Method for diagnosing fault of parallel IGBT inverters

Abstract

The invention discloses a method for diagnosing fault of parallel IGBT inverters. The method comprises the steps of firstly, acquiring three phase voltages which are output from the inverter, establishing a three-phase voltage matrix, and obtaining a state amount Uk; then, acquiring an IGBT conduction voltage drop Vi(k), comparing the Vi(k) with a threshold voltage drop Vce, forming an IGBT voltage drop Boolean matrix according to the comparison result, and determining whether a fault occurs according to the V(k); if yes, further comparing the Uk with the state amount Vk obtained from the V(k), if Uk is not equal with Vk, determining fault of a single IGBT or multiple non-parallel IGBTs, and otherwise, determining simultaneous fault of the parallel IGBTs; inputting the Uk into a set F; if state change of Uk values which are obtained through sampling by six times occurs, comparing F with a fault set FSi, and determining position of the fault. The method can realize quick diagnosis for the fault of the inverters.

Description

technical field [0001] The invention relates to a method for diagnosing inverter faults, in particular, the method can be used for diagnosing faults in parallel IGBT inverters, and the method detects and locates inverters through IGBT conduction voltage drop and three-phase voltage IGBT faults in the middle, so as to detect and report faults early, improve stability and safety. Background technique [0002] Inverters are widely used in industry, electric vehicles, high-speed trains and other fields due to their superior performance. , IGBT) aging rapidly, becoming a potential threat to train safety. The damage of IGBT will increase the workload of other power devices, which will lead to more serious secondary accidents, and finally cause train operation accidents. Although a protection circuit is added to the drive circuit of the inverter power device IGBT, load disturbance, grid disturbance, space electromagnetic interference, etc. will cause the protection system to fail...

AI Technical Summary

Problems solved by technology

At present, a lot of research is devoted to the research of inverter fault diagnosis methods, and most of them focus on ordinary inverters. These methods cannot be applied to the special working condition of parallel IGBTs.

Existing studies often use data analysis methods to extract eigenvalues ​​in the process of inverter fault diagnosis, which not only increases the hardware cost requirements of the system, but also delays the diagnosis time

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