Implementation method of inverse system controller of active power filter

Abstract

The invention discloses an implementation method of an inverse system controller of an active power filter, which comprises the following steps: establishing a mathematical model of parallel main circuits of the active power filter under a d-q coordinate system; decoupling two variables of current components of offset current under the d-q coordinate system; constructing a pseudo-linear system after the decoupling so as to ensure that an optimal control signal joins into the pseudo-linear system to obtain an optimal inverse system control matrix; and finally, obtaining a reference value of the offset current by carrying out coordinate transformation on detected harmonic current. The invention changes a control policy of a conventional active power filter, carries out pseudo-linear processing on a nonlinear coupled system, directly works out a switching coefficient of the main circuits during working and the working modes of devices of the main circuits, has visualized physical conception, simple mathematical deduction, small operand and higher control precision and can guarantee the energy exchange of direct current and alternating current when a load is suddenly changed.

Description

technical field [0001] The invention relates to a feedback linearization control of an active power filter, in particular to a method for realizing an inverse system controller of an active power filter. Background technique [0002] With the development of power electronics technology, there are more and more nonlinear loads in the power system, and the voltage and current harmonics generated by the nonlinear loads seriously affect the power quality in the power transmission system. Active power filter (APF, the same below), as a new type of power electronic device for controlling harmonics in the power grid, has been rapidly developed. The basic principle is to control the APF according to the detected load harmonic current component, so that it can send out an opposite harmonic current to offset, so as to achieve the purpose of real-time compensation of harmonics. [0003] The output current of the active power filter contains high-order harmonics and transient currents,...

AI Technical Summary

Problems solved by technology

Hysteresis tracking control has high precision and fast response, but the switching frequency is unstable, which is easy to cause pulse current and switching noise; triangular wave comparison control has constant switching frequency, high device safety, but slow response and low precision

In addition, the deadbeat control strategy has the advantages of strict mathematical derivation, no overshoot in tracking, and good dynamic performance, but the control effect is not good under load disturbance and nonlinear load.

As a non-linear control method, one-cycle control has duality of modulation and control at the same time. It achieves the purpose of tracking command signals through reset switches, integrators, trigger circuits, and comparators. Poor suppression of load disturbance

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