Intelligent electric leakage remote monitoring protector of low-voltage power grid

Abstract

An intelligent electric leakage remote monitoring protector of a low-voltage power grid comprises a zero sequence current mutual inductor, a main switch and an electric leakage protection intelligent processing module. The electric leakage protection intelligent processing module comprises an I / U converter, an analog / digital (A / D) converter, a data memory and a central processing unit (CPU) which are electrically connected in sequence. The CPU, a trip outlet interface, the main switch, a state quantity acquisition interface and the CPU are electrically connected in sequence. A communication interface is respectively and electrically connected with the CPU and a remote communication module, and a remote master station is communicated with the remote communication module. The CPU is respectively and electrically connected with a keyboard, a display screen, an audible and visual alarm and a clock module. The intelligent electric leakage remote monitoring protector of the low-voltage power grid has the advantages of displaying visually, storing electric leakage current value automatically, and being capable of prompting alarm information automatically. Precision of electric leakage current is high, measuring range is large, electric leakage protection delay can be set randomly, electric leakage protection action can be set flexibly, and the main switch can cut off power supply rapidly to achieve purposes of electric shock protection and electric leakage protection.

Description

technical field [0001] The invention belongs to the technical field of power grid leakage monitoring equipment, and in particular relates to an intelligent low-voltage power grid leakage remote monitoring protection device. Background technique [0002] Leakage protector is an important protective device for low-voltage power grid. It has the functions of preventing personal electric shock, preventing electrical fire and electrical equipment damage caused by leakage, and preventing power loss caused by leakage current. Currently commonly used low-voltage leakage protectors are classified according to the different characteristics of the electrical signals that cause their actions, and can be divided into voltage action types, current action types, and AC pulse types. Current-operated leakage protector is one of the most widely used leakage protection devices in urban and rural low-voltage power grids in my country. Its main components are: zero-sequence current transformer T...

AI Technical Summary

Problems solved by technology

[0003] The amplifying components of the above leakage protector mainly adopt two kinds of amplifiers, electromagnetic and electronic, which have the following defects: 1. It is impossible to display and store the leakage current value when the low-voltage power grid is in normal operation and when a shock or leakage occurs; 2. The leakage current range The range is small, and it is difficult to improve the sensitivity in high-current application environments (such as grid current above 100A), or it is easy to cause the leakage protector to burn out; 3. The setting of protection action value and action delay value is not intuitive and accurate; 4. It is impossible to perform hierarchical and segmental settings according to the actual needs of the low-voltage power grid, to perform tripping or alarm tasks, and to temporarily exit the tripping action protection of the leakage protector remotely; 5. All detection values, state quantities, setting values ​​and other data and Protection parameters cannot be remotely monitored and set; 6. It is impossible to automatically memorize and store event data such as the action time, value and number of leakage protectors, which is inconvenient to analyze the action of power grid leakage protection; 7. Leakage current during low-voltage power grid operation It cannot be directly collected through the leakage protector, and it is impossible to analyze the change of the leakage current of the power grid and the change trend of the power grid insulation

When the branch leakage protector and the household leakage protector themselves fail, the occurrence of instantaneous leakage faults, periodic leakage faults and permanent leakage faults of the low-voltage power grid often cause the total leakage protector to operate, resulting in the entire distribution transformer The power grid in the district is out of power, and it is difficult to quickly analyze, judge and deal with the fault point, which greatly reduces the reliability of power supply

In some extreme cases, due to the low insulation of the power grid itself, the large leakage current, or the difficulty of finding the grounding point, etc., the operation and maintenance personnel are often forced to withdraw or remove the leakage protection for a long time in order to ensure power supply. in an unsafe operating state

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