A new control method of LCL three-phase shunt active power filter

Abstract

The invention discloses a novel control method of an LCL type three-phase shunt active power filter, which constructs a system of an active power filter with LCL filter based on an active damping optimization control method of a single-network-side inductance current feedback and a current tracking control method of a novel generalized integrator. A high-pass filter is added to the feedback loop to optimize the parameters, which overcomes the disadvantageous influence of the existing active damping method on the stability of the system in the fundamental domain. At that same resonant frequency, first-order generalized integrator with opposite phase order, As such, that novel generalize integrator realizes infinite gain only at the positive sequence resonant frequency or only at the negative sequence resonant frequency, The novel generalized integrator has the characteristics of selective compensation for positive and negative sequence signals with the same frequency, and can distributedifferent gains, reduce the complexity of control algorithm, improve the computational efficiency, solve the problem of harmonic compensation under the condition of unbalanced power network and load,and improve the compensation performance and flexibility of application.

Description

technical field [0001] The invention relates to the technical field of three-phase parallel active power filters, in particular to a novel control method for an LCL type three-phase parallel active power filter. Background technique [0002] With the widespread application of a large number of power electronic devices in power systems, the problem of harmonic distortion caused by nonlinear loads is becoming more and more serious. Harmonic governance is paid more and more attention by people. Compared with passive filters, Active Power Filter (APF) has the characteristics of good filtering characteristics, small size, flexible application, and is not easy to generate resonance in the power grid. It has become one of the effective means of harmonic control in the power grid. [0003] With the development of semiconductor technology, APF is developing towards the direction of large capacity and high power density. Grid-connected output filter has become one of the key factors...

AI Technical Summary

Problems solved by technology

Hysteresis control has fast response, does not use carrier, and does not contain specific harmonics, but the hysteresis bandwidth is not easy to set, and the switching frequency of power devices is not fixed; deadbeat control has the characteristics of fast dynamic response, but it is highly dependent on system parameters , poor anti-interference ability; PI control is a mature control method widely used, which can realize no-steady-state error adjustment for DC signals, but for high-frequency AC components such as APF harmonic currents, the tracking effect is not good

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