Design Of The Medium-voltage Power Line Channel Noise Generator Based On Virtual Instrument

Medium voltage power line communication technology is one of the important communication means in smart grid applications. The reliability of medium power line communication is limited by channel noise, signal attenuation and input impedance. And the channel noise which is time-varying and random is the biggest effect. This uncertain noise makes researchers encounter difficulties in the study of modulation/demodulation techniques and error correction coding. In order to provide convenience to the debugging of modulation and coding hardware circuit in medium voltage power line communication, it is necessary to analysis the medium voltage power line noise characteristics and study the modeling of the power line noises. And then design a medium voltage power line channel noise generator.The causes, types and characteristics of medium voltage power line channel noises are described in this paper. A measurement circuit of the power line channel noise is built. And then the medium voltage power line channel noise is measured and analyzed. Based on the measured noise, the parameters of channel noise are extracted and the main medium voltage power line channel noise simulation models are built. A medium voltage power line channel noise generator is designed based on virtual instrument technology.The AR model of power line background noise is established. The order and parameters of the AR model are estimated by BIC criterion and burg algorithm. The hidden Markov chain model of pulse width and interval time is established based on the measured noise data. At last the background noise and random impulse noise which match the power line channel noise characteristics are simulated.The medium-voltage power line channel noise generator is designed by using virtual instrument technology based on the noise models. The background noise and random impulse noise can be produced by the noise generator. The front panel and block diagram of noise generator are designed in the medium-voltage power line channel noise generator. Noise parameters can be adjusted and noise waveform can be observed in the front panel. At last, the noise data is produced by virtual instrument acquisition card and output by amplifier circuit.