POWER QUALITY COMPENSATION SYSTEM AND CONTROL METHOD WITH BUS VOLTAGE AND CURRENT PEAK CONTROL

A power quality compensation system has the functions of controlling the bus voltage and the current peak value. A first instruction current under control of a first peak current processing unit is lower than or equal to a first current threshold value. A second peak current processing unit outputs a second PWM driving signal according to a sampled current and a second current threshold value. A third peak current processing unit outputs a third PWM driving signal according to the sampled current and a third current threshold value. A conversion unit is operated according to the PWM driving signals. Moreover, the first current threshold value is adjusted in real time according to the comparing result of the sample current and the first current threshold value and the comparing result of the real DC bus voltage and the reference DC bus voltage.