CN102737138A - Estimation method and estimation system based on short-circuit current distribution for transformer short-circuit damage probability - Google Patents

Abstract

The invention provides an estimation method based on short-circuit current distribution for a transformer short-circuit damage probability. The method comprises the following steps of: step S1, modelling via a function distribution simulation unit in a processor to obtain a short-circuit current occurrence probability function fshort (I), and setting a transformer short-circuit damage cumulative failure probability function F(I) with to-be-solved parameters; step S2, obtaining the function distribution containing unknown parameters of a failure rate R via simulation calculation according to a failure probability definition; and step S3, obtaining a transformer short-circuit damage statistic failure rate H via multiple times of detection, and obtaining the values of the unknown parameters via processing for the statistic failure rate H according to the proportional relationship between the transformer short-circuit damage failure rate R and the statistic failure rate H, thus finally estimating out the transformer short-circuit damage probability. The invention further provides an estimation system based on short-circuit current distribution for the transformer short-circuit damage probability. Via the estimation method and the estimation system based on short-circuit current distribution for the transformer short-circuit damage probability provided by the invention, the estimation efficiency is increased, and the accurate failure probability data are obtained.

Description

Transformer short-circuit probability of damage evaluation method and system based on the short-circuit current distribution

[technical field]

The present invention relates to the power technology field, especially relate to a kind of transformer short-circuit probability of damage evaluation method and system that distributes based on short-circuit current.

[background technology]

In the large scale electrical power unit operational process; Transformer short-circuit damages principal element common in transformer fault; Therefore estimate the transformer short-circuit probability of damage in the time of need and safeguarding in design, so that the data technique support is provided for equipment maintenance and management and replacing.

For a long time; Existing transformer short-circuit probability of damage evaluation method all is mainly to start with from design, fault detect aspect; And transformer equipment is not damaged factor and operation of power networks is closely connected; Cause transformer short-circuit probability of damage estimation distortion, estimation efficient is lower, thereby is difficult to the quantification administrative skill support for equipment.

[summary of the invention]

The technical matters that the present invention will solve is; To prior art transformer short-circuit probability of damage evaluation method efficient and the lower defective of accuracy rate; A kind of transformer short-circuit probability of damage evaluation method and system that distributes based on short-circuit current is provided; To improve estimation efficient, obtain probability of malfunction data accurately.

In order to solve the problems of the technologies described above, the present invention provides a kind of transformer short-circuit probability of damage evaluation method that distributes based on short-circuit current, said method comprising the steps of:

Step S1: the function distribution simulation unit modeling through in the processor obtains short-circuit current probability of happening function f _Short(I) and set transformer short-circuit and damage accumulative total probability of malfunction function F (I);

Step S2: distribute through the function that analog computation obtains failure rate R according to probability of malfunction definition

, wherein function distributes and contains unknown parameter;

Step S3: obtain transformer short-circuit through repeated detection and damage statistics failure rate H; Damage the relation that failure rate R is directly proportional with statistics failure rate H according to transformer short-circuit; Obtain said unknown parameter value through statistics failure rate H processing, thereby finally estimate the transformer short-circuit probability of damage.

Further, in above-mentioned transformer short-circuit probability of damage evaluation method, among the said step S1,

Short-circuit current probability of happening function

Accumulative total probability of malfunction function

Wherein, m, θ, I ₀Be Weibull to be separated three parameters.

Further, in above-mentioned transformer short-circuit probability of damage evaluation method, said step S3 specifically comprises:

Choose parameter area according to statistics repeatedly;

The short-circuit current distribution value is adopted a fixed step size, set up a plurality of parameters equation to be separated;

Choose objective function according to said equation and simulate, its optimal objective function corresponding parameters is the parameter value of being asked to be separated.

Further, in above-mentioned transformer short-circuit probability of damage evaluation method, said a plurality of parameters equation to be separated of setting up is specially:

Damage failure rate R according to transformer short-circuit and can know the statistics failure rate with the relation that statistics failure rate H is directly proportional

$H=\mathrm{KR}=K\underset{{\mathrm{<figure-callout\; id="0"\; label="I"\; filenames="HDA0000055603270000021.png"\; state="\{\{state\}\}">I</figure-callout>}}_0}{\overset{\&infin;}{\&Integral;}}{f}_{\mathrm{short}}\left(I\right)*F\left(I\right)\mathrm{dI}=K\underset{{\mathrm{<figure-callout\; id="0"\; label="I"\; filenames="HDA0000055603270000021.png"\; state="\{\{state\}\}">I</figure-callout>}}_0}{\overset{\&infin;}{\&Integral;}}{\left(\frac{m}{\mathrm{\&theta;}}\right)}^{m-1}\exp [-{\left(\frac{I-{\mathrm{<figure-callout\; id="0"\; label="I"\; filenames="HDA0000055603270000021.png"\; state="\{\{state\}\}">I</figure-callout>}}_0}{\mathrm{\&theta;}}\right)}^m]\{1-\exp [-{\left(\frac{I-{\mathrm{<figure-callout\; id="0"\; label="I"\; filenames="HDA0000055603270000021.png"\; state="\{\{state\}\}">I</figure-callout>}}_0}{\mathrm{\&theta;}}\right)}^m\left]\right\}\mathrm{dI}$

Wherein, K is a scale-up factor, m, θ, I ₀Be Weibull to be separated three parameters.

The present invention also provides a kind of transformer short-circuit probability of damage estimating system that distributes based on short-circuit current, and it is characterized in that: said system comprises:

The processor modeling unit is used for the function distribution simulation unit modeling through processor, obtains short-circuit current probability of happening function f _Short(I) and set transformer short-circuit and damage accumulative total probability of malfunction function F (I);

The processor computing unit, the failure rate R function that is used for obtaining containing through analogue computer unknown parameter distributes;

Short circuit probability of damage evaluation unit is used for damaging the relation that failure rate R is directly proportional with statistics failure rate H according to transformer short-circuit, handles obtaining said unknown parameter value through statistics failure rate H, thereby finally estimates the transformer short-circuit probability of damage.

Further, in above-mentioned transformer short-circuit probability of damage estimating system, said short circuit probability of damage evaluation unit further comprises:

The selection of parameter subelement is used for choosing parameter area according to statistics repeatedly;

Subelement to be solved an equation is used for the short-circuit current distribution value is adopted a fixed step size, sets up a plurality of parameters equation to be separated;

The calculation of parameter subelement is used for choosing objective function according to said equation and simulates, and obtains the parameter value of being asked to be separated.

The transformer short-circuit probability of damage evaluation method and the system that the present invention is based on the short-circuit current distribution have improved estimation efficient, and have obtained probability of malfunction data more accurately.

[description of drawings]

To combine accompanying drawing and embodiment that the present invention is described further below, in the accompanying drawing:

Fig. 1 is the schematic flow sheet that the present invention is based on the transformer short-circuit probability of damage evaluation method of short-circuit current distribution;

Fig. 2 is that short-circuit current probability of happening and the short circuit among Fig. 1 damages the distribution statistics figure that adds up probability of malfunction;

Fig. 3 is that the transformer short-circuit among Fig. 1 damages statistics failure rate distribution statistics figure;

Fig. 4 is that Fig. 1 finds the solution the transformer short-circuit damage probability of malfunction scatter chart that obtains;

Fig. 5 is the synoptic diagram that the present invention is based on the preferred embodiment of the transformer short-circuit probability of damage estimating system that short-circuit current distributes.

[embodiment]

There is not factor in the existing transformer short-circuit probability of damage evaluation method with operation of power networks; Cause transformer short-circuit probability of damage estimation distortion; Estimation efficient is lower; The transformer short-circuit that the transformer short-circuit probability of damage evaluation method that distributes based on short-circuit current of the present invention is simulated based on short-circuit current through the Weibull distribution of three parameters damages probability of malfunction, thereby has improved estimation efficient, and has obtained probability of malfunction data more accurately.

See also Fig. 1, Fig. 1 is the schematic flow sheet that the present invention is based on the transformer short-circuit probability of damage evaluation method of short-circuit current distribution.Said method comprising the steps of:

Step S1: the function distribution simulation unit modeling through in the processor obtains short-circuit current probability of happening function f _Short(I) and set transformer short-circuit and damage accumulative total probability of malfunction function F (I);

In the present embodiment, select for use the Weibull distribution of three parameters to simulate short-circuit current probability of happening function f based on short-circuit current _Short(I) and transformer short-circuit damage probability of malfunction function F (I), promptly

Short-circuit current probability of happening function

Accumulative total probability of malfunction function

Wherein, m, θ, I ₀Be Weibull to be separated three parameters.

Step S2: distribute through the function that analog computation obtains failure rate R according to probability of malfunction definition

, wherein function distributes and contains unknown parameter.

Failure rate R does in the present embodiment

Wherein, m, θ, I ₀Be unknown parameter to be separated.

Step S3: obtain transformer short-circuit through repeated detection and damage statistics failure rate H; Damage the relation that failure rate R is directly proportional with statistics failure rate H according to transformer short-circuit; Obtain said unknown parameter value through statistics failure rate H processing, thereby finally estimate the transformer short-circuit probability of damage.

Definition according to failure rate; Transformer short-circuit damages failure rate

, and it is directly proportional with transformer short-circuit damage statistics failure rate H, and both scale-up factors can be considered the short circuit incidence.

See also Fig. 2, Fig. 2 is that short-circuit current probability of happening and the short circuit among Fig. 1 damages the distribution statistics figure that adds up probability of malfunction.Wherein, short-circuit current probability of happening distribution curve f _Short(I) and short circuit damage area that accumulative total probability of malfunction distribution curve F (I) and transverse axis short-circuit current nargin surrounds and be transformer short-circuit and damage failure rate R, its with add up failure rate H and be directly proportional.

See also Fig. 3, Fig. 3 is that Fig. 3 is the transformer short-circuit damage statistics failure rate distribution statistics figure among Fig. 1.Its transverse axis be short-circuit current distribution (short-circuit current or rated short circuit current) square, the longitudinal axis is that transformer short-circuit damages the statistics failure rate.

Estimation process specifically comprises among the said step S3:

Step S31: choose parameter area according to statistics repeatedly;

This step is the technical experience according to present technique field personnel, estimates and chooses certain parameter area, promptly excludes and does not obviously meet actual parameter value.

Step S32: the short-circuit current distribution value is adopted a fixed step size, set up a plurality of parameters equation to be separated;

Damage failure rate R according to transformer short-circuit and can know the statistics failure rate with the relation that statistics failure rate H is directly proportional

$H=\mathrm{KR}=K\underset{{\mathrm{<figure-callout\; id="0"\; label="I"\; filenames="HDA0000055603270000021.png"\; state="\{\{state\}\}">I</figure-callout>}}_0}{\overset{\&infin;}{\&Integral;}}{f}_{\mathrm{short}}\left(I\right)*F\left(I\right)\mathrm{dI}=K\underset{{\mathrm{<figure-callout\; id="0"\; label="I"\; filenames="HDA0000055603270000021.png"\; state="\{\{state\}\}">I</figure-callout>}}_0}{\overset{\&infin;}{\&Integral;}}{\left(\frac{m}{\mathrm{\&theta;}}\right)}^{m-1}\exp [-{\left(\frac{I-{\mathrm{<figure-callout\; id="0"\; label="I"\; filenames="HDA0000055603270000021.png"\; state="\{\{state\}\}">I</figure-callout>}}_0}{\mathrm{\&theta;}}\right)}^m]\{1-\exp [-{\left(\frac{I-{\mathrm{<figure-callout\; id="0"\; label="I"\; filenames="HDA0000055603270000021.png"\; state="\{\{state\}\}">I</figure-callout>}}_0}{\mathrm{\&theta;}}\right)}^m\left]\right\}\mathrm{dI}$

Wherein, K is a scale-up factor, m, θ, I ₀Be Weibull to be separated three parameters.

Damage statistics failure rate distribution statistics according to the transformer short-circuit among Fig. 3, the short-circuit current distribution value is adopted a fixed step size, can set up a plurality of about m, θ, I ₀Wait to separate the equation of parameter.

Step S33: choose objective function according to said equation and simulate, its optimal objective function corresponding parameters is the parameter value of being asked to be separated.

Can get m, θ, I through Fig. 3 calculating in the present embodiment ₀Three parameters are respectively 0.35,9.96 and 0.6.

As shown in Figure 4, Fig. 4 damages the scatter chart that probability of malfunction changes with different electric current nargin for finding the solution the transformer short-circuit that obtains in the present embodiment.

See also Fig. 5, Fig. 5 is the synoptic diagram that the present invention is based on the transformer short-circuit probability of damage estimating system preferred embodiment of short-circuit current distribution.

Said estimating system comprises:

Processor modeling unit 10 is used for the function distribution simulation unit modeling through processor, obtains short-circuit current probability of happening function f _Short(I) and set transformer short-circuit and damage accumulative total probability of malfunction function F (I);

Processor computing unit 20, it is connected in processor modeling unit 10, and the failure rate R function that is used for obtaining containing through analogue computer unknown parameter distributes;

Short circuit probability of damage evaluation unit 30 is used for damaging the relation that failure rate R is directly proportional with statistics failure rate H according to transformer short-circuit, handles obtaining said unknown parameter value through statistics failure rate H, thereby finally estimates the transformer short-circuit probability of damage.

Wherein, short circuit probability of damage evaluation unit 30 further comprises:

Selection of parameter subelement 301 is used for choosing parameter area according to statistics repeatedly;

The subelement 302 of waiting to solve an equation is used for the short-circuit current distribution value is adopted a fixed step size, sets up a plurality of parameters equation to be separated;

Calculation of parameter subelement 303 is used for choosing objective function according to said equation and simulates, and obtains the parameter value of being asked to be separated.

Than prior art, the present invention is based in the transformer short-circuit probability of damage evaluation method and system of short-circuit current distribution, improve estimation efficient, and obtained probability of malfunction data more accurately.

The above embodiment has only expressed several kinds of embodiments of the present invention, and it describes comparatively concrete and detailed, but can not therefore be interpreted as the restriction to claim of the present invention.Should be pointed out that for the person of ordinary skill of the art under the prerequisite that does not break away from the present invention's design, can also make some distortion and improvement, these all belong to protection scope of the present invention.Therefore, the protection domain of patent of the present invention should be as the criterion with accompanying claims.

Claims (6)

1. transformer short-circuit probability of damage evaluation method that distributes based on short-circuit current is characterized in that: said method comprising the steps of:

Step S1: the function distribution simulation unit modeling through in the processor obtains short-circuit current probability of happening function f _Short(I) and set transformer short-circuit and damage accumulative total probability of malfunction function F (I);

Step S2: distribute through the function that analog computation obtains failure rate R according to probability of malfunction definition , wherein function distributes and contains unknown parameter;

Step S3: obtain transformer short-circuit through repeated detection and damage statistics failure rate H; Damage the relation that failure rate R is directly proportional with statistics failure rate H according to transformer short-circuit; Obtain said unknown parameter value through statistics failure rate H processing, thereby finally estimate the transformer short-circuit probability of damage.

2. method according to claim 1 is characterized in that: among the said step S1,

Short-circuit current probability of happening function

Accumulative total probability of malfunction function

Wherein, m, θ, I ₀Be Weibull to be separated three parameters.

3. method according to claim 1 is characterized in that: said step S3 specifically comprises:

Choose parameter area according to statistics repeatedly;

The short-circuit current distribution value is adopted a fixed step size, set up a plurality of parameters equation to be separated;

Choose objective function according to said equation and simulate, its optimal objective function corresponding parameters is the parameter value of being asked to be separated.

4. method according to claim 3 is characterized in that: said a plurality of parameters equation to be separated of setting up is specially:

Damage failure rate R according to transformer short-circuit and can know the statistics failure rate with the relation that statistics failure rate H is directly proportional

$H=\mathrm{KR}=K\underset{I_0}{\overset{\&infin;}{\&Integral;}}{f}_{\mathrm{short}}\left(I\right)*F\left(I\right)\mathrm{dI}=K\underset{I_0}{\overset{\&infin;}{\&Integral;}}{\left(\frac{m}{\mathrm{\&theta;}}\right)}^{m-1}\exp [-{\left(\frac{I-I_0}{\mathrm{\&theta;}}\right)}^m]\{1-\exp [-{\left(\frac{I-I_0}{\mathrm{\&theta;}}\right)}^m\left]\right\}\mathrm{dI}$

Wherein, K is a scale-up factor, m, θ, I ₀Be Weibull to be separated three parameters.

5. transformer short-circuit probability of damage estimating system that distributes based on short-circuit current, it is characterized in that: said system comprises:

The processor modeling unit is used for the function distribution simulation unit modeling through processor, obtains short-circuit current probability of happening function f _Short(I) and set transformer short-circuit and damage accumulative total probability of malfunction function F (I);

The processor computing unit, the failure rate R function that is used for obtaining containing through analogue computer unknown parameter distributes;

Short circuit probability of damage evaluation unit is used for damaging the relation that failure rate R is directly proportional with statistics failure rate H according to transformer short-circuit, handles obtaining said unknown parameter value through statistics failure rate H, thereby finally estimates the transformer short-circuit probability of damage.

6. probability of damage estimating system according to claim 5 is characterized in that: said short circuit probability of damage evaluation unit further comprises:

The selection of parameter subelement is used for choosing parameter area according to statistics repeatedly;

Subelement to be solved an equation is used for the short-circuit current distribution value is adopted a fixed step size, sets up a plurality of parameters equation to be separated;

The calculation of parameter subelement is used for choosing objective function according to said equation and simulates, and obtains the parameter value of being asked to be separated.

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