A multi-function three-level dynamic voltage corrector with wide correction range and short circuit fault isolation

Abstract

The dynamic sag corrector is used at the sensitive loads terminal in order to avoid the grid voltage sag. This paper focuses on both the correction of grid voltage swell/sag in large range and the quality of compensated voltage. A wide correction range dynamic voltage corrector is proposed for solving above problems with small cost. It possesses dual functions of both the wide range voltage correction and the short circuit fault isolation. The operation principle and the voltage correction range are analyzed. The increase of the DC bus voltage broadens the voltage sag correction range, while the realization of the voltage swell correction benefits from the bidirectional energy flow. The output inductor current control completes both the current limitation and the fault isolation at the moment of the load short circuit. The experimental results verify the validity of the theoretical analysis. The proposed dynamic voltage corrector is suitable for the voltage stabilization of ground power unit, production lines or aerospace equipment under the centralized power supply. It has the characteristics of small size, light weight, good dynamic performance and high quality of output waveform.