Analysis and Modeling of Dual-half-brige Converter Applied in High-Voltage Battery Balancing

In battery management systems (BMSs), the conventional single-stage active balancing method has the severe problem that the overall insulation would be reduced and the balancing speed drops rapidly with the increase of battery cells. Nowadays, two-stage balancing method has been paid much more attention where each first-stage converter balances the cells' energy within a battery module, and the second-stage one balances the voltages among all battery modules. This paper focuses on the second-stage converter using dual-half-bridge DC-DC converter, and establishes a mathematical model under the composite control of phase shifting (PS) and pulse width modulation (PWM). Control scheme is designed according to the results of simulation. Experiments show that the proposed method can achieve high and steady efficiency up to 93.58%.