Active balancing circuit for advanced lithium-ion batteries used in photovoltaic application

Abstract

Abstract. An approach to the analysis and design of a bidirectional DC power converter for the cell voltage balancing control of a series connected lithium-ion battery string is presented in this paper. The proposed Cell Balancing Circuit (CBC) is designed to transfer the energy from the fully charged battery cell to the weakest one using a switch mode power converter operation. This operation maintains cell batteries at the same State-Of-Charge (SOC) and voltage range. Unlike previous battery balancing circuits, the balancing method uses only one magnetic component, resulting small size system. Simulation and experimental results show that the proposed cell balancing method can not only enhance the bidirectional battery equalization performance, but can also reduce the switching loss during the equalization period. Experiment results are provided to verify the operating principle of the proposed balancing method. Specific conditions of experiments are used to reproduce photovoltaic operations.

A Review on Power Electronic Converters for Modular BMS with Active Balancing

“…In addition, as illustrated in Figure 9, for a battery formed by n cells in series, 2n + 2 controlled semiconductors, S xy , and 2n + 2 diodes, D xy , are necessary, where x represents the conduction orientation and considering the image can be 1 or 2. and y identifies the number of arms and considering the image can be a, b, c, or d. This converter presents advantages such as high efficiency in balancing, a modular design, and the possibility of transferring energy not only between adjacent cells but between all of them. The main disadvantage is related to the balancing process since the energy is only transferred to the cell with the lowest voltage in the second part of the period [36]. In addition, it requires more hardware, specifically diodes, PWM channels, and voltage sensors.…”

Desain Penyeimbangan Sel Baterai Lithium-Ion dengan Teknik Cell-to-Cell Charging Mode pada Battery Management System (BMS)

“…Cara ini menimbulkan efek panas pada baterai, sifat dari teknik ini energi terbuang dalam bentuk panas karena hanya sebagian sel yang terisi penuh. Active balancing bekerja dengan cara mengambil muatan dari sel yang muatannya paling banyak dan ditransfer ke sel yang muatan energinya paling sedikit, sehingga muatan energi pada sel yang ada didalam battery pack persis sama sifat dari teknik ini energi teralirkan antara sel, sehingga kondisi antar sel seimbang dan tidak menghasilkan panas [5][11]…”

Statistical Battery Models and Variation-Aware Battery Management

“…However, this simple termination method sacrifice the capacity of larger-capacity cells to protect the smaller-capacity cells. Another approach tries to steering each cell current by adding switches and resistors, which is called current shunting or resistor bleeding [11,12]. Charge redistribution or energy shuttling method utilizes external energy storage devices (usually capacitors) to transfer the energy among cells to balance the cells.…”