Digital current synthesizer

Abstract

Belonging to power system area, the disclosed digital current synthesizer includes current transformation module (CTM), data acquisition module (DAM), data processing module (DPM), power amplification module (PAM), and guidance wire way out module (GWWM). Connected relation of these modules is as following: CTM converts signal of three-phase current from current transformer to signal of voltage outputted to DAM; processing the collected signal to digital signal in real time rapidly, DAM transfers the process data to the DPM; after obtaining corresponding synthesized current value in single phase, the DPM sends the value to D / A conversion module to convert it to analog signal sent to PAM; amplifying the signal, PAM through GWWM inputs the amplified signal to metal guidance wire. The invention applies microcomputer differential protective system (DPS) to guidance wire channel, and makes compatibility between disclosed and traditional DPS at area to be protected possible.

Description

Technical field [0001] The invention belongs to the field of power systems, in particular to a digital current synthesizer used in conjunction with microcomputer differential protection for transmission lines. Background technique [0002] Due to its high sensitivity, good selectivity, simplicity and reliability, differential protection is one of the most important relay protection methods in power systems. Its working principle is: the protection device synchronously collects the current at both ends of the protected line, runs the protection algorithm and judges whether a fault occurs and whether the fault point is located in the protected line, so as to determine whether the exit trips. Therefore, the normal operation of the differential protection must rely on the communication channel. [0003] Traditional differential protection is mainly composed of electromagnetic, transistor or integrated circuit differential relays, and supporting metal guide wire communication ch...

AI Technical Summary

Problems solved by technology

However, since only two guide wires are usually erected in the actual system to reduce investment costs, the three-phase current must first be integrated into a single-phase current and then fed into the guide wire. The existing protection devices still pass through the traditional current synthesizer— —Three-phase / single-phase converter to complete this function

This kind of traditional converter generally can only realize simple addition and subtraction of current, and the change of the wiring mode of the primary side winding is cumbersome and cannot be flexibly set, so that this type of microcomputer guide wire differential protection device cannot fully utilize digital technology The advantages

Images