在传统单相功率因数校正器(PFC)中,当IGBT导通时,升压电感输出端对地之间电压接近零,单相电源交流通过电感短路,电感电流上升而储能。当IGBT关断时,电感续流,向电解电容释放能量。通过控制IGBT的占空比规律,获得网侧单位功率因数和稳定直流输出电压。因此提出一种当IGBT导通时,升压电感输出端对地之间电压为负电压的两电平PFC方案,进而提出一种两级交错PFC、一种单相有源电力滤波器和一种升降压AC-DC变换器方案。由于采用负电压短路,可以减少交越失真,获得更好的功率因数校正效果。在简要理论分析的基础上,利用MATLAB/IMULINK进行了仿真分析,所得结果验证了所提方案的正确性。
In the traditional single-phase power factor corrector( PFC),when the IGBT turns on,the voltage between the output of the boost inductor and the ground is close to the zero-voltage. The single-phase AC power charges when the inductor is in short circuit and the inductor current rises. When the IGBT is turned off,the inductor freewheels and releases energy to the electrolytic capacitor. By controlling the duty cycle of the IGBT,we can obtain unity power factor of the network side and stable DC output voltage. This paper introduces a two-level PFC plan: when the IGBT turns on,the voltage between the output of the boost inductor and the ground is negative. Furthermore,it proposes a two-stage interleaved PFC,a single-phase active power filter and a Buck-Boost AC-DC converter. Short circuiting of negative voltage reduces crossover distortion,and a better correction of power factor is achieved. On the basis of a brief theoretical analysis,MATLAB / IMULINK simulation analysis is made,and the results verify the correctness of the proposed scheme.