Electric shock and electric leakage protection device for low voltage power grid

Abstract

The invention discloses an electric shock and electric leakage protection device for a low voltage power grid. The electric shock and electric leakage protection device comprises a power circuit, an electric shock and electric leakage signal detection circuit, a signal processing circuit, an intelligent judgment circuit, a bus-grounding monitoring device, an electric shock executive circuit, a power failure executive circuit and a power supply main loop power failure switch; uniform signal acquisition of electric leakage and electric shock of the system is performed, and different executive circuits are adopted after authentication and separation; in an electric shock accident, the electric shock and electric leakage protection device can protect the low voltage power grid without power failure; meanwhile, the bus-grounding monitoring device is adopted to keep the power grid normally running without changing the structure of the conventional power grid, and restrain an electric shock or electric leakage current to a personal safety range by changing the resistance of an electric shock loop; moreover, the state of the system can be checked, so the safety protection can be carried out by controlling switch on and off of the main circuit switch via the executive circuit according to a secondary electric shock detection signal of the bus-grounding device.

Description

technical field [0001] The invention relates to a contact and leakage protection device for a low-voltage power grid. Background technique [0002] Leakage protection technology is widely used in industrial and mining enterprises, urban and rural power grids, and low-voltage power supply systems in various special fields. It plays an important role in protecting the safety of people, equipment, and lines. recognized. Practice has proved that the use of electric shock and leakage protection appliances is the most effective method among various electrical safety protection measures. According to the statistical results, in countries and regions where contact and leakage protectors have been basically popularized, the accidents of contact and leakage have dropped significantly, and the success rate of protection is significantly higher than that of protective grounding method, protective zero connection method, double insulation method, position insulation method, etc. Althou...

AI Technical Summary

Problems solved by technology

[0005] The basic principle of voltage action protection is to connect induction coils in series to the general grounding of equipment or lines. The disadvantages of this method are: 1. The application range is limited, and it can only be used for a single equipment or a system where the neutral point is not directly grounded.

2. An auxiliary neutral point or a relatively far-distance grounding point is required to connect the control circuit, which increases the difficulty of installation

3. It can only be used for indirect contact protection but not for direct contact protection, so its promotion and application are greatly restricted

For example, when someone gets an electric shock, if there is no end protection or there is a fault in the end protection, or if there is an electric shock in the line above the end protection, when a more advanced protection action is required, due to the large action setting of the shunt and the total protection , the movement is slow, even if the movement is done, it often causes damage, and such a phenomenon is easy to happen in reality

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