Research Of Active Voltage Arc Suppression Device Control Method And Hardware For Distribution Networks

With the development of the distribution network,the line-to-ground capacitance current increases,resulting in too much grounding current,thus the arc caused by faults is hard to eliminate.The burning arc leads to the destruction of the power supply device,so the reliability of the power system.In order to remit the poor results which caused by the traditional grounding mode,this paper made a deep research in active arc suppression principle,device control method,the structure of hardware circuit and so on,mainly basing on the zero-sequence voltage flexible control theory.In terms of active arc suppression theory,the paper analyses the active voltage arc suppression device topology and working principle based on the fundamental domain and harmonic domain.The paper reveals the injection current and fault phase voltages quantitative relationship,and elaborates the basic principles of transient faults reliable arcs suppression that a zero-sequence current was injected to distribution network neutral point,and the value of fault phase voltage was controlled to be zero,the fault of active,reactive and harmonic components was compensated.In terms of device control method,the paper proposed active voltage arc suppression dual-loop method constituted by voltage outer loop and current inner loop,neutral point voltage and output current is controlled by a neutral device PI regulator.After studying the parameters of the PI regulator by root-locus method and Routh Criterion,using bode diagram analysis the influence of the controller parameters on the stability control system.A distribution network fault arc suppression system simulation model was built,from aspects of arc suppression effect,installed capacity and costs,comparative analysis of the fixed Petersen coil,active voltage arc suppression device,Petersen coil unit and the device parallel system.In terms of hardware circuit,active voltage arc suppression device based on the DSP controller was designed,the main power electronic circuits and control circuits for a detailed parametric analysis.The paper build a distribution network simulation arc suppression systems with open loop control method and dual-loop control method for experimental prototype experimental verification principle and control strategy of debugging hardware circuit.The simulation and experimental results show that the active arc suppression device can compensate for single-phase ground fault full current,which validated the superiority of the principle.The dual-loop control method proposed by the author does not require the measurement of the grounding parameters,which is simple and easy to realize.The hardware circuit is proved to be reasonable and practical,and reached the goal of arc suppression.