With the aggravation of the energy crisis and people’s yearning for clean energy, the state and various industry institutions have invested a lot of resources in the research of pure electric vehicles, hybrid vehicles, fuel cell vehicles and other new energy vehicles, and the three key technologies of new energy vehicles are power supply, motor and electric control. For the power supply, especially for energy storage systems (such as power batteries), there are relatively mature test programs and equipment (such as advanced battery simulators in the world, which can be used to charge and discharge power batteries).
The vehicle power supply system can adopt fuel cell system, gasoline and diesel engine-generator system or alternative fuel engine-generator system, and the energy storage system can adopt energy storage systems such as chemical batteries, super capacitors or flywheel storage systems. The main drive motor system is mainly composed of a motor and a controller, and its task is to efficiently convert the electric energy of the battery into the kinetic energy of the wheel under the control of the driver, or feed the kinetic energy of the wheel into the battery.
The motor drive system is the heart of electric vehicles, and its reliability directly affects whether electric vehicles can be widely used. Therefore, it is necessary to test the reliability of the motor to ensure that the motor drive system has enough average life.
The reliability test of the new energy vehicle drive motor is mainly a validation test to verify whether the motor meets the reliability requirements, which belongs to the validation test of the average life (average trouble-free working time) under a certain level and a certain reliability, that is, to test whether the average trouble-free working time meets the design requirements, and is the purpose of the motor reliability test. According to the different test scheme, the life test is divided into complete life test and truncated life test.
The complete life test is to make all the test motors work until the failure occurs, which can better reflect the actual distribution of motor life, and is more suitable for field tests to verify the type of life distribution.
The truncated life test is divided into two types: timing truncated life test and fixed number truncated life test. The timed truncated life test is to reach the specified time cut-off test, while the fixed number truncated life test is to reach the specified number of motor failures when the cut-off test occurs. Minor motor failures can be eliminated in a short time and the test can be continued. Therefore, it is suitable to adopt the truncated test without substitution.
The reliability of the motor of new energy vehicles is generally high, the life of the motor will be particularly long, and the use of full life test is unrealistic, so the motor is generally used for truncated life test. According to whether the actual stress affecting the life is changed, the life test is divided into conventional life test and accelerated life test. The conventional life test is carried out under the premise of simulating the actual working environment stress of the motor. The accelerated life test is to increase the stress life test which affects the motor failure without changing the motor failure mechanism. Conventional life test is a real simulation of the actual operation of the motor, with high accuracy, but the test time is relatively long, consumes manpower and material resources, and is an obstacle to technology research and development and motor mass production. The accelerated life test time is short, the cost is small, and the life prediction is a certain estimate, so the acceleration test is generally reasonable (without changing the failure mechanism of the motor) to quickly measure the life of the motor.
Post time: Sep-30-2024
