Extended ZVS Modulation for a Dual Cell Link in the Demand of Faster Balancing

摘要

The novel balancing circuit integrating auxiliary power modules for xEV applications is enhanced, in terms of light load performance, balancing speed, and current ripple of the inductive component. The improvements are realized by varying the operating frequency of the power switches within a reasonable range. The soft-switching range as a function of frequency, phase shift and the initial leakage inductance current is derived in detail. Faster balancing speed is achieved with little introduced losses. The power regulation strategy is also given to ensure delivering desired power designed for nominal frequency. All the concepts are verified in the high-fidelity converter model and approved to improve the balancing speed by 10 % at 110 % nominal frequency. 50 % power range increased can be achieved at 120 % nominal frequency. Higher frequencies will ensure more features, such as decreased current ripple.