Phase compensation device and method based on Vienna rectifier.

Abstract

The invention discloses a phase compensation device and method based on a Vienna rectifier. The device comprises the Vienna rectifier, a digital processing control module and a driving circuit. The method comprises the steps that the three-phase voltage at the alternating-current side is sampled, and compensation coefficients of all phases are calculated; the three-phase current at the alternating-current side is sampled, and three-phase compensation signals are calculated; the voltages of an upper capacitor and a lower capacitor on the direct-current side are sampled, and the output signals of a neutral-point voltage control unit are calculated; the three-phase current at the alternating-current side, the output signals of the neutral-point voltage control unit and the three-phase compensation signals are added to obtain a modulation signal; the voltages of the upper capacitor and the lower capacitor on the direct-current side are sampled, the amplitude of the carrier signal is calculated, and a triangular carrier signal is obtained; and the modulation signal and the triangular carrier signal are processed to obtain a pulse width modulation signal, and a Vienna rectifier switch tube is driven to work. The method is low in hardware cost, accurate in control and wide in application range, and the problem of phase shifting between the alternating-current side voltage and the current of the Vienna rectifier when the input is unbalanced is effectively solved, and the total harmonic distortion rate of the alternating-current side current is lowered.

Description

technical field [0001] The invention belongs to the technical field of power electronic conversion, in particular to a phase compensation device and method based on a Vienna rectifier. Background technique [0002] The Vienna rectifier is a three-level topology, which has the advantages of low voltage stress of the power switch, small number of power switches, high power density, low input current harmonic content, and good adaptability to various types of PFC control methods. , so it has been widely used in the research of power factor correction technology. At the same time, in recent years, many literatures have carried out in-depth research on the three-phase PFC rectifier based on single-cycle control. The controller of single-cycle control generally does not need a multiplier, and only needs to perform simple integration and addition and subtraction of the input current, and Direct comparison of the reference signal can realize the control waveform of the switching el...

AI Technical Summary

Problems solved by technology

The traditional single-cycle control can achieve the same phase of input current and input voltage under the condition of input balance, but under the condition of input imbalance, the use of traditional single-cycle control will cause a phase shift between the input current and input voltage, which cannot achieve unity power factor control The goal

[0003] As a special phenomenon in the rectifier power supply system, the unbalanced three-phase input AC voltage will affect the normal operation of the rectifier power supply system, for example, it will cause low-frequency ripples in the output DC voltage, low-frequency ripples in the input power, and distortion of the input current.

Aiming at the problem of three-phase input AC voltage unbalance and phase compensation, literature 1 (Jin Aijuan, Li Hangtian, Li Shaolong. An improved control strategy of the one-cycle control three-phase PFC rectifier under unbalanced conditions [J]. Transactions of China Electrontechnical Society, 2006,21(7):115-121.) The traditional single-cycle control is improved by introducing the concept of asymmetrical coefficient, and the sampling value of the input current of each phase is adjusted through the asymmetrical coefficient, so as to realize the relationship between the current of each phase and the respective voltage In-phase, improving input current quality, but this solution requires complex mathematical operations and can only be controlled digitally

Document 2 (Wei Zheng. Research on Aeronautical Medium Frequency High Power Factor Rectifier [D]. Nanjing University of Aeronautics and Astronautics, 2014.) By adding a resonant controller after the voltage regulator to suppress the DC side fluctuation caused by unbalanced voltage, but the input current There is still a phase shift with the input voltage

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