Performance Analysis of a PWM Inverter VAR Compensator

The performance pf a three-phase solid-state reactive power compensator with fast dynamic response is analyzed in this paper. The compensator consists of a three-phase pulse-width modulated voltage-source inverter connected to a self-controlled dc bus. The principal advantage of this scheme is that it can maintain a near-unity source power factor without sensing and computation of the associated reactive power component. A mathematical model for the compensator connected across a variable power factor load is derived. The frequency response is obtained for open loop operation. This allows the design of the controller. Predicted results are verified experimentally for both open and closed loop responses.