A method of tracing the source of voltage sag by using sequence active power incremental current direction

Abstract

The invention discloses a method of tracing a voltage sag source by using a sequence active increment current direction. A positive value or a negative value of a positive-sequence and a negative-sequence active increment current value before grid fault and during the fault is used for judging the position of the voltage sag source. A corresponding positive-sequence and negative-sequence active increment current algorithm is given, and the provided voltage sag source recognition method can correctly judge the voltage sag source positions caused by various kinds of grid fault, is applicable to a radial distribution network and positioning of other disturbance sources.

Description

technical field [0001] The invention relates to a method for automatic monitoring and positioning of pollution sources affecting the power quality of power supply in a power grid, in particular to an automatic monitoring and positioning method for positioning a voltage sag source of a power grid. Background technique [0002] Voltage sag refers to a phenomenon in which the rms value of the supply voltage suddenly drops to 90%~10% of the rated voltage amplitude in a short time, and its typical duration is 10ms~1min. Some highly automated equipment is easily affected by voltage sags, and several cycles of voltage sags will cause huge economic losses to industrial production. 80% of complaints. However, electric energy is a special product provided by the electric power department to the electric power users, and the quality is guaranteed by both the electricity supplier and the electricity user. On the responsibility for the decline of power quality, the two parties of power...

AI Technical Summary

Problems solved by technology

These positioning methods have relatively high positioning accuracy for voltage sags caused by symmetrical faults, but low accuracy for voltage sags caused by asymmetrical faults, and are only suitable for single-circuit radial power grids

The third category is perturbation method [11-14] , although the perturbation method has solved the problem of locating the source of the voltage sag well, it needs to set up a phase-locked loop for synchronous sampling

It should be noted that this method, like the first and second methods, is only applicable to radial distribution networks, and cannot be applied to complex grid networks like the disturbance method

Images