单相低纹波PWM整流器的直接功率控制

Direct Power Control for a Single-Phase Low-Ripple PWM Rectifier

传统的单相PWM整流器工作时,其直流母线电压存在较大的波动,通常需要在直流侧并联容值较大的电解电容.为了解决这一问题,采用在传统整流器直流侧并联有源辅助回路来构成单相低纹波PWM整流器以减少直流母线电压的波动.为了能在整个低纹波PWM整流器中实现直接功率控制,通过求解一个能体现有功无功跟踪能力的指标函数来实现整流回路的直接功率控制,推导辅助回路输出电流与整流回路输入功率的关系,以此来实现对辅助回路的直接功率控制.仿真结果表明:采用提出的直接功率控制策略,不仅能够极大地降低整流器直流母线纹波电压、确保整流器的单位功率因数运行,还能在辅助回路的作用下减少直流母线电压的稳定时间.

There is inevitable DC voltage fluctuate in the DC side of conventional single-phase PWM rectifiers.The commonly used technique to decrease the DC voltage fluctuate is to use a paralleling electrolytic capacitor with large capacity.In order to address the issue,a shunt active auxiliary circuit paralleled with the DC side of conventional single-phase PWM rectifiers was used to decrease the fluctuation of DC bus voltage.In order to realize direct power control in the low-ripple PWM rectifier,a direct power control strategy for the rectifier circuit was realized by solving an index function,which could reflect the ability of active and reactive power tracking.In addition,a direct power control for the auxiliary circuit was achieved by deducing the relationship between the output current of auxiliary circuit and the input power of rectifier circuit.The simulation results show that the proposed direct power control strategy can not only reduce the DC voltage fluctuate sharply and achieve a unit power factor,but also decrease the setting time of DC voltage.