改进型有源滤波器滞环电流控制方法

Improved hysteresis circle current control method for active power filter

并联有源滤波器的变环宽滞环电流控制方法可根据电流幅值的变化实时调整滞环宽度,在保证参考电流跟踪精度的前提下,有效控制了逆变器的开关频率。对传统的变环宽滞环电流控制方法进行改进:增加环宽微调环节,当逆变器开关频率较低时,给已计算出的环宽值加入一个负的微调量,使环宽值减小。Matlab仿真结果表明,采用改进型变环宽滞环电流控制方法对并联有源滤波器谐波电流进行跟踪补偿时,系统总谐波畸变率为1.80%,小于采用传统变环宽滞环电流控制方法时的总谐波畸变率,且逆变器实际开关频率更加接近设定值。

Hysteresis circle current control method with variable circle width of shunt active powerfilter not only ensures tracking accuracy of reference current, but controls switching frequency of inverter effectively through adjusting hysteresis circle width real-timely according to current amplitude. Traditional hysteresis circle current control method with variable circle width was improved through adding a fine- tuning link of circle width. When switching frequency of the inverter is low, calculated circle width value is reduced by adding a negative fine-tuning value. The Matlab simulation results show that total harmoic distortion of the system is 1. 80% when harmonic current is tracked and compensated by use of the improved method, which is less than the value by use of the traditional method, and actual switching frequency of the inverter is more close to set value.