A Method for Obtaining the Attenuation Time Constant of DC Component of Unsymmetrical Short-Circuit Current

A technology for decaying time constant and DC component, applied in the field of power system, can solve the problem that the DC component of short-circuit current is not mentioned, and achieve the effect of reducing the amount of calculation and simplifying the modeling.

Active Publication Date: 2019-08-16
SHANGHAI UNIVERSITY OF ELECTRIC POWER
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the practical calculation of the DC component of the short-circuit current in power system asymmetrical short-circuit is not mentioned in various standards as well as in various literatures

Method used

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  • A Method for Obtaining the Attenuation Time Constant of DC Component of Unsymmetrical Short-Circuit Current
  • A Method for Obtaining the Attenuation Time Constant of DC Component of Unsymmetrical Short-Circuit Current
  • A Method for Obtaining the Attenuation Time Constant of DC Component of Unsymmetrical Short-Circuit Current

Examples

Experimental program
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Effect test

Embodiment

[0098] Press as Figure 5 As shown in the system wiring diagram, the asymmetrical fault simulation experiment is carried out on the EMTP software. The DC component is separated from the simulation results under different fault conditions, and then its decay time constant is fitted, which is used as a comparison value of the theoretical calculation value in this paper to test the correctness and adaptability of the method in this paper.

[0099] The main parameters of the components are as follows:

[0100] Secluded pole machine: Xd″=Xq″=0.143, Xd=Xq=1.9323, Ra=0.002, Sn=600MVA, the negative sequence parameters of the motor are the same as the positive sequence parameters.

[0101] Salient pole machine 1: Xd″=0.24, Xq″=1.04Xd″, Xd=0.86, Xq=0.58, Ra=0.004, Sn=600MVA, the negative sequence parameters of the motor are the same as the positive sequence parameters.

[0102] Salient pole machine 2: Xd″=0.24, Xq″=1.5Xd″, Xd=0.86, Xq=0.58, Ra=0.004, Sn=600MVA, the negative sequence p...

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Abstract

The invention relates to an asymmetric short circuit current DC component decaying time constant acquisition method. The method comprises the following steps: 1) according to the type of asymmetric short circuit fault happening to a power system, a 120 composite sequence network formed by a 1 sequence network, a 2 sequence network and a 0 sequence network is built correspondingly; 2) according to the connection relationship of the 120 composite sequence network, the decaying time constant of a DC component in the short circuit current is calculated. Compared with the prior art, the method has the advantages of simple modeling, high calculation precision, wide applicability and the like.

Description

technical field [0001] The invention relates to the field of power systems, in particular to a method for acquiring the decay time constant of a DC component of an asymmetric short-circuit current. Background technique [0002] With the development of the power system and people's pursuit of energy saving and consumption reduction, my country's power system is constantly developing to a higher voltage level and a larger scale. In order to reduce the loss, the reactance-resistance ratio of the main primary components such as generators, transformers, and transmission lines is getting larger and larger, resulting in slower and slower attenuation of the DC component in the short-circuit current of the system. The series reactance and high impedance used to limit the short-circuit current Transformers exacerbate the problem. However, the calculation of the attenuation of the DC component of the short-circuit current has been short of simple and practical methods and tools in en...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01R31/00G01R31/02
CPCG01R31/00G01R31/50
Inventor 曹炜周明陈春阳侯亚文
Owner SHANGHAI UNIVERSITY OF ELECTRIC POWER
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