双管正激变换器的电荷平衡控制算法

为改善双管正激变换器的动态性能,利用电容电荷平衡控制原理,结合双管正激变换器在瞬态过程中的动态响应曲线,分析了如何通过控制输出电容的充电电荷和放电电荷平衡,给出了算法的理论分析和关键公式,以缩短输出电压的调节时间,减少超调量.为避免隔离变压器磁饱和,采用一种近似计算的方法解决了占空比控制信号受限的问题,扩展了电荷平衡控制算法的应用范围.最后通过所研制的实验样机进行了仿真验证和实验研究,理论分析和实验结果表明,该算法能明显地改善系统的动态响应性能.

A charge balance control algorithm of dual-transistors forward converter

An algorithm is proposed for dual-transistors forward converter (DTFC) by using the principle of charge balance control during a transient process to improve their dynamic performance. Combined with response curve,the theoretical analysis and some key equations are presented to improve the dynamic performance of the DTFC by minimizing the over/under shoot and the recovery time. In order to avoid the magnetic saturation of the transformer,an approximate method is introduced in the calculation of the optimal switching time,which can also be applied to other isolated converters when the maximum duty cycle is limited. Finally,the simulation results and the experimental results of the prototype show that,compared with the traditional voltage mode control,the proposed algorithm can significantly improve the dynamic performance of DTFCs.