Single-current feedback control method of three-phase LCL (lower control limit) filtering type PWM (pulse-width modulation) rectifier

Abstract

The invention discloses a single-current feedback control method of a three-phase LCL filtering type PWM rectifier. Aiming at a conventional double-current feedback control active damping method, all that is required is to detect a current value on one side of a PWM rectification net, and a capacitance current is not required to be sampled, so that additional sensors are reduced, the reliability of a system is improved, and the hardware cost is reduced; a feedback coefficient of the current on one side of the net is adjusted in real time, so that the system damping is increased, and a resonance peak of an LCL filter is restrained; and a feedforward network voltage is introduced, and an input current on one side of the net is subjected to power decoupling control, so that the dynamic property of the system is further improved. The three-phase PWM rectifier has the advantages of high power factor, high response speed, high reliability, relatively simple design and the like.

Description

technical field [0001] The invention relates to the field of PWM rectification control, in particular to a single-current feedback control method for an LCL network side filter type three-phase PWM rectifier. Background technique [0002] Rectifiers account for a large proportion of the entire power electronic device, and most DC power sources need to be obtained through AC power rectification. However, the conventional diode rectification or phase-controlled rectification has the characteristics of low power factor and serious distortion of the input side current on the AC side, which brings serious harmonic pollution to the large power grid. The rectifier with high power factor has the characteristics of energy feedback, high power factor, and sinusoidal current waveform on the AC input side. However, the rectifier unit is connected to the large power grid with an LC filter, and the attenuation effect on high-order harmonics is not obvious. And the value of inductance is ...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is to provide a single current feedback control method for a three-phase LCL filter type PWM rectifier for the deficiencies in the prior art, so as to solve the problem that the current three-phase LCL type rectifier needs additional sensors and the connection of sampling devices for capacitive current The method and circuit structure are complicated, the design cost is high, and the grid side current harmonics are large, etc.

Images