A kind of AC bus differential protection method

A technology of AC busbar and differential protection, applied in the direction of emergency protection circuit devices, electrical components, etc., can solve problems such as differential protection, and achieve the effect of accurately judging faults

CN104092191BActive Publication Date: 2016-11-30STATE GRID CORP OF CHINA +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2016-11-30

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Abstract

The invention relates to an AC bus differential protection method, which belongs to the technical field of flexible direct current transmission. The present invention proposes an AC bus differential protection method aiming at the topological structure of connecting the AC bus on the variable valve side in parallel with three-phase reactors and the configuration of its measuring points. Then calculate the current of each phase of the grounding reactor according to the grounding resistance and the actual parameters of the reactor; calculate the difference based on the collected current of each phase on the valve side, the current of each phase on the valve side of the starting circuit and the calculated current of each phase of the grounding reactor The absolute value of the current; judge whether the current difference is greater than the protection setting value, if greater, start the AC bus differential protection. The invention can quickly and accurately judge faults and effectively protect the whole system.
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Description

technical field

[0001] The invention relates to an AC bus differential protection method, which belongs to the technical field of flexible direct current transmission. Background technique

[0002] The AC bus area on the side of the connecting variable valve is an important part of the flexible DC transmission system. The AC bus differential protection is the main protection for faults in this area, and realizes the protection function in case of grounding or short-circuit faults in the area. There are few actual projects of flexible DC transmission, and the topological structure is quite different, and there is no detailed description of AC bus differential protection. Contents of the invention

[0003] The purpose of the present invention is to provide a differential protection method for an AC bus to solve the problem of differential protection of a topological structure that is grounded by a resistance after connecting the AC bus on the variable valve side in parallel ...

Examples

Embodiment Construction

[0020] The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

[0021] The present invention is aimed at the topological structure and its measuring point configuration after connecting the parallel three-phase reactor of the AC bus on the variable valve side and the configuration of its measuring points. figure 1 shown. The area of ​​AC bus differential protection is as follows: figure 1 The area in the middle box; the measuring point used for the differential protection of the AC bus is the voltage value U of each phase on the valve side acD_A / B / C , the total current value of the grounding resistance I GND , to connect the current IVD of each phase on the variable valve side A / B / C , the current IVC of each phase on the valve side of the starting circuit A / B / C . The realization method of the AC bus differential protection of the present invention comprises the following steps:

[0022] 1. The meas...