Open-circuit fault diagnosis method for high-speed rail traction system single-phase three-level rectifier

Abstract

The invention provides a switch tube open-circuit fault diagnosis and positioning method of a high-speed rail traction system single-phase three-level rectifier, and belongs to the field of fault diagnosis. The method comprises the following steps of establishing a hybrid logic dynamic model, establishing a novel self-adaptive sliding mode observer, providing a primary diagnosis self-adaptive threshold, performing primary fault diagnosis, providing a secondary diagnosis self-adaptive threshold, performing secondary fault diagnosis and positioning, providing a third diagnosis self-adaptive threshold, and performing third fault diagnosis and positioning. According to a self-adaptive sliding mode observer provided by the invention, a system does not need to provide a very accurate dynamic model, only a sliding mode surface needs to be reasonably designed by utilizing a tracking error of a track, and the approaching rate can be adaptively switched, so that the approaching speed is accelerated, buffeting of sliding mode motion is reduced, and the diagnosis accuracy is improved; according to the method, fault diagnosis and positioning are carried out on a switch tube by comparing the relation between the residual characteristic quantity and the self-adaptive threshold value.

Description

technical field [0001] The invention relates to the field of fault diagnosis, in particular to a method for diagnosing the open circuit fault of a switch tube of a single-phase three-level rectifier in a high-speed rail traction system. Background technique [0002] The traction drive system of high-speed railway is an important part of high-speed train, and its safety and reliability directly affect the operation of high-speed train. The traction rectifier is one of the core components of the high-speed rail traction drive system, which is prone to failure, causing serious casualties and property losses. [0003] The traction rectifier is a single-phase three-level rectifier, and the diagnosis method for the open circuit fault of the switch tube of the single-phase three-level rectifier mainly includes the following two diagnosis methods according to the characteristics of the diagnosis object: [0004] 1. Diagnosis method based on current characteristic quantity. This ty...

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Problems solved by technology

Specifically, through the sliding mode observer and the use of sliding mode control, the problem of difficulty in establishing an accurate system model can be solved only by rationally designing the sliding mode surface, but this method will produce jitter characteristics during the control process, and then design Adaptive approach rate, through the adaptive switching approach rate to reduce the jitter characteristics in the control process, and further improve the accuracy of system fault diagnosis; at the same time, when performing fault diagnosis based on the characteristic quantity of current, by designing the adaptive threshold To suppress the inherent or external uncertain disturbances of the system, increase the accuracy of the diagnostic method, and improve the diagnostic accuracy; finally, in the fault location, according to the fault system model, an adaptive sliding mode observer under the specific open circuit fault state of the switching tube is established to Reproduce the system grid-side current output when a specific switch tube open circuit fault occurs and compare it with the actual sampled grid-side current to locate the faulty switch tube

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