Current control method for three-phase voltage source type PWM rectifier

Abstract

The invention discloses a current control method for a three-phase voltage source type PWM rectifier. The current control method comprises the steps that in a static coordinate system, a dual-closed-loop vector control strategy is adopted, an alternating-current given value of the rectifier is calculated to be obtained by collecting an alternating-current side voltage, an alternating-current side current and a direct-current voltage of the rectifier, the alternating-current given value and an actual value are compared, calculated and fed into an H-infinity current regulator, an output signal of the H-infinity current regulator and a network voltage feed forward signal are added to obtain a bridge terminal voltage reference signal of the rectifier, and then a switch control signal of the rectifier is generated through PWM and used for controlling an IGBT to be switched on or off so as to achieve the electric energy conversion function. According to the current control method for the three-phase voltage source type PWM rectifier, the H-infinity current regulator is designed to be transformed to solve the H-infinity standard problem by establishing a mathematic model of the rectifier and the filter of the rectifier; due to the influence of the problems of rectifier parameter uncertainty, inherent LC oscillation and the like, a reasonable weight function is constructed to conduct optimal design on the H-infinity current regulator, the output current of the three-phase voltage source type PWM rectifier is regulated through the H-infinity current regulator, and the direct voltage and the output power of the rectifier are controlled.

Description

technical field [0001] The invention relates to a control method of an active rectification / inversion converter, in particular to a current control method of a three-phase voltage source PWM rectifier with an inductance-capacitance-inductance (LCL) filter. Background technique [0002] At present, power electronic rectifiers based on fully controlled switching devices and pulse width modulation (PWM) technology have been widely used, and the system capacity is still increasing. Its application fields include uninterruptible power supply (UPS), active power filter (APF), static synchronous var compensator (STATCOM), dynamic voltage restorer (DVR), flexible high-voltage direct current transmission (VSC-HVDC), etc., these Basic prototypes of equipment often employ voltage source rectifiers. [0003] The control of the three-phase rectifier generally adopts double-closed-loop vector control. Using coordinate transformation technology, in a synchronous rotating coordinate syste...

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Problems solved by technology

Affected by the uncertainty of rectifier parameters, etc., this kind of trade-off generally requires on-site debugging based on experience, which is time-consuming and laborious

[0006] M. Malinowski used variable The capacitor voltage is estimated by the rectifier side current and the control voltage, thereby reducing the number of sensors, but because the current differential link is used in the control algorithm, it is easy to introduce interference, and even cause the rectifier to run unstable

[0007] The above methods are to study the control law of the rectifier through the analytical method, and the control parameters depend on the actual experience, which often cannot guarantee that the designed controller is optimal.

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