Diagnosis method for active power filter switching device open-circuit fault based on model reference analysis

Abstract

The invention discloses a diagnosis method for an active power filter switching device open-circuit fault based on model reference analysis. The diagnosis method includes the steps that on the basis of building an actual operation model of active power filter main circuits, a reference model is constructed; measurable active power filters in all sampling periods are used for outputting three-phase compensating currents, and voltage residual errors are generated according to reference analysis of the model; by setting a threshold value and two judgment flag bits, the residual errors are evaluated to detect whether the open-circuit fault happens on an APF switching device or not in real time; if the fault happens, the specific position where the open-circuit fault of the switching device happens is diagnosed according to the two judgment flag bits. The diagnosis method is effectively used for monitoring the active power filters on line and diagnosing faults, and electric, electronic and electric energy quality control devices such as the active power filters and reactive compensators operate reliably and safely.

Description

technical field [0001] The patent of the invention belongs to the field of active power filter fault diagnosis, and relates to an open-circuit fault diagnosis method for a three-phase three-wire active power filter switching device. Background technique [0002] With the increasing application of non-linear loads and various power electronic switching devices in modern industries, the harmonic pollution injected into the power grid is also becoming more and more serious, which brings serious hidden dangers to the efficiency of the power grid and the safe operation of other equipment. Active power filter is a kind of power conditioner that controls the harmonics of the power grid and improves the power quality. It has been widely used in metallurgy, steel, transportation, chemical industry, communication and other fields. [0003] The reliability of semiconductor switching devices is an important index to measure the reliability and safety of APF system operation. Fast and a...

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Problems solved by technology

[0005] (1) Based on measuring the DC side current and analyzing the DC side current spectrum to detect a single open circuit fault in the system, but this method needs to add a current sensor, and the detection time is longer;

[0006] (2) The open-circuit fault diagnosis method based on the average current Park vector transformation can correctly detect the switch position of the specific open-circuit fault of the system, but the detection time needs a fundamental wave cycle, and the detection time is longer;

[0007] (3) The open-circuit fault diagnosis method based on wavelet-neural network, the calculation of the algorithm is relatively complicated, and the calculation amount is relatively large

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