High Frequency Modeling Of MV Electrical Equipment And Research On Characteristics Of Adaptive Coupling

As an economical and doable communication technology, MV distribution network carrier communication technology receives more and more widespread attention. However, at present, there are still many difficulties to set up the data channel by using the MV distribution network because of the multifarious connection and equipment parameters of the distribution network, as well as the high online noise of medium voltage power distribution, which usually causes the unpredictability and unmatched of the interface impedance. Therefore, it is the key to overcome the above problems and increase the stability of the signal transmission so as to realize the communications technology of MV distribution network.In view of the above problems, this article deeply analyzes and researches the characteristics of the main electrical equipments and coupling technique of carrier communication. It mainly involves the analysis of the impedance of the medium voltage distribution, impedance test of power lines, research of coupling ways and design of adaptive impedance matching system.When analyzing the impedance of the medium-voltage distribution network and the noise characteristics, the article summarizes the methods of impedance test and tests the impedance of a power line in one actual MV distribution network of Shanxi Linfen. Through the analysis of the two results of measurement, the characteristics of the impedance of the medium-voltage distribution network is summarized.The electrical parameters for the power lines in MV distribution network are theoretically calculated and the accuracy of the actual results are verified, which is the foundation for channel modeling and research on the carrier channel attenuation characteristics. Besides, the article also analyzes the simplified model for PLC transformer. Through data analysis of measurement of two transformers with different capacity, we can get the basic model of the transformer in high frequency.Finally, the impedance matching methods which are commonly used are introduced. Base on the impedance analysis of the MV distribution network and research on adaptive coupling ways, it puts forward a kind of automatic impedance matching system, and analyzes the impedance measurement circuit, the peak detection part and LC impedance matching part. In the end, experiments are done to verify the matching effect of the whole automatic impedance matching system.