Research On Noise Characteristics Of Photovoltaic Module And Module Serial Carrier Communication Channel

With the rapid development of the photovoltaic industry,fault monitoring of photovoltaic power plants has become an important research topic.In order to realize the monitoring of medium and large photovoltaic power plants,the carrier module communication technology using photovoltaic modules and modules serial as a medium can be used to transmit the operating data of photovoltaic modules.Photovoltaic array channel noise,especially the periodic pulse-shaped noise among it,seriously interferes with carrier communication,so it is necessary to grasp the characteristics of photovoltaic array channel noise.This paper studies the impedance attenuation characteristics,channel noise characteristics,and electromagnetic interference characteristics of photovoltaic array channels,focusing on the channel noise characteristics.An experimental platform was built to measure the noise of photovoltaic serial channel,analyze the electromagnetic interference generated by photovoltaic serial itself and photovoltaic inverter,and construct the equivalent circuit model of electromagnetic interference.In this paper,the noise modeling technology of photovoltaic serial channel is studied deeply.Based on the time-domain waveform of the noise of the photovoltaic serial channel measured in the photovoltaic power station,several modeling methods of the noise of the photovoltaic serial channel such as the wavelet peak-type markov chain,the BP neural network model optimized by decomposition algorithm and the BP neural network optimized by intelligent optimization algorithm are proposed.According to the simulation results,the output noise of the wavelet peak-type markov chain noise model has a high fitting degree with the original measurement noise.When the peak value of the original noise reaches 20V,the average absolute error of the model is only 0.4926V.The modeling effect of the composite artificial neural network model is smaller than that of the wave peak-type markov chain noise model,and the prediction error of the photovoltaic cascade channel noise is reduced by an order of magnitude.In order to master the characteristics of photovoltaic array channel noise,this paper mainly tests the noise of photovoltaic serial channel,studies the modeling algorithm of photovoltaic serial channel noise,conducts simulation analysis on each noise model proposed,providing an important theoretical basis for studying the carrier communication of photovoltaic power station.