The Analysis And Prediction Of EMI On AuxiHary Power Unit For Extended-Range Electric Vehicle

In recent years, new energy vehicles has been rapid development, on the one hand thanks to the ever-growing development of science and technology leading to dramatic development in automotive industry, especially in power electronics; on the other hand due to the increasingly severe environmental pollution and energy crisis prompting the countries and their major automobile manufacturers to put a lot of efforts in the research and development of new energy vehicles. The Extender-Range Electric Vehicles(E-REV) could be a perfect transition model from the traditional vehicles to pure vehicles. It can satisfy the need of travel commute in the pure electric pattern and, the extended range pattern solve the shortage of driving distance. So, the E-REV could be the most likely enter the family vehicle right now and be industrialization prospect of electric vehicle products.Compared to the traditional vehicles, the E-REV’s power system consist of more electronic devices and components leading to so many advantages such as energy-saving, safety, environmental protection and economy etc. At the same time, it brings very much serious electromagnetic interference problems. The Auxiliary Power Unit(APU) is the core component of the E-REV, and its engine and ISG motor is the strong interference sources, especially the engine ignition system, the electromagnetic compatibility(EMC) affects the safe operation of the system and even the normally function of the whole vehicle. therefore, analyzing the EMI of APU has very realistic significance.The method of this article is to split the APU for two parts of the engine and ISG motor based on the analysis of EMI for the APU, first analyze the respective mechanism of electromagnetic interference(EMI), and then set up the equivalent circuit model, at last verify the correctness of the model through the experiment. The paper first briefly introduces parameter matching, control strategy and related knowledge of the E-REV, and then analyses the vehicle’s EMI environment, propagation path and solutions. On this basis, first engine ignition system mechanism of EMI for APU is analyzed from the primary and secondary circuit, then followed by modeling for the seven sub-modular: primary circuit module and high damping module, ignition control and artificial mains network module, ignition coils and spark plug equivalent circuit module. In the next, analyzes the mechanism of ISG motor EMI, and ISG motor is modeled based on the impedance characteristics of single-phase broadband equivalent circuit model. In this paper, the curve of the model are compared with the measured data, and has a very good consistency between each other to prove the effectiveness of the method described in this article. The last part is the whole model validation of the extender, respectively from the engine and ISG motor as a whole to prove the validity. The conclusion is that the model in this paper has a good consistency with the actual measurement data in verifying the reliability of the presented modeling method, proving a good analytical method and basis for the EMC of APU or even the whole vehicle. In the end, the modeling of this paper has the very good engineering analysis and practical application value.