High-voltage direct current convertor station no-grounding operation protective tripping method

Abstract

Provided is a high-voltage direct current convertor station no-grounding operation protective tripping method. According to the method, when the convertor station is in a no-grounding operation mode, different protective tripping methods can be configured according to the characteristics of a double-pole ground operation mode and a single-pole metal loop operation mode. In the single-pole metal loop operation mode, when protective tripping is conducted on one pole, the protective tripping logic of the pole is executed; in the double-pole ground operation mode, when protective tripping is conducted on one pole, the protective tripping logic of the pole is executed, a protective tripping command of the pole is sent to the other pole, the protective tripping logic of the other pole is also executed, as a result, the shortest time different between tripping of the two poles can be guaranteed, the values of the currents flowing into a grounding grid from the two poles are minimized, and the safety of station equipment and operating crew is guaranteed.

Description

technical field [0001] The invention mainly relates to the field of high-voltage direct current transmission in electric power systems, in particular to a protection tripping method for a high-voltage direct current converter station without grounding pole operation. Background technique [0002] With the development of my country's electric power industry, the application of high-voltage direct current transmission technology in long-distance power transmission projects is becoming more and more extensive. With the China Southern Power Grid’s Yunnan-Guangdong ±800kV UHV DC Project in June 2010 and the State Grid’s Xiangjiaba-Shanghai ±800kV UHVDC Project in July 2010, my country has become the country with the highest voltage level in the world, transmission The country with the largest capacity and the most advanced UHV DC transmission project. [0003] The HVDC power transmission project consists of a rectifier converter station, a DC line, and an inverter converter stati...

AI Technical Summary

Problems solved by technology

However, if the grounding grid in the converter station is used instead of the DC grounding pole for operation, the vector sum of the two-pole grounding current vectors is about 0 in the double-pole operation mode, and no current will flow into the grounding grid in the station. When the DC protection trip of one pole causes this After one pole DC is out of service, the ground current of the other pole will directly flow into the grounding grid in the station, which seriously threatens the safety of equipment and operators in the station. It will not threaten the safety of operating personnel and equipment, so the existing DC project can only use single-pole metal return line operation when the converter station operates without a ground electrode, and the transmission power is limited

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