Rapid warm raising measurement set for electric automobile motor drive system and measurement method

Abstract

The invention provides a device for measuring the rapid temperature rise of motor drive systems of electric automobiles and a measuring method thereof. The device comprises a high-voltage circuitbreaker used for breaking the connection of any quarter phase circuit between a motor and a motor controller; discharge resistance connected between any quarter phase circuit of the motor, which is provided with the high-voltage circuitbreaker to eliminate a winding residual voltage of the motor; a constant current DC source arranged between any quarter phase circuit of the motor, which is provided with the high-voltage circuitbreaker to provide constant current to the motor winding; a discharge switch used for connecting a discharge circuit; a measuring switch arranged in the circuit of the constant current DC source and used for connecting the loop of any quarter phase circuit of the constant current DC source and the motor. The device is based on the DC constant current source method and realizes automation measurement of the internal resistance of a milliohm-level motor winding. The resolution ratio can reach 0.1 milliohm, and the operation is safe and convenient.

Description

technical field [0001] The invention relates to the field of electric vehicle motor drive systems, in particular to a measuring device and a measurement method for rapid temperature rise measurement of the electric vehicle motor drive system. Background technique [0002] The working state of electric vehicle motor drive technology is very complicated. Due to harmonics, copper loss and iron loss, etc., the temperature of the motor will rise, which will affect the performance of the system, and in severe cases, the system will be damaged. In order to obtain the ideal temperature rise of the motor, the resistance method (voltammetry) test is mostly used at present. [0003] The calculation of winding temperature rise based on the resistance method must stop the motor under test as soon as possible after the temperature rise test reaches thermal stability, measure the instantaneous resistance value of the power failure, and directly calculate the winding temperature rise. Sinc...

AI Technical Summary

Problems solved by technology

At the same time, the motor winding is generally in the milliohm level, and its resistance value is only tens or hundreds of milliohms. It is very difficult to measure its resistance value with general testing instruments.

The existing high-precision resistance meter can realize the accurate measurement of milliohm level resistance, but it can only be measured manually, the test intensity is high, the safety is low, the test efficiency is low, and there is a certain delay in the measurement process. The resistance value takes a long time, and it is easy to affect the measurement accuracy and cause the test to fail

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