System for integrating protective current sampling and power supply

Abstract

The invention provides a system for integrating protective current sampling and a power supply, and belongs to the field of protective relaying. The system comprises a current main loop control module, a multi-channel current dynamic acquiring module, an active output and input module, a standard communication module, a man-machine interaction module and a main CPU module; and the various modules are respectively connected with the main CPU module. By the integrated protecting system, a self-powered mode, namely a mode of taking power by a current transformer, can be selected, and added burden caused by mounting of a direct-current screen or a UPS is avoided; a common 2-wire-output primary current transformer is adopted, and protection operation of the system can be finished by 2 wires of each phase through protective current and the power supply. In places where power supplies are not required but a protection function is required, the system can be matched with a circuit breaker to completely replace a protecting mode in which a fuse and a load isolating switch are used, the load protection function of a power distribution network can be improved remarkably, the electric power cost is reduced, further, stability of an electric power system is improved, and the practicability is high.

Description

technical field [0001] The invention belongs to the field of relay protection of electric power systems, and in particular relates to a system integrating protection current sampling and power supply. Background technique [0002] At present, in order to adapt to the rapid and intelligent development of the power system and achieve the purpose of low cost and high reliability, it is necessary to use relay protection devices. In domestic power grids where no power supply is required and protection functions are required, the existing relay protection devices with protective current and power supply mainly adopt the scheme of increasing the winding difficulty of the primary current transformer so that the two outputs are independent The current or voltage; this leads to the corresponding relay protection device must also be divided into two ways to sample the current and power supply separately, in order to work normally. Therefore, there are still following deficiencies in t...

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Problems solved by technology

[0004] Second, the existing protection system is not stable enough, which adds hidden dangers to the power system;

[0005] Third, because multi-channel current or voltage output also means that the failure rate of the power system has doubled, and the external lead wires have also increased from 2 to 4 per phase, which increases the cost of the power system, and the multi-channel current of the device is introduced Also increases cost and failure rate

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