Research on Fuzzy PI Control Strategy of PWM Rectifier as an Active Current Harmonic Filter

Non-linear loads increase harmonic current of power supply, depress its power factor, and enhance power loss. In order to solve this problem, different kinds of active filtering technologies presently have been widely used in the various power circuits. Because of its complicated control structure and high cost, general active power filter is difficult to apply and popularize. Based on the control strategy of fuzzy proportional and integral (fuzzy-PI), a kind of pulse width modulation (PWM) rectifier with the type of voltage source current control (VSCC) was proposed to act as an active power filter to realize current filtering, delink voltage controlling and power factor compensating. The structure of the control system was given and a fuzzy-PI controller was designed, also the devised system was tested and evaluated by real time in an experimental device based on digital signal processor (DSP). The experimental results show that fuzzy-PI control has better dynamic and static performances than traditional PI control, also it has the merits such as simple structure and low cost