Three-phase voltage-type PWM rectifiers with inner power loop and outer voltage square loop

The independent control of instantaneous active power and reactive power is obtained based on the power control mathematical model of voltage-type PWM rectifiers in synchronous dq coordinates and power feedforward decoupling. In order to overcome the defects of current control strategy, direct power control strategy and nonlinear control strategy for voltage-type PWM rectifiers, a new control strategy using inner power loop and outer voltage square loop is proposed. Good tracking properties of dc voltage and power of voltage-type PWM rectifiers are obtained by using the new strategy. The system using the new strategy has many advantages, such as fast response, good stability, load disturbance resistance, and simpler structure, The design method for a system controller is given. The new control strategy is proved feasible by Simulink simulation under nominal load and load disturbance.