A New Active Arc-suppression Algorithm Of Single Phase Earth Fault

Active arc suppression method is that when single phase earth fault occurs in distribution network, inject current into distribution by active inverter and compensate fault current completely to zero, thereby prompting arc extinguish as quickly as possible and avoiding arc reigniting to the greatest extent. The existing active arc suppression algorithm all measure capacitance to earth before earth fault occurs, measure system neutral impedance after earth fault occurs, calculate injection current. After small current earth fault occurs the distribution permits fault operation for 2 hours, if the line of distribution change, the existing active arc suppression algorithm can’t ensure fault current to zero. So putting forward an active arc suppression algorithm based on data after earth fault to calculate injecting current is necessary to practical application of active arc suppression method.This paper constructed and analyzed active arc suppression zero sequence model of distribution, put forward a new algorithm of active current arc suppression. It uses existing distribution automation equipment, measures zero sequence current and zero sequence voltage after earth fault in time to calculate injecting current. This paper analyzed fault current formula and change rules in passive and active voltage arc suppression method, put forward a new active voltage arc suppression algorithm which calculate injecting current based on two injecting current and bus zero sequence voltage.This paper analyzed the arc suppression performance of these two new algorithm under different transition resistance. Integrated the advantage of these two new algorithm, put forward an integrated algorithm of active arc suppression and improved the method which distinguish arc existing or extinguish. The MATLAB simulation results verified the accuracy and feasibility of these new algorithm and distinguish method.The new active current arc suppression algorithm can adapt dynamic change of most line construction in time. It used existing distribution automation equipment, so it is convenient to implement and has obvious economic benefits. The new active voltage arc suppression algorithm just used two injection current and bus zero sequence voltage to calculate injection current. It can completely adapt line construction dynamic change. It is easy to measure and control. The integrated algorithm has good arc suppression performance when the transition resistance is large and small. It can reflect distribution network structure changes, and it is easy to implement, which is good for actual application of active arc-suppression method.