Research On Electromagnetic Compatibility Of Low-Voltage Power Line Carrier Communication And Household Appliances

In the electric power industry, low-voltage power line carrier communication has attracted wide attention and become a research hotspot of the world scientific research units and companies due to its unique advantages, the stability conditions of using and huge market. At the same time, with its advantages, the low-voltage power line carrier communication technology is widely used in the electric energy data acquisition system and the advanced measurement system. It has become the core technology of the construction process of smart grid in china. Because the low-voltage power line is designed to transmit power, so it does not consider the demand of communication. During the application process of low-voltage power line carrier communication, the channel characteristics are very adverse. Low-voltage distribution network access to a lot of household appliances, which makes the channel transmission characteristics and electromagnetic environment are very complicated. Therefore, the research on electromagnetic compatibility of the low-voltage power line carrier communication and household appliances is necessary.This paper researches the electromagnetic compatibility of low-voltage power line carrier communication and household appliances, specifically as follows:(1) The development process and the present research status of low-voltage power line carrier communication technology and communication system are described. Then, we analyze the present situation of research on electromagnetic compatibility of low-voltage power line carrier communication and household appliances. The currently existing problems and the development trend of low-voltage power line carrier communication technology are studied.(2) By using mechanism modeling method, the new hierarchical interpretative structural model of low-voltage power line carrier communication system is proposed. On this basis, we analyze the multipath transmission path of the carrier signal and establish a multi-port and time-varying topology model. Then, a carrier transmission model of load node is built, and the transmission of the carrier signal in household appliances is analyzed. Finally, we install the model of load impedance.(3) Through theoretical analysis and circuit simulation analysis, we research the mutual effect of low-voltage power line carrier communication and heating household appliances, including the effect of low-voltage power line carrier communication on household appliances and the effect of household appliances on low-voltage power line carrier communication. Then, circuit units are confirmed which are accessibly affected by carrier signal, and we establish the equivalent circuit of the effect of carrier communication on household appliances.(4) In view of the domestic and foreign EMC standards cannot solve the problem of electromagnetic compatibility testing for the mutual effect of the low-voltage power line carrier and household appliances, we design the electromagnetic compatibility testing system. Based on this system, the testing method is proposed, and the modifications the relevant EMC standards are suggested.(5) According to the testing system and testing method, we test and analyze the interact effect of the low-voltage power line carrier communication and household appliances. Then, we research and analyze the characteristics of the carrier channel of impedance distribution. Because of the problem of the interaction between the low-voltage power line carrier communication and household appliances, so we put forward a method to solve that. Finally, the efficiency of the method is verified.