A detection method of line selection device based on rtds with small disturbance method

Abstract

The invention belongs to the technical field of power system line selection function testing, and specifically relates to a detection method of a small disturbance method line selection device based on RTDS. The invention builds a simulation model according to the actual parameters of the substation on site, and builds different fault situations in the simulation model , so that the built simulation model can output the corresponding current signal and voltage signal according to different ground fault conditions, and output the fault voltage and current in line with the actual site through the RTDS signal channel to the power amplifier for amplification processing, small disturbance method fault line selection device detection The received amplified signal is fed back to the simulation model through the closed-loop RTDS signal channel to adjust the compensation degree, and the small disturbance method fault line selection device realizes fault line selection according to the signal change amount; the invention can select the small disturbance method fault line in the distribution network The line device is tested, and an accurate judgment is made on the line selection ability of the line selection device.

Description

technical field [0001] The invention belongs to the technical field of line selection function testing of electric power systems, and mainly relates to a test scheme for a single-phase ground fault line selection device of a small current grounding system, in particular to a detection method for a line selection device based on an RTDS small disturbance method. Background technique [0002] Indirect grounding system is commonly used in medium and low voltage distribution networks in my country. Its main advantage is that only a small zero-sequence current will be generated in the system when a single-phase ground fault occurs, and the three-phase line voltage can still maintain symmetry. Affect the normal operation of the system, and can continue to run for 1-2h under single-phase ground fault. However, when the distribution network system continues to operate under a single-phase ground fault, the single-phase ground phase voltage drops to zero, while the non-fault phase vol...

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Problems solved by technology

However, when the distribution network system continues to operate under a single-phase ground fault, the single-phase ground phase voltage drops to zero, while the non-fault phase voltage rises to three times the square root of normal operation, and long-term operation under fault conditions leads to The rising voltage will break down the weak part of the non-faulty phase insulation, resulting in a two-phase grounding short circuit fault or a three-phase short circuit. The reliability of the power grid operation; however, the current small current grounding line selection device cannot accurately select the fault line due to reasons such as the fault current is not obvious, and there has been no reasonable detection method to detect the line selection device due to technical reasons , and determine its line selection ability, it is more difficult to detect its line selection ability for small disturbance method fault line selection devices that require closed-loop feedback. The grounding line selection device is used for testing, and the test scheme is designed on a recognized platform, which makes it have a certain degree of recognition in the industry

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