The invention discloses a fault
range finding method of a power distribution network based on an equivalent positive and negative sequence impedance principle. According to the method, a PMU is used to obtain line state information in real time, and a fault line is determined by calculating and comparing the head-end line voltages in the same
branch point; normal line information is used to calculate the head-end
voltage and current of the fault line; and on the basis that electrical quantity of the two ends of the fault line is known, accurate fault locating is realized on the basis of the equivalent positive and negative sequence impedance principle. The difficulty that too many
branch lines are included in fault location in the power distribution network via the limited PMU, and accurate fault locating is realized; fault
range finding is realized by measurement in the two ends, it is not required to determine the fault type, the method is avoided from influence of transitional resistors or opposite-end feed-in current, and it is not required to consider the change of fault boundary condition or
system operation manner, and compared with the single-end measurement method, the
range finding precision is higher, fault range finding can be realized rapidly and accurately, the
operational reliability, safety and flexibility of the
system are improved greatly, and the applicationprospects are better.