一种谐振型混合调制的电流型高增益双向变换器

为减小双向变换器低压侧电流纹波,改善变换器硬开关现象,降低其闭环系统设计的复杂程度,提出一种谐振型混合调制的电流型高增益双向变换器。该变换器在低压侧全桥桥臂中点加入2个交错并联的Boost电感,在增加变换器增益的同时可减小变换器低压侧电流纹波,高压侧为倍压整流电路,进一步增加了变换器增益,同时利用变压器漏感与谐振电容谐振创造了高压侧开关管ZCS的条件。该变换器正反向均采用PWM+PFM混合调制控制,通过改变占空比调节输出电压,调节开关频率实现高压侧开关管的ZCS,采用该控制方案降低了变换器闭环系统设计的复杂程度,并可减小高压侧开关管的关断损耗。搭建一台600 W试验样机,进行正反向实验,验证所提方案的有效性。

A CURRENT FED RESONANT HIGH STEP-UP BIDIRECTIONAL CONVERTER BASED ON RESONANT HYBIRD MODULATION

In order to reduce the current ripple on the low-voltage side of the bidirectional converter,improve the hard switching phenomenon of the converter and reduce the complexity of the closed-loop system design,a current fed resonant high step-up converter based on resonant hybrid modulation is proposed in this paper.Two Boost input inductors for the converter are interleaved in the bridge arms in low voltage side to reduce the low side current ripple and increase voltage gain.A voltage double rectifier circuit is added on the high voltage side to increase converter gain.The ZCS for all switches in the high-voltage side can be realized by the resonance of the leakage inductance of the transformer and the resonant capacitor.PWM+PFM hybrid modulation control is adopted by the proposed converter in both forward and backward mode.The output voltage is adjusted by changing duty ratio,and switching frequency is adjusted to realize the ZCS of the switches in high-voltage side.The complexity of the closed-loop system designing for the converter is reduced by using proposed control method.The losses of the switches in high-voltage side can be reduced.A 600 W prototype was built in this paper.The forward and backward experiments were carried out to verify the effectiveness of the proposed scheme.