Remote intelligent residual current monitoring and protection system

Abstract

The invention discloses a remote intelligent residual current monitoring and protection system, which comprises a three-phase residual current protection device, single-phase residual current protection devices, a detection data / control signal transmitting device, a monitoring centre and a monitoring unit, wherein the three-phase residual current protection device is arranged on a three-phase main power line outlet; the single-phase residual current protection devices are arranged on three phases of power supply lines respectively; the monitoring unit is connected with the monitoring centre and also connected with a first stage of residual current protection device; the monitoring centre determines the upper limit value of split-phase / single-phase residual current of each phase of power supply circuit and monitors / analyzes the related detection data of a next stage of residual current protection device in real time; when the residual current on a certain phase of line exceeds the upper limit value, an alarm is sent; the amplitude of the residual current of each phase of line is monitored and adjusted to ensure the balance of the three-phase residual current; and the current of theneutral earth line of a power transformer is reduced and frequent tripping of the first stage of residual current protection device is prevented, so that the operating ratio and the reliability of the power grid are improved.

Description

technical field [0001] The invention belongs to the field of emergency protection circuit devices, in particular to a remote intelligent residual current monitoring and protection system. Background technique [0002] The International Electrotechnical Commission (IEC) refers to various residual current protection products as residual current operated protective devices (Residual curent operated protective devices, referred to as ReD), which means that when the residual current generated by the ground fault in the system exceeds the specified value, it can automatically break the circuit or An electrical device that emits an alarm signal. [0003] Residual current action protection device, also commonly known as electric shock protector or protector (protector) for short, is an important protective electrical device to effectively prevent low-voltage contact and leakage accidents. [0004] In 2001, the sixth expert seminar held by the Agricultural Electricity Society formed...

AI Technical Summary

Problems solved by technology

However, due to the unreliable operation of some residual current operated protectors in rural power grids, the operation rate of residual current operated total protectors in some provinces is low (see the statistical annual report of agricultural power accidents in recent years), which affects the safe operation and reliable power supply of rural low-voltage power grids sex

[0011] It can be seen from the above that in the past, in the technology of this industry, in the understanding of the coordination of the first, second and third level residual current protection devices of the power grid, it is simply considered that there is only the difference between the residual current operating value and the operating time. In this way, the problem of over-level tripping can be solved. The country has stipulated the standard for the interval between the first, second and third-level residual current protection devices in the power grid according to the size of the residual current and operating time, that is, the residual current of the upper-level residual current protection device. The action value must be greater than that of the next level, and the action time difference of each level is 0.2s, and each level of protection device works independently. It is believed that this can solve the problem of skipping tripping, which is correct in theory, but The final practice proves that it is not feasible, and the practice over the years has proved that this problem has not been effectively solved

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