Research On Noise Analysis And Modeling Of Broadband Power Line In Low Voltage Distribution Network

Low-voltage power line communication technology has gained attention because of its simple wiring,wide coverage,low construction cost,etc.It is widely used in smart grids,smart homes,and energy internet.But it is also facing serious problems to be solved.One of the main factors is noise interference,which has become a bottleneck restricting its development.Based on this,it is necessary to study power line noise.This paper mainly starts from noise testing,characteristics analysis and model simulation.Based on this research,a noise hardware simulation platform is established to enable related researchers to study the effects of noise on power line communication systems under different scenarios in a laboratory environment.Firstly,the current research status of low-voltage power line noise is analyzed,and this paper adopts methods that is research the noise at the source.The working status of the electrical equipment is divided into continuous state and transient state.Typical electrical equipment generate noise are collected under various conditions in the low-voltage distribution network environment.In the continuous state,noise generated by electrical appliances is divided into random impulse noise and periodic impulse noise.In the transient state,noise generated by electric appliances is divided into class1 impulse noise and class2 impulse noise.Secondly,based on the existing modeling methods,a method that models single pulse of impulse noise is proposed for generating noise in continuous state.Markov chain is exploited to establish the frequency-domain extreme-point sequence statistical model.The obtained extreme point sequence fits the real part and the imaginary part of frequency domain waveform which can produce single impulse noise with envelopes in the time domain by Inverse Fast Fourier Transform.This method is exploited to simulate the noise generated by a typical electrical device,Simulation results show that the generated noise exhibits good envelope characteristics.The effectiveness of the method is verified.Finally,a design and implementation scheme of power line noise generator based on FPGA is proposed for the established noise model.The system generator rapid design tool was exploited to complete the design and implementation of Markov module,interpolation module and IFFT module,and build a source-side impulse noise generation module system.The IP core of the established system was loaded on the KC705 evaluation board to implement a noise generator.