Research On Direct Power Control Of Three-Phase Dual PWM Converter

With the rapid development of global economy, the energy is shortage, new energy development and energy saving technology has become a hot technology field, attention by the majority of scholars. Dual PWM converter has a good application prospect in fields such as new energy, as it has advantages of unity power factor, low harmonic distortion of AC side current, bidirectional power flow, etc. The main contents are as following:The mathematical model of three-phase PWM rectifier is established according to instantaneous reactive power theory in two phase static frame. And on this basis, To improve the deficiency of direct power control algorithm of the traditional PWM rectifier, the paper puts forward a new predictive direct power control algorithm without dynamic sector. And then the paper proposed a predictive power control method of virtual flux without voltage sensor. Designed a low pass filter model to solve the problems with the integration of initial value and eliminating DC bias. Results of simulation prove the validity of this method.To the PWM converter of motor side, proposed a direct power control based on the theory of instantaneous reactive power control algorithm. Select the desired switching vector in the motor side PWM converter power according to the error. Achieve unity power factor, reduce electric extra loss of energy.Power flow situation of dual PWM converter is analyzed. a load power feed-forward control strategy is proposed to realize the coordination of VF-P-DPC strategy of PWM rectifier and DPC method of PWM inverter through making predictive instantaneous active power component in DPC method as load power, achieve coordinated control of dual PWM converter.Finally, Comparative experiments are carried out and experimental results show that dual PWM converter has a better performance and application prospect. Verify the correctness of the theory.