Using AC-fed PWM converters as instantaneous reactive power compensators

A general control method that fully utilizes the inherent capability of AC-fed PWM converters to compensate for reactive and harmonic currents adsorbed by other loads is presented. For this purpose, suitable definitions of instantaneous active and reactive current and power terms are introduced. Optimum modulation laws are then derived according to a general control theory valid for PWM multiconverter systems which also results in maximum system efficiency. Simulated results demonstrate the capabilities of the proposed compensation method, which can also be implemented in existing systems as only modifications of the control section are needed