Double PWM coordinated control based on model predictive algorithm and power compensation

Abstract

With analysis on double PWM structure though system's energy flow theory, active power and reactive power of rectifier are controlled by model predictive algorithm. System adopts the method of combine dynamic power's compensation with static power's compensation for system power in order to reduce system power error. A new power compensation algorithm is proposed to designs a new controller to replace PI controller of system's voltage loop, which can restrain fluctuation of DC bus voltage when load power suddenly varies and reduces DC-link's capacity of capacitance. As for inverter side, the system uses the method of rotor flux linkage oriented to control three phase asynchronous motor. Results of simulation can show that, system can realise the smallest tracking error of active power and reactive power by model predictive control, and restrain fluctuation of DC bus when load power suddenly changes. As the same time, the gird current's waveform is well.