Implementation of current source inverter for power line conditioning

A current source inverter (CSI) designed to operate as a power line conditioner (PLC) is presented. Only six power switches are required for the CSI. A 5 kVA test model of the CSI has been built using insulated gate bipolar transistors (IGBTs) controlled by a digital signal processor (DSP). To determine system performance, experimental results are compared with computer simulations of an innovative adaptive frequency domain control for pulse width modulated (PWM) switching of the CSI. The adaptive frequency domain control algorithm performs quite well in both steady-state and transient conditions. The steady-state distortion factor of the line current is reduced from 28% to 5% or less. The displacement power factor is corrected from 0.5 lagging to unity. Single cycle PLC response time to a step change in load is demonstrated