An improved control strategy for the charge equalization of lithium ion battery

Abstract

Charge equalization is important to reduce the damage and improve the lifetime of the battery. An improved control strategy of the equalization circuit is presented in this paper. The over-equalization technique has been utilized to shorten the equalization time about 25%. The hysteresis control is also been used to improve the robustness of the system. The simulation and prototype experimental results have proved the validity and reliability of the proposed control strategy.

Lithium-Ion Battery Cells Voltage Equalization Using Optimized Circuit Parameters and Control Strategy

“…Several control strategies have been proposed and studied [9]- [15]. Most of them are based on voltage difference and frequency conversion control: hysteresis voltage difference control [9], fuzzy logic voltage difference control [10]- [14] and fuzzy-PI voltage difference control [15].…”

A high efficiency isolated bidirectional equalizer for Lithium-ion battery string

“…When the voltage is inconsistent, equalization activated. When battery voltage reaches the same, equalization comes to an end [7]. But affected by the hysteretic characteristic of Lithium-ion battery during charging and discharging, SOC differences still exist even when battery voltage are same [8].…”

Balancing Control Strategy for Li-Ion Batteries String Based on Dynamic Balanced Point

“…In considerations of energy consumption and transformation, they can be divided into dissipative balancing circuits [4] or non-dissipative balancing circuits [5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Dissipative balancing circuits violate the future trend of energy-saving, although it is practical with simple topologic and convenient control strategy.…”

“…Dissipative balancing circuits violate the future trend of energy-saving, although it is practical with simple topologic and convenient control strategy. According to the charge transfer structure, non-dissipative balancing circuits can be classified into three methods: pack-to-cell balancing methods [6][7][8][9][10][11], a direct cell-to-cell method [12][13][14] and an adjacent cell-to-cell method [15][16][17]. The pack-to-cell balancing methods and direct cell-to-cell generally show outstanding balancing performance and speed due to direct charge transfer.…”

“…Nowadays, a lot of equalization structures and balancing strategies have been proposed [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18], and summarized in [2,15]. In considerations of energy consumption and transformation, they can be divided into dissipative balancing circuits [4] or non-dissipative balancing circuits [5][6][7][8][9][10][11][12][13][14][15][16][17][18].…”