Modelling of Multi Inductor based Balancing of Battery Pack for Electrical Mobility

   The pre requisite for success of electrical mobility is driven by development of battery technologies. Reliable performance of electrical mobility necessitates for high energy density battery packs. The advent of Li ion cell chemistry revolutionised the electric and hybrid vehicle advancement due to its high energy density, lighter weight and wide range of temperature performance. Higher operating voltages of the battery are achieved by configuration of the cells in series and parallel combinations. The performance of these battery packs are affected by operating temperature and imperfections in manufacturability which causes mismatches in cell impedance, cell potential and state of charge (SOC) imbalance. These performance issues are overcome by cell and battery balancing techniques. In this paper, a dynamic battery pack balancing circuit by using multi inductor with SOC based logic controller for both cell and battery balancing are presented. The battery pack balancing performances during static, charging, discharging conditions are analysed

Performance Analysis of Energy Storage in Smart Microgrid Based on Historical Data of Individual Battery Temperature and Voltage Changes

In this work, a historical data based battery management system (BMS) was successfully developed and implemented using an embedded system for condition monitoring of a battery energy storage system in a smart microgrid. The performance was assessed for 28 days of operating time with a one-minute sampling time. The historical data showed that the maximum temperature increment and the maximum temperature difference between the batteries were 4.5 °C and 2.8 °C. One of the batteries had a high voltage rate of change, i.e. above 3.0 V/min, and its temperature rate of change was very sensitive, even at low voltage rate of changes. This phenomenon tends to indicate problems that may deplete the battery energy storage system's total capacity. The primary findings of this study are that the voltage and temperature rates of change of individual batteries in real operating conditions can be used to diagnose and foresee imminent failure, and in the event of a failure occurring the root cause of the problem can be found by using the historical data based BMS. To ensure further safety and reliability of acceptable practical operating conditions, rate of change limits are proposed based on battery characteristics for temperatures below 0.5 °C/min and voltages below 3.0 V/min

A review on power electronic converters for modular BMS with active balancing

Electric vehicles (EVs) are becoming increasingly popular due to their low emissions, energy efficiency, and reduced reliance on fossil fuels. One of the most critical components in an EV is the energy storage and management system, which requires compactness, lightweight, high efficiency, and superior build quality. Active cell equalization circuits such as those used in battery management systems (BMS) have been developed to balance the voltage and state of charge (SoC) of individual cells, ensuring the safety and reliability of the energy storage system. The use of these types of equalization circuits offers several benefits including improved battery performance, extended battery life, and enhanced safety, which are essential for the successful adoption of EVs. This paper provides a comprehensive overview of the research works related to active cell equalization circuits. This review highlights the important aspects, advantages and disadvantages, and specifications.This work was supported by FCT—Fundação para a Ciência e Tecnologia, within the R&D Units Project Scope UIDB/00319/2020. Luis A. M. Barros is supported by the doctoral scholarship PD/BD/143006/2018, granted by the Portuguese FCT foundation

A comprehensive working state monitoring method for power battery packs considering state of balance and aging correction.

A comprehensive working state monitoring method is proposed to protect the power lithium-ion battery packs, implying accurate estimation effect but using minimal time demand of self-learning treatment. A novel state of charge estimation model is conducted by using the improved unscented Kalman filtering method, in which the state of balance and aging process correction is considered, guaranteeing the powered battery supply reliability effectively. In order to realize the equilibrium state evaluation among the internal battery cells, the numerical description and evaluation is putting forward, in which the improved variation coefficient is introduced into the iterative calculation process. The intermittent measurement and real-time calibration calculation process is applied to characterize the capacity change of the battery pack towards the cycling maintenance number, according to which the aging process impact correction can be investigated. This approach is different to the traditional methods by considering the multi-input parameters with real-time correction, in which every calculation step is investigated to realize the working state estimation by using the synthesis algorithm. The state of charge estimation error is 1.83%, providing the technical support for the reliable power supply application of the lithium-ion battery packs

Charging tests on a photovoltaic panel for solar cookers

This research project focuses on the process, development and outcome of collecting and storing energy through photovoltaic panels connected to batteries. The main aims of the project are: to find out if the batteries can be used to store energy while simultaneously having a load connected to the photovoltaic panel; to carry out an experimental campaign for a realistic device; to learn how the charge controller works; to experiment first-hand with real material in a laboratory and outdoors; and to see if this system could be economically feasible especially as an alternative energy source for cooking in developing countries. This system would allow the user to consume electricity during the day, for example for cooking, while the batteries are being charged so that when there is no sunlight, like at night, electricity supply would still be available. The implementation of photovoltaic panels along with storage batteries could solve many electrical supply problems worldwide. For instance, in developing countries where there is less and less firewood and its use is unhealthy due to poor ventilation of houses, in places where electricity is unaffordable or non-existent and where poorer populations of the world cannot find other means of fuel for cooking or to provide for their minimal energy needs. Throughout this project the main components of a photovoltaic system will be explained as well as some basic concepts related to solar energy. An in depth analysis of the experimental results obtained will also be made. In order to show the positive impact these kinds of systems could have in certain areas of the world, the energy access situation in developing countries is analysed and a specific case study is applied for Nigeria. In the conclusions of this project the objectives achieved are mentioned, such as being able to decipher the functioning of the charge controller of the device used or being able to carry out an experimental characterization campaign of a realistic device.Ingeniería de la Energí