Automatic test system of dc circuit breaker characteristic parameter

Abstract

The invention discloses an automatic testing system of characteristic parameters of a direct-current breaker, which consists essentially of an analyzing and managing system controlled by a computer, a digital storage oscillograph and a program-controllable direct-current power source. 12-bit digital values that are output by a single chip microcomputer output 0 to 5V voltage through a digital-to-analog converting circuit, and the voltage is output to a phase-shifting-control full-bridge zero-voltage switching and a pulse modulation converting circuit through an isolating amplifier as well as to an EA+ end of a main chip, thus changing output current. The electromagnetic tripping action time is measured by a waveform breaking method and taking the largest constant short-circuit current in electromagnetic instantaneous acting tripping as the starting point of timing, thus having the advantages of high accuracy, efficiency and reliability.

Description

technical field [0001] The invention relates to the automatic test of electric power engineering, the test of the protective action characteristic of the source of the tested DC circuit breaker and the verification of the level difference coordination of the DC power supply system. Background technique [0002] Due to the difference in protective action characteristics of different manufacturers or different series of DC circuit breakers of the same manufacturer, many leapfrog tripping accidents have been caused, causing voltage loss in the DC system of the whole station, and even causing vicious accidents in the power grid system. Therefore, it is extremely important to test and verify the protection and coordination characteristics of DC circuit breakers to prevent accident expansion and equipment damage. In order to accurately analyze the protection and coordination problems in the current substation DC system, it is necessary to carry out the short-circuit protection cha...

AI Technical Summary

Problems solved by technology

[0006] A switching power supply is used as a DC current source, and the maximum output current can reach 1000A, but the maximum output voltage is only 5V, so it can only carry out the overload ampere-second characteristic test due to the capacity limit

[0007] In the above schemes, the current range is small, the output power is small, the waveform parameters (amplitude, time constant) cannot be measured, the short-circuit current time constant cannot be adjusted, and the requirements of the national standards GB14048.2-2001 and GB10963.2-2003 cannot be fully met.

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