A Simple Direct Power Control of Three-Phase PWM Rectifier using Virtual Flux Estimation

Abstract

In Direct Power Control(DPC)scheme power will be controlled by operating switching such that it will give almost unity power factor in source side and regulated DC voltage on the load side. In this project, DPC is initially simulated in Matlab/Simulink by implementing the benchmark methods proposed in the literature. These methods are classical DPC using 12 sectors proposed by Noguchi and virtual flux estimation based DPC introduced by Malinowski et al. After obtaining the expected outputs as given in the literature, the work has been extended by implementing with a proposed table for better performance. To improve the resolution of sector selection, the work has been extended to eighteen sector table based DPC. Further, both the above mentioned proposed methods are tested with and without source side voltage sensors in a simulation study. In DPC, the control of instantaneous active and reactive power is performed directly by selecting the optimum switching state of the converter. Using virtual flux estimation technique, it is possible to locate the position of voltage space vector without the voltage source side sensors. So,both active and reactive power is calculated for each switching state of the converter from the line currents and virtual flux. From the simulation results, it was confirmed that the total power factor was more than 0.94.