A self-adaptive active damping control method for a three-phase current source pwm rectifier

Abstract

An adaptive active damping control method for a three-phase current-type PWM rectifier includes the following steps of 1, establishing a parameter adjustable model based on a model reference adaptiveidentification principle; 2, sampling and reconstructing a critical voltage and current signal; 3, establishing a value optimization function; 4, obtaining an adjustable model adaptive adjustment lawaccording to the value optimization function and an optimization purpose; 5, designing the optimal virtual resistance of an LC filter based on parameter online identification; and 6, performing adaptive active damping control based on the parameter online identification.

Description

technical field [0001] The invention relates to an adaptive active damping control method of a three-phase current type PWM rectifier. Background technique [0002] The three-phase current-mode PWM rectifier has the characteristics of adjustable input power factor, four-quadrant operation, convenient current control, and step-down, making it widely used in superconducting magnetic energy storage, battery pack charging, new UPS and other occasions. However, in these occasions, the three-phase current-source PWM rectifier usually operates at high load for a long time. This long-term high-load operating condition will continue to exert electrical stress on the inductance and capacitance of the grid-connected filter, which will cause inductance and capacitance over time. The aging of the inductance and capacitance will cause a certain degree of parameter drift and even cause failure. This not only seriously affects the operational reliability and stability of the PWM rectifier,...

AI Technical Summary

Problems solved by technology

[0004] Existing active damping technology, such as patent 201310005770.0, based on the closed-loop control of the DC side of the current source rectifier, proposes an active damping control method that realizes virtual resistance through the feedback control of the AC volume on the AC side, which can effectively Suppresses the resonance of the inductor-capacitor filter on the AC side, and reduces the total harmonic distortion rate of the grid-connected current. At the same time, the patent also points out that the control performance of the closed-loop control scheme for damping the AC side depends on the system parameters strong, sensitive to parameter changes, and complex to implement, and the patent does not give a corresponding solution

Because the dependence of the system control performance on the system parameters shows that the virtual resistance method is designed in combination with the filter parameters, and its value has certain requirements. Taking the virtual resistance connected in parallel with a capacitor as an example, if the value of the virtual resistance is too large, the resonance peak will be affected Insufficient inhibition

If the value of the virtual resistance is too small, it will affect the low frequency characteristics of the filter

In actual operation, the inductance and capacitance of the filter will produce unpredictable parameter drift with its own aging state and changes in the working environment. Therefore, if the previously designed fixed virtual resistance value is still used, the control performance and resonance suppression effect will be deteriorated.

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