This paper presents the power factor control of a permanent magnet synchronous wind generator (PMSG) wind turbine using a phase voltage-oriented control (PVOC) scheme, which is different from the conventional rotor flux-oriented control (RFOC) method and without using a rotor position sensor or sensorless estimator. The proposed control system is operated in two separately synchronously rotating d-q frames. One is for a phase-locked loop (PLL) and the other is for the PVOC current control loop. A PI controller functioned as a low-pass filter in the PLL loop is designed for extracting the phase voltage angle for the coordinate transformation between the stationary α-β frame and the synchronously rotating d-q frame in the PVOC control loop. The d-q modeling of the PMSG with the three-phase voltage vector aligned on the d-axis is then derived and based on which an another PI controller followed by decoupling control is designed, so that the three-phase currents are in phase with the three-phase output voltages of the wind generator for unity power factor correction. The simulation results in PSIM show the performance of the proposed control system which is also experimentally verified by using a TI TMS320F28335 digital control chip.
Phase Voltage-Oriented Control of a PMSG Wind Generator for Unity Power Factor Correction