A 3-PHASE ACTIVE POWER FILTER OPERATING WITH FIXED SWITCHING FREQUENCY FOR REACTIVE POWER AND CURRENT HARMONIC COMPENSATION

The performance and dynamic characteristics of a three-phase active po wer filter operating with fixed switching frequency is presented and a nalyzed in this paper, The proposed scheme employs a PWM voltage-sourc e inverter and has two important characteristics. First, it operates w ith fixed switching frequency, and second, it can compensate the react ive power and the current harmonic components of nonlinear loads. Reac tive power compensation is achieved without sensing and computing the reactive component of the load current, thus simplifying the control s ystem. Current harmonic compensation is done in time domain. The princ iples of operation of the proposed active power filter along with the design criteria of the power and control circuit components are discus sed in detail, Finally, experimental results obtained from a 5-kVA pro totype confirm the feasibility and the features of the proposed system .