Model based IGBT open-circuit fault diagnosis method for traction inverter of CRH3 electric multiple unit

Abstract

The invention discloses a model based IGBT open-circuit fault diagnosis method for a traction inverter of a CRH3 electric multiple unit. The method comprises the steps of (1) establishing a bond-graph model of the traction inverter; (2) deducing a system behavior constraint equation of the model; (3) based on the system behavior constraint equation, identifying the state of each current switch by utilizing a least square method; (4) performing difference operation on each IGBT pulse signal (represented by 0 or 1) given by a control system and the state (represented by 0 or 1) of each current switch to obtain six fault identification vectors; and (5) if an element in the fault identification vectors is greater than 0, indicating that an open-circuit fault occurs to a corresponding IGBT. According to the model based IGBT open-circuit fault diagnosis method for the traction inverter of the CRH3 electric multiple unit, when faults occur to any one or two IGBTs, the faults can be detected and positioned quickly and accurately; and the problem that a model based method cannot complete multi-fault identification in the field is solved.

Description

technical field [0001] The invention relates to the field of traction transmission, in particular to an online diagnosis of an IGBT open circuit fault of a CRH3 type traction inverter. Background technique [0002] my country's high-speed railway EMUs generally adopt the AC-DC-AC transmission mode, and in the AC transmission system, a considerable part of the faults are caused by power device failures. The short-circuit fault of power devices is generally converted into an open-circuit fault by hardware. After the IGBT open-circuit fault occurs, the motor can still run in an abnormal state for a period of time, but if it is not dealt with in time, it may lead to serious consequences. Therefore, it is of great significance to study the online diagnosis of traction inverter IGBT open circuit fault. [0003] At present, some model-based methods have been proposed for traction inverter IGBT open-circuit faults. These methods deduce the analytical redundancy relationship of th...

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Problems solved by technology

However, when two or more faults occur, the relationship between the consistency vector and the fault is usually not one-to-one correspondence, so these methods cannot detect and locate two or more faults well, and then As a result, effective measures cannot be taken in time to avoid the expansion of losses and the occurrence of accidents

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