A method for locating voltage sag source based on sequence disturbance active current direction

Abstract

The invention discloses a voltage sag source locating method based on a sequence disturbing active current direction and belongs to automatic monitoring methods for power grid voltage sag source locating. The voltage sag source locating method includes: during power grid fault, a voltage sag source is located accurately by the disturbing active current direction under the action of disturbing voltage according to a linear circuit superposition principle; when disturbing active current is positive, a disturbing source is at the upstream position of a monitoring point; when the disturbing active current is negative, the disturbing source is at the downstream position of the monitoring point; a corresponding disturbing active current algorithm is defined and provided. The voltage sag source locating method based on the sequence disturbing active current direction has the advantages that the method is capable of locating voltage sag caused by various power grid faults determinately and applicable to power grids of radiation-type, ring-type, single-loop, double-loop, single-power-source and multi-power-source grid structures as well as voltage sag source locating caused by disturbance resulting from capacitor switching, transformer switching and large motor starting; voltage and current of the monitoring point need to be sampled synchronously according to the voltage sag source locating method.

Description

technical field [0001] The invention relates to an automatic monitoring method for locating a power grid voltage sag source, in particular to a method for locating a voltage sag source based on the direction of disturbance active current. Background technique [0002] Voltage sag refers to a phenomenon in which the root mean square value of the supply voltage suddenly drops to 90% to 10% of the rated voltage amplitude in a short period of time, and its typical duration is 10ms to 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. According to foreign surveys, voltage sags have become the main cause of complaints in power quality problems, and even account for 80% of the proportion of complaints. However, electric energy is a special product that is provided by the power sector to power users and whose quality is jointly guaranteed by both the power supplier an...

AI Technical Summary

Problems solved by technology

These positioning methods have a relatively high accuracy rate 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 grids.

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