A decoupled series compensator for voltage regulation and harmonic compensation

This paper presents a new power converter topology for the series VAr compensation of AC power systems. The scheme employs a multi-step inverter for compensation at fundamental frequency and a PWM inverter for harmonic compensation. The inverters are decoupled in such a manner that the high-frequency harmonic compensation module uses an inverter of low power rating, while the slow-switching fundamental frequency compensation module supports most of the stresses. This decoupled topology is expected to result in a significant reduction in cost and losses associated with active VAr compensators for high-power applications. The principle of operation along with the control strategy are described. Simulation results are presented to demonstrate the performance of the proposed system.