Characteristic parameter calculation method and device

A technology of characteristic parameter and calculation method, applied in the field of characteristic parameter calculation method and device, can solve problems such as calculation deviation of characteristic parameter of short-circuit current DC component

Active Publication Date: 2019-01-01
NORTHWEST BRANCH OF STATE GRID POWER GRID CO +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] In view of this, the present application provides a method and device for calculating characteristic parameters, which are used to solve the probl...

Method used

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  • Characteristic parameter calculation method and device
  • Characteristic parameter calculation method and device
  • Characteristic parameter calculation method and device

Examples

Experimental program
Comparison scheme
Effect test

no. 1 example

[0030] See figure 1 , figure 1 A schematic flowchart of a method for calculating characteristic parameters provided by the present application is shown. As shown in the figure, a method for calculating characteristic parameters provided by the present application includes:

[0031] Step S100: According to the short-circuit current waveform data changing with time on the time axis, define a first discrete function;

[0032] Wherein, it should be noted that the first discrete function, for example, defines the short-circuit current waveform data as a discrete function that changes with time on the time axis, marked as i(t).

[0033] Step S200: Define a second discrete function according to the integral definition or difference of the first discrete function, and the second discrete function takes a value in a time domain interval;

[0034] Wherein, it should be noted that, the second discrete function, for example: the numerical integration of i(t) over the time domain interval...

Embodiment approach

[0059] For ease of understanding, two implementations of the characteristic parameter calculation method are introduced below:

[0060] The first implementation of the two implementations of the characteristic parameter calculation method is the calculation method of the characteristic parameter of the DC component of the short-circuit current of the power system based on the integral method. The first implementation in the two implementations of the characteristic parameter calculation method includes the following steps:

[0061] 1) Define the short-circuit current waveform data as a discrete function i(t) that changes with time on the time axis, and define the numerical integration of i(t) in the time domain interval [t, t+T] as a discrete function g(t) ,which is:

[0062]

[0063] 2) Take g(t) in the time domain t 1 , t 2 The value of time g(t 1 ), g(t 2 ) Simultaneous equations:

[0064]

[0065] 3) By solving the above formula, the time constant τ and the ini...

no. 2 example

[0075] See image 3 , image 3 A schematic flowchart of another characteristic parameter calculation method provided by the present application is shown. The present application also provides a method for calculating characteristic parameters, including:

[0076] Step S400: According to the short-circuit current waveform data changing with time on the time axis, define a first discrete function;

[0077] Wherein, it should be noted that the first discrete function, for example: define the short-circuit current waveform data as a discrete function that changes with time on the time axis, marked as i(t), and the representation of i(t) is for example:

[0078] Step S500: Perform an integral operation on the first discrete function to obtain a third discrete function, and the third discrete function takes a value within a time domain interval;

[0079] Wherein, it should be noted that the integral operation is performed on the first discrete function to obtain the third discr...

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Abstract

The invention provides a characteristic parameter calculation method and device which are used to solve a problem that power system short circuit current direct current component characteristic parameter calculation has great deviation in the prior art. The characteristic parameter calculation method comprises the following steps of according to short-circuit current waveform data which is changedalong with time on an time axis, defining a first discrete function; defining or differentially defining a second discrete function according to a first discrete function integral, wherein the seconddiscrete function is evaluated in a time domain interval; and substituting the value of a first moment and the value of a second moment into the second discrete function to obtain a characteristic parameter, wherein the characteristic parameter includes a time constant and a direct current component initial value, the first moment is the moment in the time domain interval, and the second moment is the moment different from the first moment in the time domain interval.

Description

technical field [0001] The present application relates to the technical field of short-circuit faults in power systems, and relates to a method and device for calculating characteristic parameters. Background technique [0002] With the rapid development of the power system, the problem of excessive short-circuit capacity of the system has become more and more prominent, and the high-voltage reactance connected in series in the system has become an important measure to reduce the effective value of the short-circuit current. However, the high-voltage reactance in series increases the DC time constant of the system, causing the high-voltage AC circuit breaker to exceed its rated breaking capacity when breaking the asymmetrical short-circuit fault current. So far, the short-circuit calculation of the power system mainly focuses on the periodic component of the short-circuit current, and often does not pay much attention to the DC component and its attenuation law. Exceeding t...

Claims

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Application Information

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IPC IPC(8): G01R31/02G06F17/10G06K9/00
CPCG06F17/10G01R31/50G06F2218/10
Inventor 张文朝高享想王蒙曹生顺汪莹杨俊炜
Owner NORTHWEST BRANCH OF STATE GRID POWER GRID CO
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