Method and device for obtaining optimal parameters of direct-current transmission system current limiter

Abstract

The embodiment of the invention provides a method and device for obtaining the optimal parameters of a direct-current transmission system current limiter, wherein the method comprises the steps of firstly carrying out fault analysis on a DC power transmission system comprising a current limiter, and obtaining a fault current model; establishing a mathematical model of the superconducting current limiter according to the superconducting characteristics of the superconducting current limiter, wherein the mathematical model comprises a resistance model and a thermal model; then, according to themathematical model and the fault current model of the superconducting current limiter, obtaining an optimal configuration model of the current limiter in the direct current system; and finally, obtaining the optimal parameters of the current limiter according to the optimal configuration model of the current limiter. The optimal parameters obtained by adopting the above scheme can effectively reduce the maximum fault removal capacity of a direct-current circuit breaker, increase the fault response time of the system, ensure the correctness and reliability of the action of the direct-current circuit breaker, and the method and the device have important significance for the direct-current power transmission system.

Description

technical field [0001] The present application relates to the technical field of direct current transmission technology, in particular to a method and device for obtaining optimal parameters of a current limiter in a direct current transmission system. Background technique [0002] DC transmission technology has the advantages of independent control of active power and reactive power, and no risk of commutation failure. Therefore, DC transmission technology has a wide range of applications in new energy grid integration and regional grid interconnection. However, due to the small damping and response coefficient of the DC transmission system, when a short-circuit fault occurs on the DC side of the DC transmission system, the fault will develop rapidly, resulting in a short-circuit current that is more than ten times or even dozens of times the rated current of the system. Therefore, the rapid removal of faults on the DC side has become a difficult point in the research of DC...

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Problems solved by technology

[0003] At present, one of the main solutions for DC side faults is to configure converters and DC circuit breakers with fault isolation capabilities on the DC line, and converters with fault isolation functions will not only increase the construction cost of the converter station, but also require Blocking all converters in the DC network will affect the stable operation of the DC network, and because fault detection and the action of the DC circuit breaker take time, the fault current often has risen rapidly, which will make the requirements of the DC circuit breaker for the breaking capacity Further improvement, therefore, the application of DC circuit breakers is limited by the cut-off capacity, especially in multi-terminal DC transmission systems with complex capacitor discharge paths, which increases the design difficulty and cost of DC circuit breakers. Therefore, it is necessary to choose a suitable current limiting solution to avoid the above problems

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