Sliding mode proportion resonance control method based on three-phase Vienna rectifier

Abstract

A sliding mode proportion resonance control method based on a three-phase Vienna rectifier is disclosed. The method is characterized by according to a Kirchhoff law and the topological structure of the three-phase Vienna rectifier, deducing a three-phase rectifier circuit equation; collecting the voltages Uc1 and Uc2 of the upper and lower capacitors of a direct current side, alternating current side currents ia, ib and ic and voltages Ua, Ub and Uc, adding the collected voltages Uc1 and Uc2 of the upper and lower capacitors of the direct current side and acquiring a total voltage Udc, using the difference value of the Udc and a direct current side voltage reference value Udcref to acquire a current reference value idref through a sliding mode controller, introducing into a formula: iqref=0, through 2s/2r conversion, acquiring i alpha and i beta, carrying out 3s/2r conversion on the alternating current side currents so as to acquire actual current values i alpharef and i betaref, then,subtracting the i alpharef and the i alpha, and the i betaref and the i beta, through proportion resonance control, acquiring usalpha and usbeta, and through the voltages Ua, Ub and Uc, acquiring theangle theta of a phase-locked loop; and introducing the usalpha, usbeta, a direct current side voltage udc, the alternating current side currents ia, ib and ic, and a middle point voltage signal intoa controller, and finally acquiring a Vienna rectifier switch on-off signal. In the invention, the robustness and the dynamic performance of the Vienna rectifier are increased, the reaction speed ofthe Vienna rectifier is increased too, a direct current side voltage fluctuation is reduced, simultaneously a good anti-load-disturbance capability is possessed.

Description

Technical field [0001] The invention belongs to the field of Vienna rectifiers, in particular to a sliding mode proportional resonance control method based on a three-phase Vienna rectifier. Background technique [0002] The Vienna rectifier is an excellent three-level rectifier. Compared with the traditional three-level PWM rectifier, it saves the number of switching devices. The switching device withstands voltage is half of the output voltage, reducing device stress, no need to set the driving dead time, control algorithm Relatively simple and other advantages, it has become a hot research direction of rectifiers, and Vienna rectifiers can better control grid harmonic pollution, improve power quality, reduce harmonic content in the grid, and improve power factors. In practical applications, the double closed loop of Vienna rectifier generally adopts PI control strategy, but PI control is difficult to achieve AC signal tracking without static error, and the dynamic response spe...

AI Technical Summary

Problems solved by technology

Although this strategy can make the adjustment of current relatively simple, the system needs to increase the complexity of PI regulator parameter setting and control system design

And for the Vienna rectifier, the conventional dual PI control is used, the system dynamics are relatively poor, and the contradiction between the voltage overshoot and the speed and accuracy is also prominent, and it is difficult to achieve the ideal control effect

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