A three-phase unbalance detection method and system for electric vehicle drive motor coils

Abstract

The invention discloses a three-phase unbalance detection method and system for electric vehicle drive motor coils. Considering that the characteristic parameters of the motor will change drastically before and after a parallel branch circuit of a certain phase of the motor coil is disconnected, the application can change the characteristic parameters of the motor to The sudden change of parameters is used as the diagnostic condition for the three-phase unbalanced fault of the motor coil. Specifically, the characteristic parameters of the motor used for the three-phase unbalanced fault diagnosis of the motor coil can be determined in advance, and then the three-phase unbalanced fault of the motor coil can be diagnosed by detecting the variation of the characteristic parameters of the motor. Phase unbalance fault. It can be seen that the three-phase unbalance detection method of the present application can detect the three-phase unbalance fault of the motor coil caused by the disconnection of a parallel branch of a certain phase; and the calculation process involved in this detection method is relatively simple, and the resource occupation time is relatively short, thus It is more suitable for motor drive control with higher real-time requirements.

Description

technical field [0001] The invention relates to the field of electric vehicle fault detection, in particular to a three-phase unbalance detection method and system for electric vehicle drive motor coils. Background technique [0002] As a new type of transportation, electric vehicles are used more and more widely. At present, as the core unit of the power output of electric vehicles, the drive motor is responsible for converting electrical energy into mechanical energy, and its performance directly affects the safety and reliability of electric vehicles. When the three-phase is unbalanced, the impact on the motor control output is directly manifested in the serious asymmetry and waveform distortion of the three-phase input voltage, current, and motor flux linkage of the electric drive system, and the characteristic parameters of the motor itself will also change dramatically. [0003] When the three phases of the motor coil are unbalanced, the following hazards will be caus...

AI Technical Summary

Problems solved by technology

However, the calculation of the unbalance degree of three-phase current or voltage involves the positive sequence, negative sequence, and zero sequence components of the three-phase current or voltage, and the amplitude and phase of the three-phase current or voltage vector must be calculated accordingly. The vector calculation process It is complex and takes a long time to occupy resources, so it is not suitable for motor drive control with high real-time requirements

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