CN104346536B - A kind of primary cut-out refuses the determination method of point probability of malfunction - Google Patents

Abstract

The invention discloses a kind of determination method that primary cut-out refuses point probability of malfunction, including S100：Acquisition causes primary cut-out to refuse the Probability p that each failure factor of point failure occurs₁, p₂, p₃..., p_n；S200：The weight of each failure factor is calculated using the method for Uncertainty number；S300：Calculate the normalized weight of each failure factor；S400：The probability and weight occurred according to each failure factor, calculate primary cut-out and refuse a point probability of malfunction.Amount of calculation of the present invention is smaller, simple to operate.

Description

A kind of primary cut-out refuses the determination method of point probability of malfunction

Technical field

The present invention relates to power equipment, more particularly to a kind of primary cut-out refuses the determination method of point probability of malfunction.

Background technology

Due to being influenceed by various unfavorable factors in primary cut-out work, and its operational motion process is quite multiple It is miscellaneous, be easy to break down, such as refuse point.Breaker is controlled in relay protection and automatic safety device action or operating process Switch sends in the case of instruction refusal, and separately action is referred to as breaker and refuses point.Once there is primary cut-out to refuse point not only to cause The power outage of large area, or even personal safety is threatened, bring and have a strong impact on.Therefore, point failure of refusing to breaker carries out depth The understanding for entering, the probability of happening that research primary cut-out refuses point failure is necessary.The present invention intends by calculating breaker The method of the importance degree of different faults is so as to realize the calculating of circuit breaker failure probability.The current computational methods master on importance degree There are Grey Incidence, analytic hierarchy process (AHP) etc..Grey Incidence is easily because policymaker goes out to the subjective value difference of resolution ratio The diversity of existing result of calculation, the selection with reference to sequence is also one of difficult point；Analytic hierarchy process (AHP) applies to more evaluation and refers to During mark number, fuzzy Judgment is easily produced, make uncertain increase, the judgment matrix for being given is difficult to meet coherence request, while Evaluation conclusion to each expert is set up judgment matrix and is checked, and amount of calculation is larger.

The content of the invention

For defect present in prior art, the present invention provides a kind of primary cut-out and refuses a point determination side for probability of malfunction Method.

A kind of primary cut-out refuses the determination method of point probability of malfunction, comprises the following steps：

S100：Acquisition causes primary cut-out to refuse the Probability p that each failure factor of point failure occurs₁, p₂, p₃..., p_n；

S200：The weight of each failure factor is calculated using the method for Uncertainty number；

Be provided with m expert carries out Assessment of Important to n index for triggering breaker to refuse point failure, and m is obtained by evaluating Position expert obtains the importance Uncertainty number of index j on the n estimate of index：

In formula, A represents Uncertainty number, [x₁, x_k] it is index importance interval,It is index importance value Confidence level distribution density function.α_iImportance value corresponding to index j is x_iNormalization reliability and, k for failure type Number.x_iIt is a certain value of index weight；

Calculate the mathematical expectation E (A of the Uncertainty number_j), formula is as follows：

E (A) is single order Uncertainty number, wherein α=a₁+α₂+…+α_k,The as weighted value of index j；

S300：Calculate the normalized weight of each failure factor；

S400：The probability and weight occurred according to each failure factor, calculate primary cut-out and refuse a point probability of malfunction；

P=p₁×ω₁+p₂×ω₂+…+p_n×ω_n。

Compared with prior art, a technical scheme in above-mentioned technical proposal has advantages below or beneficial effect：This Invent propose Uncertainty number method, represented by the way of confidence level present in circuit breaker failure it is many it is uncertain because Element, will not produce the omission and distortion of information, can comprehensively reflect actual conditions, and amount of calculation is smaller, simple to operate, tool There is practicality higher；The present invention is proposed and calculates the method that primary cut-out refuses point probability of malfunction using Uncertainty number. The method represents many uncertain factors present in circuit breaker failure by the way of confidence level, will not produce the something lost of information Leakage and distortion, can comprehensively reflect actual conditions, and amount of calculation is smaller, simple to operate, with practicality higher.

Brief description of the drawings

Fig. 1 is the flow chart present invention determine that method.

Specific embodiment

With reference to Fig. 1, the present invention is expanded on further.It should be understood that these embodiments be merely to illustrate the present invention and without In limitation the scope of the present invention.In addition, it is to be understood that after the content for having read instruction of the present invention, those skilled in the art can be with The present invention is made various changes or modifications, these equivalent form of values equally fall within the model that the application appended claims are limited Enclose.

Primary cut-out of the invention refuses the determination method of point probability of malfunction, and high pressure open circuit is calculated using Uncertainty number Device refuses a point probability of malfunction, and many uncertain factors present in circuit breaker failure are represented by the way of confidence level, refuses a point event Hinder comprising the following steps that for determine the probability：

S100：Acquisition causes primary cut-out to refuse the probability that each failure factor of point failure occurs.

The failure factor for causing primary cut-out to be refused point has various, can specifically be divided into two classes：Mechanical factor and it is electric because Element.Wherein mechanical factor mainly includes：Contact welding, mechanism's clamping stagnation, the mechanical failure of rotation, pin come off or spring mechanical iron core Block；Electricabsorption agent mainly includes：Tight, malposition and equipment itself do not go wrong for wiring, such as coil burnout, Resistance burns.

The running environment of primary cut-out is refused a point failure and is had a major impact for primary cut-out, and for example longtime running is in wet The probability that primary cut-out in thermal environment occurs mechanical breakdown is higher, and longtime running is in spread of voltage environment Primary cut-out its occur electric fault probability it is higher.Accordingly, can be determined according to local practical operation situation each The Probability p that failure factor occurs₁, p₂, p₃..., p_n.Can be by counting the high pressure that a certain failure factor causes in a period of time Breaker refuses point number of stoppages and accounts for total primary cut-out to refuse the accounting of point number of stoppages to determine that it is general that each failure factor occurs Rate.It is 1 time for example by mechanism's clamping stagnation number of times in statistics a period of time, and this section of time inner high voltage breaker refuses a point number of stoppages It is 10 times, then can determines the Probability p of mechanism's clamping stagnation this failure factor generation₁It is 10%, can similarly determines other events The probability that barrier factor occurs.

S200：The weight of each failure factor is calculated using the method for Uncertainty number.

Specifically, in order to calculate the weight of each failure factor, first have to calculate the importance corresponding to each fault indices The normalization reliability of value and.Be provided with m expert carries out Assessment of Important to n index for triggering breaker to refuse point failure, leads to Cross evaluation and obtain m expert on the n estimate of index, the importance Uncertainty number of index j can be obtained：

In formula, A represents Uncertainty number, [x₁, x_k] it is index importance interval,It is index importance value Confidence level distribution density function.α_iImportance value corresponding to index j is x_iNormalization reliability and, k for failure type Number.3 kinds of different types of failure (x are for example given in table 1₁、x₂、x₃), k is referred to herein as 3, x_iAnd be index weight A certain value.

For example assessed for breaker mechanism clamping stagnation index importance, can respectively provide [x by three experts A, B, C₁, x₃] it is interval in certainty value under each importance degree, as shown in table 1.

The breaker mechanism clamping stagnation index importance of table 1 is assessed

Y in table₁₁-y₃₃Represent the certainty value under each importance degree that expert provides.A, B, C represent three experts.Then α_iMeter Operator expression formula is：

Calculate the mathematical expectation E (A of the Uncertainty number_j).Formula is as follows：

The unascertained number that is contemplated to be herein expects that what the x values at calculating were represented is exactly confidence level.

E (A) is single order Uncertainty number, wherein α=α₁+α₂+…+α_k,The as weighted value of index j. The weight that each failure factor can be obtained is：x₁, x₂..., x_n

S300：Calculate the normalized weight of each failure factor.

S400：The probability and weight occurred according to each failure factor, calculate primary cut-out and refuse a point probability of malfunction.

P=p₁×ω₁+p₂×ω₂+…+p_n×ω_n

By taking certain primary cut-out as an example, causing it to refuse a reason for point failure occurs has：Contact welding, mechanism's clamping stagnation, rotation Mechanical failure, pin come off.The probability such as table 1 that each failure factor occurs

The primary cut-out of table 1 refuses point failure cause and probability

Failure cause	Probability
		Contact is welded	0.24
Mechanism's clamping stagnation	0.26
		Rotate mechanical failure	0.33
Pin comes off	0.17

Method using Uncertainty number determines weight.By taking contact welding as an example.Expert is engaged to be given between 0~10 Contact welds the reliability distribution under index importance interval and respective value, as shown in table 2.

The welding index importance assessment of the contact of table 2

It is hereby achieved that the importance Uncertainty number confidence level distribution density function of contact welding index is：

The mathematic expectaion that Uncertainty number can be calculated is：

It is hereby achieved that contact weld corresponding weight for 5.74. using same method can obtain mechanism's clamping stagnation, Rotating mechanical failure, the pin corresponding weight that comes off is：3.78th, 7.87,2.02. normalize ω=[0.2971,0.1956, 0.4073,0.1045]

Use formula can be calculated primary cut-out refuse point probability of malfunction for：

P=0.24 × 0.2971+0.26 × 0.1956+0.33 × 0.4073+0.17 × 0.1045

=0.2743

The present invention is described in detail above, specific case used herein is to principle of the invention and embodiment party Formula is set forth, and the explanation of above example is only intended to help and understands the method for the present invention and its core concept；Meanwhile, it is right In those of ordinary skill in the art, according to thought of the invention, change is had in specific embodiments and applications Part, in sum, this specification content should not be construed as limiting the invention.

Claims (1)

1. a kind of primary cut-out refuses the determination method of point probability of malfunction, it is characterised in that preferred, comprises the following steps：

S100：Acquisition causes primary cut-out to refuse the Probability p that each failure factor of point failure occurs₁, p₂, p₃..., p_n；

S200：The weight of each failure factor is calculated using the method for Uncertainty number；

Be provided with m expert carries out Assessment of Important to n index for triggering breaker to refuse point failure, and m is obtained specially by evaluating Family obtains the importance Uncertainty number of index j on the n estimate of index：

In formula, A represents Uncertainty number, [x₁, x_k] it is index importance interval,For index importance value is credible Density of Degree Distribution function, α_iImportance value corresponding to index j is x_iNormalization reliability and, k for failure number of types Mesh, x_iIt is a certain value of index weight；

Calculate the mathematical expectation E (A of the Uncertainty number_j), formula is as follows：

E (A) is single order Uncertainty number, wherein α=α_i+α₂+…+α_k,The as weighted value of index j；

S300：Calculate the normalized weight of each failure factor；

${\mathrm{\ω}}_i=\frac{x_i}{x_1+x_2+\·\·\·+x_n},i=1,2,\·\·\·n$

S400：The probability and weight occurred according to each failure factor, calculate primary cut-out and refuse a point probability of malfunction；

P=p₁×ω₁+p₂×ω₂+…+p_n×ω_n。