Open-circuit fault diagnosis method of cascaded STATCOM system IGBT

Abstract

The invention discloses an open-circuit fault diagnosis method of a cascaded STATCOM system IGBT. A capacitance and voltage signal with a semi fundamental wave period serves as an original signal to be processed, features of fault signals can be maintained, and diagnosis instantaneity can also be guaranteed. By means of a multi-core least square support vector machine improved through a feature dimension reduction, diagnosis accuracy is improved, and diagnosis time is shortened. The method further reduces misdiagnosis caused by load changes, and inherits the small-sample learning advantage of a traditional SVM classification method.

Description

technical field [0001] The invention relates to a cascaded STATCOM system, in particular to an open circuit fault diagnosis method for an IGBT of the cascaded STATCOM system. Background technique [0002] The cascaded static synchronous compensator (STATCOM) device can compensate the capacitive or inductive reactive power of the grid system to enhance the stability of the grid system. A cascaded STATCOM system usually consists of a controller, a converter, a filtering device, and a cooling device. The failure of each part will affect the operation of the system, and in severe cases it will cause the system to shut down. Among them, the failure of the controller and cooling device has formed a mature solution through measures such as temperature monitoring and relay protection configuration. However, the insulated-gate bipolar transistors (IGBTs) that make up the H-bridge power module in the converter are also prone to failure due to the long-term working environment of high...

AI Technical Summary

Problems solved by technology

However, since the working environment of the STATCOM system is generally in high voltage and high electromagnetic interference, and from the perspective of industrial application (volume, power consumption, etc.), the design of various protections should not be too complicated, which increases the possibility of IGBT failure. probability

Restricted by the working environment, installation location, manufacturing process, etc., its reliability problem has not been effectively solved

The three-phase output voltage signal is used as the original signal, which is easily affected by the fluctuation of the power supply voltage, while the output current signal is easily affected by the fluctuation of the load, resulting in poor fault diagnosis effect and easy to cause misdiagnosis

In addition, the diagnosis time is longer

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