Research On Electromagnetic Interference Modeling Of PWM Motor Drive

With the continuous development of modern power electronics technology, electromagnetic compatibility issues become more and more prominent. In order to enable the device to work in complex electromagnetic environment, EMC research is quite necessary. Motor is the core element of various types of high-tech equipment, its electromagnetic compatibility has been the emphasis and difficulty of the study because of its complex structure and complex coupling channel.In response to this situation, this article makes intensive studies about electromagnetic interference of motor. The main contents are as follows:(1) Analysis of electromagnetic interference mechanism for PWM drive motor. Analyzing electromagnetic interference mechanism of IGBT which is the core components of PWM drive system. Establishing a simplified model of the IGBT, and analyzing the influences of interference sources on Conducted Interference. Electromagnetic interference mechanism of long-term cable of the PWM drive system was analyzed to establish a long-term cable model. The motor system itself and the kind of coupled channels are analyzed. Drawing a overall EMI conduction path graph of the PWM drive motor..(2) Study on the electromagnetic interference modeling method of PWM drive motor. Focusing on electromagnetic interference modeling of the motor body, and proposing two different modeling methods, one is the equivalent model, the other is external characteristic model. Advantages and disadvantages of these two methods are analyzed. Since the common mode and differential mode equivalent model equivalent model can not be represented in the same circuit, the impedance conversion network is proposed. Proposing a practical test method for the designed model. The method of the proposed model is validated by both simulation and experiments. Making error fluctuation figures to confirm the correctness and feasibility of the modeling method.(3) Study on the electromagnetic interference suppression of the PWM drive motor. Existing conducted interference test methods and conducted interference suppression methods are researched. The filter is redesigned combined with the special nature of PWM motor. Putting forward a feasible electromagnetic interference suppression method for the PWM drive motor.The main result of this study is electromagnetic interference modeling method of PWM drive motor. Based on different situations of the motor electromagnetic interference, various methods can be chosen. Using different methods can successfully build electromagnetic interference equivalent model or external characteristic model of PWM drive motor. The method presented in this paper has great significance for electromagnetic interference prediction and research of PWM drive motor.