Distribution line three-section current protection configuration method based on virtual circuit breaker

Abstract

The invention discloses a distribution line three-section type current protection configuration method based on a virtual circuit breaker. The method comprises the steps of A judging whether a circuit breaker with mismatched protection exists or not; B judging whether a branch without a circuit breaker exists in the protection range of the circuit breaker with mismatched protection or not; C setting a virtual circuit breaker; D setting the circuit breaker with mismatched protection to be in a mismatched protection state; E setting the protection fixed value of each circuit breaker on a to-be-detected line again; F continuing to judge whether a circuit breaker with mismatched protection exists or not; if yes, setting the circuit breaker with mismatched protection to be in a mismatched protection state, and then returning to the step E; and if not, entering the step G; G judging whether a fault indicator is installed at the head end of the branch; and H linking the fault indicator installed at the head end of the branch with the upper-level circuit breaker with mismatched protection. According to the invention, the mismatch phenomenon caused by the fact that a local branch is not provided with a circuit breaker can be avoided.

Description

technical field [0001] The invention relates to the technical field of electric power system automation, in particular to a three-stage current protection configuration method for distribution lines based on a virtual circuit breaker. Background technique [0002] At present, when the power system distribution lines are equipped with three-stage current protection, most of them only set the fixed value according to the actual situation on site, and the premise that the fixed value can meet the selectivity, sensitivity and quick action of relay protection is that each The position of the circuit breaker on the line is set reasonably. In reality, due to the long-term and unbalanced power grid construction and the limitation of investment quota, the line construction and transformation in many areas is carried out gradually every year, and it is very likely that the position of the circuit breaker is unreasonable at a certain stage. A common situation is that the branch line l...

AI Technical Summary

Problems solved by technology

However, in reality, due to the long-term and unbalanced power grid construction and the limitation of investment quota, the line construction and transformation in many areas is carried out gradually every year, and it is very likely that the position of the circuit breaker will be unreasonable at a certain stage. A common situation is that the branch line lacks a circuit breaker, or only a fault indicator is installed, such as figure 1 As shown, if the setting calculation is still carried out according to the actual situation on site at this time, that is, according to the step-by-step coordination of the circuit breaker and the protection installation position, the current section I (quick-break protection) and current section II (time-limited current) of the upper level circuit breaker of the branch line may appear. Quick-break protection) setting value cannot meet the requirements of selectivity and sensitivity at the same time, thus affecting the setting of each protection at the lower level

In this regard, the conventional method is to sacrifice the selectivity of protection, and only configure the fixed value from the perspective of sensitivity. Although all faults can be guaranteed to be removed, there may be a situation of skipping trips, which will cause the expansion of the power outage range and affect the reliability of power supply.

Images