Lee, “Review on battery thermal management system for electric vehicles,” vol. 149, no. December 2018, pp. 192–212, 2019. [18] B. Dynamics et al., “Modeling of Battery Management for Standalone PV System Modeling of Battery Management for Standalone PV System,” doi: 10.1088/1742- 6596/2115/1/012027. [19]H. A. Gabbar, A. M. Othman, and M. R. Abdussami, “Review of Battery Management Systems ( BMS ) Development and Industrial Standards,” 2021. [20]https://pdf1.alldatasheet.com/datasheet-pdf/view/174119/ALLEGRO/ACS712ELCTR-30A- T.html [21]https://www.elprocus.com/esp8266-wi-fi-module/ [22]https://www.arduino.cc/en/uploads/Main/ArduinoNanoManual23.pdf https://google.com/ :Components image source. APPENDIX A #include #include // Definitions : #define solar_volt_sense 0 // defining the analog pin A0 to read solar panel Voltage #define bat_volt_sense 1 //defining the analog pin A1 to read battery voltage #define solar_current_sense 3 //defining the Analog pin A2 to measure load current #define AVG_NUM 10 // number of iterations of the adc routine to average the adc readings //#define ONE_WIRE_BUS 12 // Data wire of DS18B20 temp sensor is plugged into pin 3 on the Arduino #define pwm_pin 3 // defining digital pin D9 to drive the main MOSFET Q1 @ 1KHz //Defining led pins for indication #define BULK_CHRARGE_SP 14.4 #define FLOAT_CHARGE_SP 13.5 #define Charge_Restart_SP 13.2 #define BULK_CHRARGE_SP2 28.8 #define FLOAT_CHARGE_SP2 27.0 #define Charge_Restart_SP2 26.4 #define MIN_SOLAR_VOLT2 20 #define LVD2 23.0 #define LVR2 25.0 #define MIN_SOLAR_VOLT 10 #define LVD 11.5 #define LVR 12.5 #define ABSORPTION_LIMIT 3600000 // 1 hour in milliseconds #define NIGHT_TIME 3600000 // 1 hour in milliseconds #define CHARGER_RESTART_TIME 600000 // 10 mins in milliseconds #define EVENING_TIME 300000 // 5mins in milliseconds #define MORNING_TIME 180000 // 3mins in milliseconds #define offsetVoltage 2.5 // for ACS712 sensor #define Sensitivity 0.185 // 185mV/A for ACS712-5A variant //Declaring the global variables int battery = 1; float solar_volt=0; // solar panel voltage float bat_volt=0; // battery voltage float solar_current=0; float temperature=0; // temperature float temp_change=0; // temperature difference between current and refrence ( 25 degC) float pwm_duty=0; // PWM Duty Cycle (0 to 1024) float bulk_charge_sp=0; // Bulk charging set point float error=0; // calculate the difference between battery voltage and bulk charge set point float float_charge_sp=0; // Float charging set point const int bat_type = 0; int Input_two = 24; int Setpoint_two = 29.0 //Flooded=0,AGM=1 unsigned long absorption_time; // to keep track of today's time in absorption state unsigned long charger_millis; // to keep track of time for charger unsigned long restart_time; unsigned long morn_timer; unsigned long even_timer; float solar_watts=0; float solar_wattHours=0; unsigned long time =0; unsigned long last_time=0; unsigned long current_time=0; // Variables for PID Controller //Define Variables we'll be connecting to double Setpoint, Input, Output; double int Input_two, Setpoint_two, Output_two; //Specify the links and initial tuning parameters PID myPID(&Input, &Output, &Setpoint,2,5,1, DIRECT); // Here Kp= 2 , Ki= 5 and Kd=1 // aggKp=4, aggKi=0.2, aggKd=1; PID myPID_two(&Input_two, &Output_two, &Setpoint_two,2,5,1, DIRECT);); // Set the pins used for LCD connections: // addr, en,rw,rs,d4,d5,d6,d7,bl,blpol LiquidCrystallcd(7, 2, 4, 6, 8, 9); // Set the LCd pins enumcharger_state {off, bulk,absorption,Float} charger_state ; //---------------------------------------- Set Up Function----------------------------------------------------- void setup() { Serial.begin(9600); // open the serial port at 9600 bps: pinMode(pwm_pin,OUTPUT); TCCR2B = TCCR2B & B11111000 | 0x03; // pin 3 PWM frequency of 980.39 Hz //initialize the variables we're linked to if(analogRead(bat_volt_sense)>= 17){ Input_two = 24; Setpoint_two = 29.0; } else{ Input = 12; Setpoint = 14.5; } //turn the PID on myPID.SetMode(AUTOMATIC); myPID_two.SetMode(AUTOMATIC); charger_state = off; // start the charger from off charger_millis = millis() ; // initialise the local clock lcd.begin(16,2); // initialize the lcd for 20 chars 4 lines, turn on backlight lcd.clear(); delay(1000); // pause to properly start up the Arduino } //-----------------------------------------------------------Main Loop------------------------------------------ void loop() { read_sensors_data(); // Reading voltage temp from the sensors get_setpoint(); // Reading temp compensated charging set point run_charger(); power(); lcd_display(); serial_print(); } //--------------------------------Function Definition --------------------------------// //READING DIFFERENT SENSORS DATA // /* This function read the voltage dividers and temperature sensor (DS18B20 probe),gives row adc values in between 0-1023 Then adc value is calibrated to get the actual voltages and currents */READS AND AVERAGES THE ANALOG INPUTS (SOLAR VOLTAGE,BATTERY VOLTAGE)/* int read_adc(int adc_parameter) { int sum = 0; int sample ; for (int i=0; i 1 ADC value = (5/1024)Volt= 0.0048828Volt // Vout=Vin*R2/(R1+R2) => Vin = Vout*(R1+R2)/R2 R1=100 and R2=20 solar_volt = read_adc(solar_volt_sense)*0.00461*(120/20); bat_volt = read_adc(bat_volt_sense)*0.00461*(120/20); if(bat_volt>= 17){ battery = 1; } else if(bat_volt ( bat_volt + 0.5) ) && ( absorption_time> ABSORPTION_LIMIT ) ){ charger_millis = millis() ; restart_time = 0 ; charger_state = Float ; } else{ if (millis() - charger_millis> NIGHT_TIME) absorption_time = 0 ; pwm_duty = 0; analogWrite(pwm_pin, pwm_duty); //generate PWM from D3 @ 0% duty // Shut down the charger } /////////////////////////////////// STAGE-1 (BULK CHARGING)/////////////////////////////////////////////// // During this stage the MOSFET is fully on by setting the duty cycle to 100% // Constant Current Charging ///////////////////////////////////////////////////////////////////////////////////////////////////////////////// case bulk : if ( solar_voltbulk_charge_sp) && ( solar_volt> ( bat_volt + 0.5) ) && ( absorption_time< ABSORPTION_LIMIT )){ charger_millis = millis() ; charger_state = absorption ; } else if ( (bat_volt>float_charge_sp) && ( solar_volt> ( bat_volt + 0.5) ) && ( absorption_time> ABSORPTION_LIMIT )){ charger_millis = millis() ; restart_time = 0 ; charger_state = Float ; } else{ pwm_duty = 255; analogWrite(pwm_pin,pwm_duty); //generate PWM from D3 @ 100% duty // MOSFET Q1 is ON if( bat_volt>bulk_charge_sp ) { charger_state = absorption ; } } break; // end of case bulk condition /////////////////////////////////// STAGE-2 (ABSORPTION CHARGING)////////////////////////////////////////////////////// // During this stage the MOSFET is partially on by setting the duty cycle to between 0% and 100% // Constant voltage ///////////////////////////////////////////////////////////////////////////////////////////////////////////////// case absorption : if ( solar_voltfloat_charge_sp) && ( solar_volt> ( bat_volt + 0.5) ) && ( absorption_time> ABSORPTION_LIMIT )){ charger_millis = millis() ; charger_state = Float ; } else{ // increment absorption timer and test for duration in absorption state absorption_time = absorption_time + millis() - charger_millis ; charger_millis = millis(); /* error = (bat_volt - bulk_charge_sp); // duty cycle reduced when the battery voltage approaches the charge set point and vice versa if (abs(error) 255)pwm_duty=255; analogWrite(pwm_pin, pwm_duty); } break; // end of case absorption condition /////////////////////////////////// STAGE-3 (FLOAT CHARGING)////////////////////////////////////////////////////// // During this stage the MOSFET is partially on by setting the duty cycle between 0% and 100% // Constant Voltage Charging ///////////////////////////////////////////////////////////////////////////////////////////////////////////////// case Float : if ( solar_volt CHARGER_RESTART_TIME)){ charger_millis = millis() ; charger_state = bulk ; } else if ( ( bat_volt>float_charge_sp) && ( solar_volt> ( bat_volt + 0.5) ) && ( absorption_time< ABSORPTION_LIMIT )){ charger_millis = millis() ; charger_state = absorption ; } else{ if (bat_volt>float_charge_sp){ pwm_duty--; if(pwm_duty