Research on Signal Extraction and Control Strategy of Single-Phase PWM Rectifier in d-q Coordinate Frame

There are some AC time-varying physical quantities in single-phase PWM rectifier, as a result, it is difficult to design control system. a current inner loop-voltage outer loop control strategy is implemented by establishing the math model in d-q synchronous frame. The grid voltage contains abundant harmonics, which seriously affects the detection accuracy of the voltage phase, and the virtual component of grid-side current cannot be directly sampled, so a discrete extraction method for the fundamental component of the grid voltage without phase-locked loop is proposed. Simulation and experimental results show that under different loads, the output voltage of the rectifier can accurately follow the given, and the dynamic performance is good. The grid-side current and electromotive force maintain unit power factor operation, which proves the virtual current detection method and control strategy proposed in this paper is feasibility and correctness.