The Research and Implementation of Dynamic Voltage Restorer with Power Factor Correction

The principle of the dynamic voltage restorer (DVR) to the voltage sag problem with phase angle jump is analyzed in this paper. Based on the fundamental component of steady-state equivalent circuit, the phase diagram with voltage fluctuations and phase angle jump is shown. According to instantaneous reactive power theory and the low-pass filter theory, the initial phase of the source fundamental phase voltage and phase angle jump are given. And with the optimum voltage injection angle based on minimum energy compensation, the target voltage function on which gives the appropriate compensation output voltage of DVR is determined. The simulation process and results are also offered. The harmonic current of nonlinear rectifier can generate the grid pollution and reduce the power factor when correcting. To solve this problem the paper proposes to adopt active power factor correction (APFC) circuit on the input side to reduce harmonic and improve the power factor. A prototype using digital signal processing (DSP) as the master control chip is designed and the software process is developed. Finally, the experimental results are provided to verify the rationality of the optimal voltage injection angle of series compensation based on the minimum energy control strategy.