Self-adaptive leakage protection method for residual current operated protective device

Abstract

The invention discloses a self-adaptive leakage protection method for a residual current operated protective device. The self-adaptive leakage protection method is mainly applied to safety protection of the residual current operated protective device in a low-voltage power network distribution system, and accidents such as electric shock of a human body, electrical fires, electrical equipment damage and the like caused by electric leakage are prevented. On the basis of the characteristic that normal leakage current changes slowly along with time, a self-adaptive leakage protection model based on misoperation faults is established, and fault leakage and normal leakage can be recognized rapidly according to the change speed of the leakage current. When the leakage is judged to be normal leakage current change, a leakage operation gear value is changed automatically, self-adaptive leakage protection is realized, misoperation faults caused by normal leakage are overcome, that is, self-adaptation to the faults caused by factors such as change of the number of electric equipment, change of a power network structure, change of the atmospheric environment and the like can be realized, the leakage operation gear value is regulated automatically, so that frequent leakage protection operation is avoided, and the operation rate of a power network is increased.

Description

Technical field [0001] The invention relates to an adaptive leakage protection method for a residual current operated protector, in particular to a method capable of quickly identifying fault leakage and normal leakage according to the change rate of the leakage current, and automatically changing the leakage action gear value when the normal leakage current changes. Realize the adaptive leakage protection of the residual current operated protector, and overcome the malfunction caused by normal leakage. Background technique [0002] The working characteristic of the residual current operated protector (also called leakage protector) is that when a person gets an electric shock or the leakage current of electrical equipment exceeds a certain value, the protector should be able to act in a timely and reliable manner; otherwise, it should not act. At present, there are mainly two leakage protection failure modes. One is the failure to operate, that is, when someone gets an electric ...

AI Technical Summary

Problems solved by technology

However, on the one hand, the change of the normal leakage current may be caused by the increase or decrease of equipment, or the change of the branch circuit of the power grid; on the other hand, the normal leakage current also changes with the change of the environment, for example, the general As the temperature rises, the insulation resistance will decrease, and the normal leakage current will increase. At the same time, humidity will also affect the normal leakage current. The normal leakage current of the power grid will generally increase with the increase of humidity.

For this reason, the traditional leakage current protection technology is adopted. On the one hand, when the threshold value of the leakage action gear is set to be small, it often causes the leakage protection to operate frequently, resulting in a decrease in the operation rate of the power grid.

Forcing some users to take the residual current action protector out of operation without authorization, there is a major hidden danger of leakage protection

On the other hand, when the leakage protection action gear threshold is set to be large, the number of leakage protection actions can be reduced and the operation rate of the power grid can be improved, but the effectiveness of the leakage protection is reduced.

Images