Fast electric arc light protection method

Abstract

The invention discloses a fast electric arc light protection method. A protection system consists of a singlechip, an arc light sensor, a current transformer and an exit relay. A switch cabinet arc light signal acquired by the arc light sensor is subjected to photoelectric conversion and amplification and sent to the singlechip; a switch cabinet current signal acquired by the current transformer is subjected to conversion and amplification and also sent to the singlechip; when working, the singlechip samples the input light signal and current signal according to set sampling frequency, calculates a relative mutation value of the light and a current light value after each sampling, estimates an effective current value of the next sampling moment according to the current increment and compares the relative mutation value, the current light value and the effective current value with respective set values; and if the relative mutation value, the current light value and the effective current value are all greater than the set values, the singlechip outputs a protection signal and cuts off the power supply of a switch cabinet through the exit relay. The method can eliminate interferenceof the current environment, namely false operation even under significantly bright conditions can be avoided; and impending arc light fault can be prejudged, so the response speed to the arc light fault is increased.

Description

technical field [0001] The invention relates to a method for monitoring and protecting an arc light fault of a medium and low voltage switch cabinet, and belongs to the technical field of protection. Background technique [0002] With the development of industry, the power consumption of each user is increasing, and the capacity of the medium and low voltage power supply and distribution system is also increasing. As a fast protection device for the medium and low voltage busbar, the arc protection device is also expanding its application field and market. [0003] When the arc protection device is working, the time from the detection of the arc fault signal to the action of the exit relay is directly related to the loss of users. As a protection device, in addition to having a fast response speed, it is also very important to select a stable and reliable criterion. Reasonable selection of the criterion is the premise of accurately judging the arc fault. However, for the ex...

AI Technical Summary

Problems solved by technology

The disadvantage of this protection device is that it is prone to misoperation in a bright environment, and when the current is close to the set value and increases sharply, it cannot predict the upcoming arc fault in time, and the protection action is lagging behind, so it cannot Get the ideal protection effect

Images