How to withstand high temperature of permanent magnet motor?
High and low temperature environment of permanent magnet motor system device characteristics and indicators change greatly, the motor model and parameters are complex, the nonlinearity increases, the degree of coupling increases, the power device loss changes, not only the drive loss analysis and temperature rise control strategy is complex, and the four-quadrant operation control is more important, the conventional design of drive controllers and motor system control strategy can not meet the high temperature environment requirements.
Conventional design of drive controllers work in the ambient temperature is relatively stable conditions, and seldom consider the quality, volume and other indicators. However, under extreme working conditions, the ambient temperature varies within a wide temperature range of -70 to 180°C, and most of the power devices cannot be started in this low temperature, resulting in the failure of the driver function. In addition, the total mass of the motor system is limited, the heat dissipation performance of the drive controller is bound to be greatly reduced, which in turn affects the performance and reliability of the drive controller.
Ultra-high temperature conditions, the mature SPWM, SVPWM, vector control methods, such as switching loss is large, the application is limited. With the development of control theory and all-digital control technology, various advanced algorithms such as speed feedforward, artificial intelligence, fuzzy control, neuron network, sliding mode variable structure control and chaos control have been successfully applied in the servo control of modern permanent magnet motors.
For high-temperature environment permanent magnet motor drive control system, it must be based on physical field calculations, closely combined with the characteristics of the material and device characteristics of the changes in the establishment of the motor-converter integration model, field-circuit coupling analysis in order to fully take into account the impact of the environment on the characteristics of the motor system, and make full use of the modern control technology, as well as intelligent control technology, in order to improve the quality of the motor integrated control. In order to improve the comprehensive control quality of the motor, modern control technology and intelligent control technology are fully utilized. In addition, permanent magnet motors working in harsh environments are not easy to be replaced, and they are in long-time running conditions, and the external environmental parameters (including temperature, pressure, airflow speed and direction, etc.) change in a complicated way, which leads to the motor system working conditions. Therefore, it is necessary to study the design technology of high robustness drive controller for PM motors under the condition of parameter regression and external perturbation.
