Distribution Network Arc Suppression Coil Distributed Compensation and Its Influence on Fault Line Selection

With the increasing scale of distribution network and the large number of cable applications, the capacitive current of the system increases continuously. The conventional compensation method of arc suppression coil is limited by the capacity of the device or the space of the substation, so many substations cannot meet the compensation requirements. Distribution network arc suppression coil parallel resistance grounding has the advantages of both arc suppression coil grounding mode and resistance grounding mode. However, the arc suppression coil parallel resistance grounding is not pieced together simply by the two grounding modes, and there are some technology problems needed to study deeply. These are studied for arc suppression coil parallel resistance grounding mode in the paper, including resistance value, put into time and run time of the resistance and so on. Based on protection tripping and isolating fault quickly after single phase grounding fault, and considering to sensitivity of protection and personal safety (touch voltage and step voltage), these control strategies are put forward, which include resistance value of parallel resistance, using adjustable resistance technology proposal and its adjustable range, put into time and run time of the resistance, and the fault line selection characteristic quantity. It is suggested that the distributed compensation device should be installed on the bus or the first end of the line. If it is installed at the end of the line, in order not to affect the fault line selection, its capacity should be selected according to the undercompensated capacitance current of the line.