Modeling And Analysis Of Low-voltage Power Line Carrier Communication System

Low-voltage broadband power line carrier communication is widely applied to the ubiquitous power internet of things with its high-speed and convenient features in the information construction age.Such as intelligent meter reading system that provides communication guarantee for the interaction between the network and users.Therefore,low-voltage broadband power line communication has a good application prospect and attracts wide attention.However,complex distribution network,random access or disconnection of various electrical loads and noise interference limits power line communication efficiency.In order to analyze the factors affecting the power line channel characteristics and communication system,and to select appropriate communication standards for its power line carrier communication system under the known intelligent meter reading structure of residential areas,This thesis arranges research contents and makes conclusions as follows.Firstly,the transmission line theory is used to model the low-voltage power line channel,and Middleton A noise model is used to simulate the power line noise,which established a low-voltage broadband power line communication system model based on OFDM modulation technology collectively.The effects of whose channel topological parameters and noise parameters on channel and system were studied.Secondly,according to time-varying characteristics of common electrical loads in life,it can be divided into approximate constant impedance,time-invariant frequency-selective impedance and time-varying frequency-selective impedance.Then it was brought into communication system separately to study the impacts of different loads on power line channel and system.Finally,the established low-voltage broadband power line communication system model was substituted into the intelligent integrated transcription system of residential areas with known network structure,and the power line channel amplitude-frequency characteristics in the current channel structure and noise environment were analyzed.Then,taking three different broadband power line communication standards of HomePlug AV?HomePlug GP and G.hn as examples,to studied the impact of the three standards for the system model,and elected a appropriate standard for cell communication system.Simulation results in Matlab show that except for location of branches node,the variety of trunk length,branch length,branches number,electrical load's size and type all affect the position of notch frequency points or the amplitude of fading in the channel amplitude-frequency characteristic curve,thus affecting the system performance.In the case of constant total noisepower,the closer noise model is to Gaussian noise,the greater impact on the system.In this thesis,the impact of different communication standards on the system was simulated in the residential area meter reading system.It is found that the HomePlug GP standard has better performance.This thesis proves sensitivity of communication system to channel factors variety and provides a theoretical analysis basis for the application of low-voltage broadband power line communication.There are 59 papers,7 tables and 62 references in this paper.