Open-circuit fault diagnosis method for three-phase induction motor driving system

Abstract

The open-circuit fault diagnosis method for the three-phase induction motor driving system comprises the following steps: constructing a mathematical model of the three-phase induction driving system, and establishing a current dynamic equation of an asynchronous motor driving system under a static coordinate system; discretization is carried out to obtain a prediction value, and a finite set model prediction control scheme of the induction motor driving system is designed; constructing a cost function of each phase of current on the basis of a model predictive control framework; the sliding integral is introduced into a phase current cost function; through comparing the size relation between the sliding integral value of the phase current cost function and the threshold value and combining the symbol of the current error variable, a corresponding table of the relation between different open-circuit faults and the sliding integral value and the current error of the phase current cost function is obtained, and the specific fault switch position is judged by looking up the table. According to the method, an additional sensor is not needed, the method is robust and reliable, due to the fact that the sliding integral filter based on the residual error is adopted, the appropriate threshold value is very easy to determine, and the good threshold value is achieved to reduce the false alarm rate and improve the omission ratio.

Description

technical field [0001] The present invention relates to an open-circuit fault diagnosis technology of a converter drive system, and more specifically, relates to a sliding-integral filter-based open-circuit fault diagnosis method for a three-phase induction motor drive system, which is especially suitable for electric vehicles with high reliability requirements , electric locomotive and other applications. Background technique [0002] It is reported that more than 30% of electrical faults in AC drive systems are power circuit faults. Most of these are semiconductor device failures, such as switch opens and shorts. Typically, AC drive systems are very sensitive to failures in semiconductor devices. Once a semiconductor device fails, it must be dealt with in time. Otherwise, huge economic losses and safety accidents will be caused, especially in some applications with high safety requirements. Therefore, it is very important to accurately detect and isolate faults, which ...

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Problems solved by technology

However, this method is highly dependent on model parameters, which affects the robustness of the diagnostic system.

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