Comparison of Active Battery Balancing Systems

Abstract

A quantitative model-based comparison of 10 active balancing circuits is presented for equalizing imbalanced cell energies of lithium-ion batteries. A mean current model approach is introduced for active balancing to describe energy transfers between battery cells for long charge/discharge operation. A Thévenin model for 96 battery cells is used as a subsystem of a mid-size electric vehicle. In quasi-static simulations, FTP75 driving cycles are continuously repeated until the first cell is discharged from initial full charge. Simulation results are compared for cases of new and aged cells with different capacity distributions concerning equalization speeds and final differences of cell energy.

MATLAB/Simulink modelling and simulation of 9-level cascaded h-bridge multilevel inverter with mismatched DC sources

“…In practice, battery characteristics such as internal resistance and self-discharge rate are different among units [7][8][9][10]. Consequently, for battery powered H-bridge cells, the voltages among batteries used as DC voltage sources are mismatched.…”

A Modular Cell Balancer Based on Multi-Winding Transformer and Switched-Capacitor Circuits for a Series-Connected Battery String in Electric Vehicles

“…Recently, the cell balancing methods have been introduced [10][11][12][13][14][15][16][17][18][19][20] and reviewed [7,8,[21][22][23], as represented in Figure 1. There are two main ways to equalize a battery cell, which are passive and active methods [8,22].…”

“…The MWT-based balancing circuit was improved by applying forward-flyback conversion [23] to balance the cells. The buck-boost converter-based cell balancing, which reduces switching loss to obtain high efficiency, is applied to EVs and HEVs [12,23,26]. However, this balancing technique requires an intelligent control and a large number of switches, resulting in relative complexity and high cost.…”

“…Nevertheless, this circuit has the complexity of fabricating MWT, a limited number of windings due to the parameter matching for the turns ratio, and leakage inductance, especially for a large number of cells. The MWT-based balancing circuit was improved by applying forward-flyback conversion [23] to balance the cells. The buck-boost converter-based cell balancing, which reduces switching loss to obtain high efficiency, is applied to EVs and HEVs [12,23,26].…”

A comparative study of battery balancing strategies for different battery operation processes

“…Among the literature, most papers focus on battery balancing circuit topologies [2][3][4][5][6][7] and balancing algorithms [1,[5][6][7][8][9][10][11][12][13][14]. The battery balancing circuit topologies reported in [2][3][4][5][6][7] mainly include resistor bleeding (passive balance), cell to cell, cell to pack, pack to cell and cell to pack to cell, and their advantage and disadvantage were presented in detail. According to the literature [1,[5][6][7][8][9][10][11][12][13][14], the battery balancing algorithms can be mainly divided into two categories: voltage-based balancing algorithm and SOC-based balancing algorithm.…”