软开关双向DC-DC变换器控制模型

Bidirectional DC / DC converter control model analysis based on super capacitor

针对在大功率能量存储场合适用的非隔离双向DC-DC变换器一般存在着开关损耗大、断续工作时寄生振荡等问题,研究了非隔离双向DC-DC变换器的基本原理,为了提高系统的功率密度减少系统损耗,半桥变换器的开关管互补导通,并工作在电感电流断续过零状态以实现软开关。对采用超级电容的双向变换器进行了定量分析,分析并计算了主电路电感与电容参数。同时,通过对双向变换器的控制模型的分析,对超级电容采用恒流充电、恒流恒压放电的策略,实现了双向DC-DC变换器双向工作的稳定。在以上理论分析的基础上,搭建了实验样机进行实验验证,仿真和实验结果验证了本文控制模型分析的正确性。

Non-isolated bi-directional DC-DC converter applied for high-power energy storage has prob- lems of large switching losses and intermittent problems when working parasitic oscillation. The basic principle of non-isolated bi-directional DC-DC converter was analyzed and studied, in order to improve the power density of the system and to reduce the system losses, the switching tube in half-bridge convert- er work in complementary conduction, and work in the intermittent state to achieve soft switching. The value of the conductor and the super capacitor in the main circuit was analyzed and calculated. At the same time, by the analysis of the control model of bi-directional converter, super capacitor adopted con- stant current charging, constant current and voltage discharging strategy, to achieve the stability of the bi- directional DC-DC converter. After theoretical simulation, an experimental prototype was built as experi- mental verification. And stable operation of the experimental prototype verifes the correctness of the con- trol model analysis in this article.