Three-phase PWM rectifier control method

Abstract

The invention provides a three-phase PWM rectifier control method which includes a direct current capacitor energy storage outer loop control method and a grid-side current inner loop control method. The method includes the steps that direct current capacitor stored energy of a rectifier is fed back as a whole, given capacitor charging power is output after calculation is finished through an energy PI adjuster, grid-side input power is obtained by adding load power to the given capacitor charging power, a given grid-side d-axis current value i*d is obtained by dividing grid-side input power by the grid-side d-axis voltage component, a given q-axis current value i*q is obtained according to the relation between given d-axis current and given q-axis current, a grid-side voltage control value ud and a grid-side voltage control value uq are obtained in sequence according to the grid-side current inner loop control method, given voltage values are obtained through feedforward and decoupling of the ud, uq and the network voltage, given phase voltage output values are obtained through Park inverse transformation and Clark inverse transformation, and switch control signals Sa, Sb and Sc used for driving a PWM rectifier bridge arm electronic switch are obtained finally through space vector pulse width modulation. By means of the method, the dynamic response performance of a three-phase PWM rectifier can be improved greatly, and the method is particularly suitable for fast charging of electric cars and other occasions having high requirements for the response performance of the three-phase PWM rectifier.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a control method for a three-phase power electronic conversion device. Background technique [0002] Traditional rectifiers are composed of diodes or thyristors. This type of rectifier has disadvantages such as high input current harmonic content, low input power factor, one-way energy transfer, and uncontrollable DC side voltage. Since the late 1980s, PWM (Pulse Width Modulation, Pulse Width Modulation) technology has been introduced into rectifier control, and this high power factor PWM rectifier technology has become a research hotspot at home and abroad. Compared with the traditional rectification technology, the voltage source PWM rectification technology has the advantages of bidirectional flow of energy, controllable DC side voltage, low input current harmonics, high power factor, etc., and truly realizes "green power conversion". It is used in active power filt...

AI Technical Summary

Problems solved by technology

Since the direct power control method often adopts the double closed-loop design of the voltage feedback outer loop and the current feedback inner loop, and uses the power hysteresis loop to select the switch table, the switching frequency is not fixed, and the changing switching frequency is not conducive to the design of the AC side reactance filter.

At the same time, due to the high sampling period, high-speed A / D converters and processors are required for data acquisition and algorithm processing, which is not convenient for system implementation.

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