Research On Impedance And Attenuation Charaeteristics Of The Low-voltage Power Line Carrier Communication Channel

Low-voltage power line carrier communication (LV-PLC) has become an important mean of local communication in the undergoing China’s smart grids. But the poor environment on the low voltage power line has a bad effect on the performances of LV-PLC, so understanding of the power line channel characteristics becomes vital.Characteristics of impedance and attenuation are two main factors-influencing the reliability of LV-PLC. On the basis of current situation that the narrow-band LV-PLC is widely being used in the remote power-meter reading system, this paper has an exploration of the two characteristics above through field measurement, modelling, experimental verification and software&hardware simulation. This paper provides field measurement methods of the impedance and attenuation characteristics, and implements a field measurement on the selection of some typical distribution networks.Then both characteristics measured in the frequency range of SO k-500kHz is summarized and analysed. After summarizing different modeling solutions, the two-port network matrix theory is adopted as the modeling theory. What’s more, this paper also establishes the low-voltage carrier transmission line model using the transmission line theory and the low-voltage appliances impedance characteristic model using Vector Fitting, both which are used as parameters serving the two-port network matrix model. In order to cofirm validity of the model, a small tree-like topology network is set up to simulate the low-voltage distribution network in the laboratory. The model can be verificated by comparing the attenuation and input impedance calculated through model with the both measured at different network nodes. At last, taking the two-port network matrix modeling theory as the basic algorithm, the LV-PLC impedance and attenuation simulation software is written by using the Matlab-GUI. RLC array (Resistance, Inductance, Capacitance array) is designed to achieve the hardware simulation of impedance characteristic. Thus, a complete solution is formed with field measured data supporting to simulate the impedance and attenuation characteristics of the low-voltage power line carrier communication.