Research On Energy Feedback Control Strategy Of Double PWM Converter

Compared to conventional inverters,dual PWM topology converters are controlled by IGBTs,featuring high power factor,small input current harmonics,and bidirectional flow of energy.This type of inverter is widely used in frequency-conversion timing applications such as electric cars,elevators,and elevators.This paper mainly studies the control method of energy feedback for dual PWM inverters,and focuses on its direct power-torque control strategy.Firstly,around the two states of electric and feedback,the topology of three-phase PWM rectifier(VSR)and inverter(VSI)is analyzed,and the mathematical models are studied under static coordinate system(ABC/??)and rotating coordinate system(dq).Then,the traditional control strategy of dual PWM converter is studied in detail,namely,field oriented vector control(FOC)and direct power torque control strategy based on space vector modulation(SVM-DPTC).The FOC control strategy,improved virtual flux orientation design,decoupling control structure,to realize the control of the current component of the dq coordinate system and the DC bus voltage,the simulation results show that the slow dynamic response of this scheme,and the voltage current fluctuation.The SVM-DPTC scheme is a combination of direct power control based on virtual flux based on space vector and direct torque control,directly controling the active power,reactive power,torque and flux,designing the power and virtual flux observer,power control loop control parameters.the simulation results show that the SVM-DPTC exists cheme of voltage torque and reactive component large fluctuation.Finally,aiming at the shortcomings of FOC and SVM-DPTC,the direct power-to-torque control strategy based on sliding mode variable structure(SMC-DPTC)is proposed.Sliding mode variable structure is used in place of PI controller to design the power control slip.Modular variable structure,integral sliding mode variable structure controlled by torque flux linkage,and corresponding sliding mode observer,theintroduction of power feed forward control(PF),which implements integrated control of both sides of the dual PWM frequency converter.Establishing the corresponding simulation model through MATLAB,the result shows that SMC-DPTC dynamic response is fast,the voltage fluctuation is small,the net side current is sinusoidal and the system is stable.