The minimum coupling model control of grid-side three-phase PWM rectifiers

Three-phase voltage-type PWM rectifier using virtual grid-flux oriented method has good effects on harmonics and interference, but fails to fundamentally solve the cross-coupling problem of d, q axis currents. Thus, the virtual stator-flux concept was introduced, and the minimum coupling model control strategy of three-phase PWM rectifiers was proposed as well. The mathematical model of three-phase PWM rectifiers using virtual stator-flux orientation was established compared with those using the traditional virtual grid flux orientations. Direct-current control and power-factor control based on virtual stator-flux orientation were brought in. Meanwhile, the frequency adaptive observation model of the virtual stator flux was built to ensure the effective implementation of control strategies. The simulation and experimental results show the effectiveness of the proposed control schemes, which have excellent static and dynamic performance compared to the traditional virtual grid-flux oriented methods. The proposed strategy can realize decoupling control in steady and weaken the coupling effectiveness of dynamic process. © 2015, The editorial office of Transaction of China Electrotechnical Society. All right reserved.