Modified one-cycle controlled load compensator

Abstract

Load compensators based on one-cycle control (OCC) exhibit instability in current control when real power involved with the load to be compensated is low. Instability in current control is also encountered when the load to be compensated is of regenerative type. A modified OCC-based load compensator is proposed. A fictitious current component in phase with the utility voltage is synthesised. The sum of this current component and the source current is compared with the saw-tooth waveform to generate the gating pulses for the switches. This modification significantly improves the stability margin of its operation so that it can compensate loads having low real current component as well as can compensate regenerative type of loads. Detailed simulation studies are carried out to verify the effectiveness of the proposed scheme. To validate the viability of the scheme, detailed experimental studies are carried out on a 2 kVA laboratory prototype developed for the purpose.