CN105974303A - Reliability evaluation test method of built-in load switch for electric energy meter - Google Patents

Abstract

The invention discloses a reliability evaluation test method of a built-in load switch for an electric energy meter. The reliability evaluation test method is characterized by including a load switch mechanical reliability and electrical reliability evaluation method. According to the method, a failure rate is adopted as a reliability characteristic parameter, and grading testing is carried out through adopting a fixed event censoring mode. The method includes the following steps that: S01, an allowable failure number Ac and a censoring failure number rc are selected, wherein rc and Ac satisfies a relational expression that rc=Ac+1; S02, the number Tc of times of censoring is obtained according to the allowable failure number Ac and a pre-selected failure rate grade; S03, the number tz of times of test censoring of test pieces is selected; S04, the number n of the test pieces is determined according to Tc, Ac and tz; S05, n test pieces are randomly sampled from products in batch production; S06, test and inspection are carried out according to regulations; S07, a failure number r and the number of times of the test of failed products are calculated; and S08, a test result is judged. The test method of the invention has the advantages of simple operation, accurate detection and the like.

Description

Electric energy meter is by built-in on-load switch reliability assessment test method

Technical field

The invention mainly relates to electrical equipment technical field, refer in particular to a kind of built-in on-load switch reliability assessment of electric energy meter Test method.

Background technology

The electric energy meter quality of built-in on-load switch is directly connected to customer service quality and safe operation of electric network.Entirely Since state carries out low-voltage collecting meter reading construction on a large scale, Guo Wang company telephone traffic is huge, and the metering fault accepted reports for repairment in business, electric energy Table is in higher proportion by built-in on-load switch fault, account for that whole metering fault reports for repairment 60%.According to statistics, Hunan Province in 2014 Utilities Electric Co. accepts metering device troublshooting 28000, wherein reaches 16800 because of reporting for repairment of causing of built-in on-load switch fault Rising, the quality problems of built-in on-load switch bring huge economic loss and bad social influence to grid company.Cause This, promote the reliability of built-in on-load switch, inherently promotes the quality of built-in on-load switch, reduces because of built-in on-load switch The fault lost efficacy and cause, for promoting good service level, it is ensured that the stabilization of power grids, saves business manpower, material resources, financial resources, tool There are great social meaning and economic implications.

By analyze, electric energy meter is relatively low with built-in on-load switch operation frequency, but higher to reliability requirement, typically with Family arrearage or short circuit etc. the most just can operate separating brake, and after subscriber payment completes or when recovering normal, operation is closed a floodgate.With Time, when demand charge is abundant and state is normal, action do not answered by built-in on-load switch, it is ensured that user's normal electricity consumption；When circuit is sent out When raw overload or short trouble, should action in time, open failure electric current, with protection circuit and electrical equipment.

Summary of the invention

The technical problem to be solved in the present invention is that the technical problem existed for prior art, and the present invention provides one Kind principle is simple, easy and simple to handle and detects the built-in on-load switch reliability assessment test method of electric energy meter accurately.

For solving above-mentioned technical problem, the technical scheme that the present invention proposes is:

A kind of electric energy meter is by built-in on-load switch reliability assessment test method, including on-load switch Mechanical Reliability and electricity Gas reliability estimation method, all as characteristic quantities and uses Based on Censored Data mode to carry out deciding grade and level test, step using crash rate Suddenly it is:

S01, selected permission failure number A_cWith truncation failure number r_c, wherein r_c=A_c+1；

S02, according to allow failure number A_cWith the failure rate level of preliminary election, determine from machinery set in advance and electrical reliability Level test table obtains truncation number of times T_c；

S03, the test cut-off number of times t of selected test product_z, t_zShould be less than the electrical endurance specified in product standard and machinery Life-span number of times；

S04, according to T_c、A_cAnd t_z, formula (15) determine test product number n, wherein

N=T_c/t_z+A_c(15)；

S05, randomly drawing n test product from the product of batch production, wherein the product quantity for sampling is no less than trying 10 times of product number n；

S06, be carried out in accordance with regulations test with detection；

S07, statistics failure number r and the test number (TN) of each inefficacy test product, the test number (TN) of each inefficacy test product presses off-test Time number of times calculate, and statistics accumulation test number (TN)；

S08, result of the test judge: when failure number r is not up to truncation failure number r_c, i.e. r≤A_c, and accumulation test number (TN) reaches To or exceeded truncation number of times T_c, then pass the test it is judged to；When accumulation test number (TN) is not up to truncation number of times, and relevant failure number R has met or exceeded truncation failure number r_c, i.e. r > A_c, then it is judged to test defective.

Preferably, after deciding grade and level pass the test, carrying out the maintenance test of this failure rate level, step is as follows:

S21, selected permission failure number A_c, according to failure rate level and the selected permission failure number of product pass the test A_c, from test table defined the level by machinery set in advance and electrical reliability, obtain truncation number of times；

S22, the test cut-off number of times of selected test product, determine test product number n；

S23, extraction test product, be carried out in accordance with regulations test and detection；

S24, statistics failure number r and the test number (TN) of each inefficacy test product, statistics accumulation test number (TN)；

S25, result of the test judge: if maintaining pass the test, then should continue to tie up by the maintenance cycle of regulation next time Hold test；If maintaining test defective, then should redefine its failure rate level；When redefining failure rate level, by this product Product total Test data from test of defining the level first add up, and the failure rate level of product should be according to accumulative relevant failure Number redefines.

Preferably, after deciding grade and level pass the test, the upgrade test of this failure rate level, the wherein data of upgrade test are carried out From deciding grade and level test and maintain test test product carry out extend test and for upgrade test put into test product test draw, upgrading try The step tested is as follows:

S31, selected product failure rate grade to be upgraded, this failure rate level is than the failure level determined in deciding grade and level test High one-level；

S32, selected permission failure number A_c；

S33, according to selected failure rate level and allow failure number, upgrade from machinery set in advance and electrical reliability Test table is found truncation number of times T_c；

S34, according to T_cDetermine and extend the number of times tested and the test product number put into for upgrade test and test number (TN)；

S35, extraction test product, be carried out in accordance with regulations test and detection；

S36, statistics failure number r and the test number (TN) of each inefficacy test product, statistics accumulation test number (TN) T；

S37, result of the test judge: if upgrade test is qualified, then should carry out the maintenance of this grade by the maintenance cycle of regulation Test；If upgrade test is defective, then should redefine its failure rate level；When redefining failure rate level, by this product Total Test data add up, the failure rate level of product is the most true according to the test number (TN) of accumulative failure number and accumulation Fixed.

Preferably, in step S02, the generation process of described machinery and electrical reliability deciding grade and level test table is as follows:

S41, according to the crash rate operational characteristic curve in reliability sampling theory, and the on-load switch life-span obeys and singly refers to The characteristic of number distribution, can obtain

$L\left(\mathrm{\λ}\right)=\underset{r=0}{\overset{A_c}{\mathrm{\Σ}}}{C}_n^r{(1-e^{-\mathrm{\λ}t})}^r{\left(e^{-\mathrm{\λ}t}\right)}^{n-r}---\left(3\right)$

Wherein 1-L (λ₀)=α (1)

L(λ₁)=β (2)

λ₀Receivable crash rate；α producer risk rate；λ₁The most receivable crash rate；β user risk Rate；

S42, set n extracted sampling test to inefficacy r during stipulated number t, due to built-in on-load switch crash rate Relatively low, meet n λ t < 5 and λ t < 0.1, binomial distribution can be approximately Poisson distribution, i.e.

$L\left(\mathrm{\&lambda;}\right)\&ap;\underset{r=0}{\overset{A_c}{\mathrm{\&Sigma;}}}\frac{e^{-n\mathrm{\&lambda;}t}{\left(n\mathrm{\&lambda;}t\right)}^r}{r!}---\left(4\right)$

T=nt (5)

Formula (5) is substituted into formula (4) can obtain:

$L\left(\mathrm{\&lambda;}\right)\&ap;\underset{r=0}{\overset{A_c}{\mathrm{\&Sigma;}}}\frac{e^{-nT}{\left(nT\right)}^r}{r!}---\left(6\right)$

Formula (6) substitution (2) can be obtained:

$L\left({\mathrm{\&lambda;}}_1\right)\&ap;\underset{r=0}{\overset{A_c}{\mathrm{\&Sigma;}}}\frac{e^{-nT}{\left(nT\right)}^r}{r!}=\mathrm{\&beta;}---\left(7\right)$

If f is (x, 2A_c+ 2) it is that degree of freedom is equal to 2A_cThe χ of+2²The density function of distribution, then

$\mathrm{\&beta;}\&ap;\underset{r=0}{\overset{A_c}{\mathrm{\&Sigma;}}}\frac{e^{-nT}{\left(nT\right)}^r}{r!}={\&Integral;}_{2{\mathrm{\&lambda;}}_{1}T}^{\mathrm{\&infin;}}f(x,2A_c+2)dx---\left(8\right)$

Obviously, 2 λ₁T is 2A equal to degree of freedom_cThe χ of+2²Quantile on the downside of distribution 1-βI.e.

$2{\mathrm{\&lambda;}}_{1}T={\mathrm{\&chi;}}_{1-\mathrm{\&beta;}}^2(2A_c+2)---\left(9\right)$

Or it is

S43, the sampling scheme of employing crash rate checking, by the λ in formula (11)₁By maximum failure rate λ_maxReplace, confidence level 1-β takes 0.9, calculates truncation number of times T_c, according to test statistics result, to different A_cValue tries to achieve the T of correspondence_c, thus obtain machine Tool and electrical reliability deciding grade and level test table.

Preferably, also include on-load switch short circuits appraisal procedure, as characteristic quantities and adopt using success rate Carrying out deciding grade and level test by Based on Censored Data mode, step is:

S51, according to allow failure number A_cWith the ranked success ratio of preliminary election, short circuits set in advance deciding grade and level test Looking into test product number n in table, n typically cannot be less than 10；

S52, from batch production product randomly draw n test product, for sample product quantity be no less than test product number n 10 times；

S53, be carried out in accordance with regulations test with detection, add up failure number r；

S54, result of the test judge: when failure number r has met or exceeded cut-off failure number r_c, i.e. r > A_c, then it is judged to test not Qualified.

Preferably, after deciding grade and level pass the test, carrying out the maintenance test of this failure rate level, step is as follows:

S61, selected permission failure number A_cAnd ranked success ratio, short circuits set in advance maintain test table to look into examination Product number n；

S62, extraction test product, be carried out in accordance with regulations test and detection, add up failure number r；

S63, result of the test judge: if maintaining pass the test, then should continue to tie up by the maintenance cycle of regulation next time Hold test；If maintaining test defective, then should redefine its ranked success ratio；When redefining ranked success ratio, by deciding grade and level Experiment performs.

Preferably, the product of deciding grade and level pass the test proceeds upgrade test, and the data of upgrade test can be from deciding grade and level test Carrying out extending test with the test product maintaining test and the test product test for upgrade test input draws, step is as follows:

S71, selected permission success rate and product ranked success ratio to be upgraded, this ranked success ratio is higher than original grade One-level；

S72, according to selected ranked success ratio and allow successfully to count, by short circuits upgrade test table set in advance Finding test product number, wherein short circuits upgrade test table is identical with short circuits deciding grade and level test table；

S73, extraction test product, be carried out in accordance with regulations test and detection, add up success rate；

S74, result of the test judge: if upgrade test is qualified, then should carry out the maintenance of this grade by the maintenance cycle of regulation Test；If upgrade test is defective, then should redefine its ranked success ratio；When redefining ranked success ratio, directly by fixed Level experiment performs.

Preferably, in step s 51, the generation process of described short circuits deciding grade and level test table is:

Success rate operational characteristic curve in S81, foundation reliability sampling theory, can obtain:

1-L(R₀)=α (11)

L(R₁)=β (12)

And success rate discrimination ratio

$D_r=\frac{1-R_1}{1-R_0}---\left(13\right);$

S82, based on binomial distribution, built-in on-load switch short circuits test sampling verification scheme can be by formula (14) represent:

$\underset{k=0}{\overset{A_c}{\mathrm{\&Sigma;}}}{C}_n^r{R}_0^{n-k}{(1-R_0)}^k=1-\mathrm{\&alpha;}$

$\underset{k=0}{\overset{A_c}{\mathrm{\&Sigma;}}}{C}_n^r{R}_1^{n-k}{(1-R_1)}^k=\mathrm{\&beta;}---\left(14\right)$

S83, according to test statistics result, in the deciding grade and level test and upgrade test of short circuits, α, β take 0.2, success Rate discrimination ratio D_rTake 3, A_cTake 3, then can calculate the test product number of corresponding different success rate, thus obtain short circuits deciding grade and level examination Test table.

Compared with prior art, it is an advantage of the current invention that:

The electric energy meter of the present invention is by built-in on-load switch reliability assessment test method, and tool is in following several big features:

(1) by analyzing the electric energy meter work characteristics of built-in on-load switch, it is proposed that employing crash rate can as machinery By property and the performance assessment criteria of electrical reliability, use success rate as the performance assessment criteria of short circuits.

(2) to the detection limit in the experimental condition of Mechanical Reliability, electrical reliability and short circuits, process of the test and Detection limit and detection method, test criterion after detection method, test have made clear and definite regulation, it is ensured that result of the test accurate Property.

(3) set up and study the mathematical model of crash rate and success rate, propose machinery and electrical reliability deciding grade and level test and Upgrade test scheme, machinery and electrical reliability maintain the deciding grade and level of testing program, short circuits and upgrade test scheme, short circuit can Testing program is maintained by property.

(4) the deciding grade and level test of electric energy meter built-in on-load switch three class reliability, upgrade test, the examination of maintenance test are proposed Test program, it is ensured that the operability of test method.

Accompanying drawing explanation

Fig. 1 is the crash rate operating characteristic curve figure of the present invention.

Fig. 2 is 2 λ of the present invention₁Graph of relation between T and β.

Fig. 3 is the success rate operating characteristic curve figure of the present invention.

Detailed description of the invention

Below in conjunction with Figure of description and specific embodiment, the invention will be further described.

As shown in Figure 1 to Figure 3, the electric energy meter of the present embodiment by built-in on-load switch reliability assessment test method, including The assessment of on-load switch Mechanical Reliability, electrical reliability assessment and short circuits assessment, wherein electric energy meter is opened with built-in load The Mechanical Reliability closed and electrical reliability use crash rate as its characteristic quantities, and short circuits uses success rate to make For its characteristic quantities.Reliability index and reliability test method to test illustrate below:

1, reliability index:

By the numerical value of its maximum failure rate (success rate) be divided into six grades (three grades, level Four, sub-Pyatyi, Pyatyi, six grades, Seven grades).The title of grade and maximum failure rate (minimum success rate) are shown in Table 1:

Table 1: grade name and maximum failure rate (minimum success rate)

Tab.1Grade name and maximum failure rate(minimum success rate)

2, reliability test method

The experimental condition of 2.1 every reliability assessments is respectively as follows:

2.1.1 Mechanical Reliability experimental condition

When carrying out Mechanical Reliability test, test product should use control circuit rated voltage, and pulsewidth uses 120ms, built-in negative Lotus switch contact loop adds 24VDC voltage 100mA current monitor signal, and during test, test product cycle-index hourly should be less than Setting in product standard, operating frequency preferably chooses 30 times/min, and closure state time and off-state time are than for 1:1.

2.1.2 electrical reliability experimental condition

When carrying out electrical reliability test, test product should use control circuit rated voltage, and pulsewidth uses 120ms, built-in negative Lotus switch passes to rated voltage, and rated operational current, and 10s connects, and 20s disconnects.Test sequence sees table 2.

Table 2: electrical reliability test sequence

Tab.2Electric reliability test sequence

2.1.3 short circuits experimental condition

The test of short circuits sets experimental condition according to the requirement of IEC62053-21 and IEC 62055-31 standard, The built-in on-load switch experimental condition of different rated operational currents is shown in Table 3.According to IEC 62055-31 standard, built-in load is opened Closing and be categorized as UC1, UC2, UC3, UC4 by use, In is rated current.

Table 3: different rated current built-in on-load switch experimental conditions

Tab.3Different rated current latching relay test conditions

Short circuit current tolerance 1 test: test preload switch should action 3 under the conditions of rated voltage and rated operational current Secondary, each 5s Guan Bi, 5s disconnect；Then being installed by the regulation of mounting condition by test product, on-load switch is in closure state, presses " shorted load condition " of table 3 regulation is carried out continuously 3 tolerances, every time time interval 1min of tolerance.

Short circuit current tolerance 2 test: test preload switch should action 3 under the conditions of rated voltage and rated operational current Secondary, each 5s Guan Bi, 5s disconnect；Then being installed by the regulation of mounting condition by test product, on-load switch is in closure state, presses " shorted load condition " of table 3 regulation carries out 3 short-circuit resistance test, cools down 1min every time, use specified driving voltage after test Test product carries out closed and disconnected operation test, and twice short circuit resistance test interval was less than 5 minutes.

Fault turn-on current is tested: test preload switch should action 3 under the conditions of rated voltage and rated operational current Secondary, each 5s Guan Bi, 5s disconnect；Then being installed by the regulation of mounting condition by test product, on-load switch is off, and presses " shorted load condition " of table 3 regulation carries out 3 call through tests, and the phase angle of current turns ON should be random, each call through test After rear cooling 1min, with specified driving voltage, test product being carried out closed and disconnected operation test, twice short circuit resistance test is spaced Less than 5 minutes.

Tolerance 1 and the sampling test products of the tolerance 2 each use 1/3n of test, and according to round when there is decimal, its Remaining sample carries out the test of project fault turn-on current.

2.2 test products prepare

First being test product extraction, test product should be from producing in batches under stable process conditions and through the qualified product detected Product are randomly drawed, and the product quantity for sampling is no less than 10 times of test product number n.

Then screening sample from test product, unless product standard states otherwise, screening uses under room temperature (15 DEG C～35 DEG C) Carrying out, screening conditions are outward appearance, closed procedure voltage, opening operation voltage, turn-off time, closing time, dielectric withstanding voltage, insulation The routine test project such as resistance, contact resistance.If test product has defective under screening conditions, defective test product should be rejected, And supply sample by regulation.The test product weeded out is not counted in relevant failure number r.

2.3 test product detections

2.3.1 process of the test detects

(1) mechanically and electrically detect during reliability test.Unless product standard states otherwise, owning of reply test product With in 40% time of "off" phase in 40% time of contact " on " phase within each action cycle, detection closes contact Contact drop and break contact between voltage.Process of the test does not allow test product is cleared up and adjusts.

(2) short circuits process of the test detects.Short circuit current tolerance 1 test does not detects in process of the test；Short circuit Electric current tolerance 2 test and fault current call through test detect the function of built-in on-load switch in process of the test.

2.3.2 detect after Shi Yan

(1) mechanically and electrically detect after reliability test.Unless product standard states otherwise, after test, tackle all mistake The effect outward appearance of test product, closed procedure voltage, opening operation voltage, closing time, turn-off time, contact resistance, dielectric properties, absolutely The projects such as edge resistance are tested.

(2) detect after short circuits test.Unless product standard states otherwise, short circuit tolerance electric current 2 is tested and fault The following items tackling all test products that do not lost efficacy after turn-on current test is tested:

When a) applying specified excitation first, the action situation of built-in on-load switch；

B) dielectric properties, contact resistance, surge voltage.

2.4 failure criteria

2.4.1 Mechanical Reliability failure criteria:

When any one situation following occurs, i.e. think that this test product lost efficacy:

(1), during built-in on-load switch Guan Bi, the ultimate value of contact drop is more than the 5% of contact circuit open-circuit voltage；

(2), when built-in on-load switch disconnects, the voltage between break contact is less than the 90% of contact circuit open-circuit voltage；

(3) built-in on-load switch is failure to actuate；

(4) test product parts have destructive damage, connection wire and parts to loosen；

(5) after test, contact resistance is more than the 150% of nominal value；

(6), in test product detection after experiment, in addition to contact resistance, other any one purpose testing results do not meet product The regulation of standard.

2.4.2 electrical reliability failure criteria

When any one situation following occurs, i.e. think that this test product lost efficacy:

(1) test product occurred in process of the test can not normal break-make；

(2) test product parts have destructive damage, connect wire and loose-parts；

(3) after test, contact resistance is more than the 150% of nominal value；

(4) after test, insulation resistance is less than the 10% of nominal value；

(5) dielectric properties after test, between contact, dielectric is pressure less than the 75% of nominal withstand voltage；

(6) test product after experiment detection in, in addition to above-mentioned project, other any one purpose testing result does not meets product The regulation of product standard.

2.4.3 short circuits failure criteria

When any one situation following occurs, i.e. think that this test product lost efficacy:

(1) short circuit current resistance test 1 is exploded, and outward appearance has damage；

(2) contact resistance is more than the 150% of nominal value；

(3) dielectric properties, between contact, dielectric is pressure less than the 75% of nominal withstand voltage；

(4) surge voltage does not meets product standard requirement.

3, before carrying out test procedure, reliability test sampling scheme is determined.

3.1 sampling scheme

Unless product standard states otherwise, the reliability compliance test of built-in on-load switch is recommended to use Based on Censored Data examination Test.Using crash rate checking sampling scheme for Mechanical Reliability and electrical reliability, short circuits uses success rate checking Sampling scheme.

3.1.1 crash rate checking sampling scheme

Theoretical according to reliability sampling, crash rate operational characteristic curve is as it is shown in figure 1, represent crash rate probability L (λ) and lose Relation between efficiency λ.

Understand according to Fig. 1, as built-in on-load switch crash rate λ < λ₀Time, then this pass the test of this batch of product；As λ=λ₀ Time, the probability that erroneous judgement does not receives is α；Work as λ > λ₁Time, then this test of this batch of product is judged to defective；As λ=λ₁Time, produce It is β that product are mistaken for probability that is qualified and that receive.

1-L(λ₀)=α (1)

L(λ₁)=β (2)

The built-in on-load switch life-span obeys single index distribution, and the available binomial probability formula (3) of L (λ) calculates

$L\left(\mathrm{\&lambda;}\right)=\underset{r=0}{\overset{A_c}{\mathrm{\&Sigma;}}}{C}_n^r{(1-e^{-\mathrm{\&lambda;}t})}^r{\left(e^{-\mathrm{\&lambda;}t}\right)}^{n-r}---\left(3\right)$

When determining the crash rate sampling scheme of built-in on-load switch, according to given λ₁, β value, take inefficacy truncation number A_c= 0,1,2..., obtain sampling number n, thus obtain the sampling scheme of crash rate test.

In crash rate proof scheme, by total number of operations T of test product and permission failure number A_cBetween relation come really The reliability level of fixed built-in on-load switch.If n the sampling test extracted is to inefficacy r during stipulated number t, due to built-in On-load switch crash rate is relatively low, meets n λ t < 5 and λ t < 0.1, and binomial distribution can be approximately Poisson distribution, i.e.

$L\left(\mathrm{\&lambda;}\right)\&ap;\underset{r=0}{\overset{A_c}{\mathrm{\&Sigma;}}}\frac{e^{-n\mathrm{\&lambda;}t}{\left(n\mathrm{\&lambda;}t\right)}^r}{r!}---\left(4\right)$

T=nt (5)

Formula (5) is substituted into formula (4) can obtain:

$L\left(\mathrm{\&lambda;}\right)\&ap;\underset{r=0}{\overset{A_c}{\mathrm{\&Sigma;}}}\frac{e^{-nT}{\left(nT\right)}^r}{r!}---\left(6\right)$

Formula (6) substitution (2) can be obtained:

$L\left({\mathrm{\&lambda;}}_1\right)\&ap;\underset{r=0}{\overset{A_c}{\mathrm{\&Sigma;}}}\frac{e^{-nT}{\left(nT\right)}^r}{r!}=\mathrm{\&beta;}---\left(7\right)$

If f is (x, 2A_c+ 2) it is that degree of freedom is equal to 2A_cThe χ of+2²The density function of distribution, then

$\mathrm{\&beta;}\&ap;\underset{r=0}{\overset{A_c}{\mathrm{\&Sigma;}}}\frac{e^{-nT}{\left(nT\right)}^r}{r!}={\&Integral;}_{2{\mathrm{\&lambda;}}_{1}T}^{\mathrm{\&infin;}}f(x,2A_c+2)dx---\left(8\right)$

Wherein 2 λ₁Relation between T and β is as shown in Figure 2.

Obviously, 2 λ₁It is 2A that T is equal to degree of freedom_cThe χ of+2²Quantile on the downside of distribution 1-βI.e.

$2{\mathrm{\&lambda;}}_{1}T={\mathrm{\&chi;}}_{1-\mathrm{\&beta;}}^2(2A_c+2)---\left(9\right)$

Or

For deciding grade and level test and the upgrade test of Mechanical Reliability and electrical reliability, use the sampling side of crash rate checking Case, by the λ in formula (10)₁By maximum failure rate λ in table 1_maxReplacing, confidence level 1-β takes 0.9, then can calculate in table 4 Truncation number of times T_c, according to test statistics result, to different A_cValue can try to achieve the T of correspondence_c, thus it is (the most mechanical and electric to obtain table 4 The deciding grade and level test of gas reliability and upgrade test).When maintaining test, confidence level 1-β takes 0.6, calculates table 5 (the most mechanical and electric Gas reliability maintains test table).

Table 4: machinery and electrical reliability deciding grade and level test and upgrade test scheme

Tab.4Mechanical and electrical reliability grading test and upgrade test scheme

Table 5: machinery and electrical reliability maintain testing program

Tab.5Mechanical and electrical reliability maintain test scheme

4.1.2 success rate checking sampling scheme

Owing to short circuit is occurrent event for unique user, therefore verify as built-in load using success rate The sampling scheme of switch short test.The probability L that success rate receives_RAnd the relation between success rate R is as shown in Figure 3.

Understand according to Fig. 3, when built-in on-load switch success rate R R₀Time, then this pass the test of this batch products；Work as R= R₀Time, the probability that erroneous judgement does not receives is α；As R < R₁Time, then this test of this batch products is judged to defective；Work as R=R₁ Time, it is β that product is mistaken for probability that is qualified and that receive.

1-L(R₀)=α (11)

L(R₁)=β (12)

Success rate discrimination ratio

$D_r=\frac{1-R_1}{1-R_0}---\left(13\right)$

Based on binomial distribution, the sampling verification scheme of built-in on-load switch short circuits test can be by formula (14) Represent.

$\begin{array}{c}\underset{k=0}{\overset{A_c}{\mathrm{\&Sigma;}}}{C}_n^r{R}_0^{n-k}{(1-R_0)}^k=1-\mathrm{\&alpha;}\\ \underset{k=0}{\overset{A_c}{\mathrm{\&Sigma;}}}{C}_n^r{R}_1^{n-k}{(1-R_1)}^k=\mathrm{\&beta;}\end{array}---\left(14\right)$

According to test statistics result, in the deciding grade and level test and upgrade test of short circuits, α, β take 0.2, and success rate is reflected Not than D_rTake 3, A_cTaking 3, then can calculate the test product number of corresponding different success rate, concrete (i.e. short circuits is fixed as shown in table 6 Level and upgrade test table).When maintaining test, α, β take 0.3, success rate discrimination ratio D_rTake 3, A_cTake 2, calculate table 7 (the shortest Road reliability maintains test table).

Table 6: short circuits deciding grade and level and upgrade test scheme

Tab.6Short circuit reliability grading and upgrade test scheme

Table 7: short circuits maintains testing program

Tab.7Short circuit reliability maintain test scheme

5, after reliability test sampling scheme determines, corresponding test procedure is entered.

The assessment of the most every on-load switch Mechanical Reliability, electrical reliability assessment and the test journey of short circuits assessment Sequence all includes deciding grade and level test, maintains test and upgrade test, particularly as follows:

5.1 mechanically and electrically reliability test programs

5.1.1 define the level test

(1) selected permission failure number A_cWith truncation failure number r_c(r_c=A_c+ 1), it is recommended that in the range of 2～5, select A_c；

(2) according to selected failure rate level and A_c, table 4 find truncation number of times T_c；

(3) the test cut-off number of times t of selected test product_z, t_zShould be less than the electric life specified in product standard and mechanical life Number of times, it is recommended that electrical reliability is preferably t_z=104 times, Mechanical Reliability is preferably t_z=105 times；

(4) according to T_c、A_cAnd t_z, formula (15) determine that test product number n, n typically cannot be less than 10.

N=T_c/t_z+A_c (15)

(5) randomly drawing n test product from the product of batch production, the product quantity for sampling is no less than test product number n 10 times；

(6) test and detection it are carried out in accordance with regulations；

(7) statistical correlation failure number r and the correlation test number of times of each inefficacy test product, to the relevant failure detected after test Test product, its correlation test number of times is calculated by number of times during off-test, statistics accumulation correlation test number of times；

(8) result of the test judges.When relevant failure number r is not up to truncation failure number r_c(i.e. r≤A_c), and accumulate relevant examination Test number of times and met or exceeded truncation number of times, be then judged to pass the test, when accumulation correlation test number of times is not up to truncation number of times, and Relevant failure number r has met or exceeded truncation failure number r_c(i.e. r > A_c), then it is judged to test defective.

5.1.2 test is maintained

The product of deciding grade and level pass the test, unless product standard states otherwise, should carry out this by the maintenance week number of regulation in table 5 The maintenance test of grade, maintains test to carry out by follow procedure:

(1) selected permission failure number A_c, according to failure rate level and the selected permission failure number of product pass the test, Truncation number of times is found by table 5；

(2) the test cut-off number of times of selected test product, determines test product number n；

(3) extraction test product, is carried out in accordance with regulations test and detection；

(4) statistical correlation failure number r and the correlation test number of times of each inefficacy test product, statistics accumulation correlation test number of times；

(5) result of the test judges.If maintenance pass the test, then should continue to maintain by the maintenance cycle of regulation next time Test；If maintaining test defective, then should redefine its failure rate level；When redefining failure rate level, should be by this product Product total Test data (include maintaining and test underproof data) from test of defining the level first add up, the inefficacy of product Rate grade should be determined by table 1 according to accumulative relevant failure number.

5.1.3 upgrade test

The product of deciding grade and level pass the test can proceed with upgrade test.The data of upgrade test can be from deciding grade and level test and maintenance The test product of test carries out extending test and the test product test for upgrade test input draws.Upgrade test is entered by follow procedure OK.

(1) selected product failure rate grade (typically than the original high one-level of grade) to be upgraded；

(2) selected permission failure number A_c；

(3) according to selected failure rate level and permission failure number, table 4 truncation number of times T is found_c；

(4) according to T_cDetermine and extend the number of times tested and the test product number put into for upgrade test and test number (TN)；

(5) extraction test product, is carried out in accordance with regulations test and detection；

(6) statistical correlation failure number r and the correlation test number of times of each inefficacy test product, statistics accumulation correlation test number of times T；

(7) result of the test judges.If upgrade test is qualified, then should by regulation the maintenance cycle carry out this grade maintenance examination Test；If upgrade test is defective, then should redefine its failure rate level；When redefining failure rate level, should be by this product Total Test data add up, the failure rate level of product should be according to accumulative relevant failure number and the correlation test of accumulation Number of times is determined by table 1.

5.2 short circuits test procedures

5.2.1 define the level test

Deciding grade and level test is carried out by follow procedure:

(1) according to selected ranked success ratio and A_c, table 6 looking into test product number n, n typically cannot be less than 10；

(2) randomly drawing n test product from the product of batch production, the product quantity for sampling is no less than test product number n 10 times；

(3) test and detection, statistical correlation failure number r it are carried out in accordance with regulations；

(4) result of the test judges.When relevant failure number r has met or exceeded cut-off failure number r_c(i.e. r > A_c), then it is judged to examination Test defective.

5.2.2 test is maintained

The product of deciding grade and level pass the test, unless product standard states otherwise, should carry out this by the maintenance week number of regulation in table 7 The maintenance test of grade, maintains test to carry out by follow procedure:

(1) power grade and A it are selected to_c, table 7 look into test product number n；

(2) extraction test product, is carried out in accordance with regulations test and detection, statistical correlation failure number r；

(3) result of the test judges.If maintenance pass the test, then should continue to maintain by the maintenance cycle of regulation next time Test；If maintaining test defective, then should redefine its ranked success ratio；When redefining ranked success ratio, real by deciding grade and level Test execution.

5.2.3 upgrade test

The product of deciding grade and level pass the test can proceed with upgrade test.The data of upgrade test can be from deciding grade and level test and maintenance The test product of test carries out extending test and the test product test for upgrade test input draws.Upgrade test is entered by follow procedure OK.

(1) selected product ranked success ratio (typically than the original high one-level of grade) to be upgraded, selected permission success rate；

(2) according to selected ranked success ratio and permission failure number, table 6 test product number is found；

(3) extraction test product, is carried out in accordance with regulations test and detection, statistical correlation failure number r；

(4) result of the test judges.If upgrade test is qualified, then should by regulation the maintenance cycle carry out this grade maintenance examination Test；If upgrade test is defective, then should redefine its ranked success ratio；When redefining ranked success ratio, directly by deciding grade and level Experiment performs.

Below being only the preferred embodiment of the present invention, protection scope of the present invention is not limited merely to above-described embodiment, All technical schemes belonged under thinking of the present invention belong to protection scope of the present invention.It should be pointed out that, for the art For those of ordinary skill, some improvements and modifications without departing from the principles of the present invention, should be regarded as the protection of the present invention Scope.

Claims (8)

1. an electric energy meter is by built-in on-load switch reliability assessment test method, it is characterised in that include on-load switch machinery Reliability and electrical reliability appraisal procedure, all as characteristic quantities and use Based on Censored Data mode to carry out determining using crash rate Level test, step is:

S01, selected permission failure number A_cWith truncation failure number r_c, wherein r_c=A_c+1；

S02, according to allow failure number A_cWith the failure rate level of preliminary election, define the level from machinery set in advance and electrical reliability and try Test and table obtains truncation number of times T_c；

S03, the test cut-off number of times t of selected test product_z, t_zShould be less than the electrical endurance specified in product standard and mechanical life Number of times；

S04, according to T_c、A_cAnd t_z, formula (15) determine test product number n, wherein

N=T_c/t_z+A_c(15)；

S05, randomly drawing n test product from the product of batch production, wherein the product quantity for sampling is no less than test product number n 10 times；

S06, be carried out in accordance with regulations test with detection；

S07, statistics failure number r and the test number (TN) of each inefficacy test product, the test number (TN) of each inefficacy test product is by during off-test Number of times calculates, and statistics accumulation test number (TN)；

S08, result of the test judge: when failure number r is not up to truncation failure number r_c, i.e. r≤A_c, and accumulation test number (TN) reaches or Exceed truncation number of times T_c, then pass the test it is judged to；When accumulation test number (TN) is not up to truncation number of times, and relevant failure number r reaches To or exceeded truncation failure number r_c, i.e. r > A_c, then it is judged to test defective.

Electric energy meter the most according to claim 1 is by built-in on-load switch reliability assessment test method, it is characterised in that After deciding grade and level pass the test, carrying out the maintenance test of this failure rate level, step is as follows:

S21, selected permission failure number A_c, according to failure rate level and the selected permission failure number A of product pass the test_c, from Machinery set in advance and electrical reliability deciding grade and level test table obtain truncation number of times；

S22, the test cut-off number of times of selected test product, determine test product number n；

S23, extraction test product, be carried out in accordance with regulations test and detection；

S24, statistics failure number r and the test number (TN) of each inefficacy test product, statistics accumulation test number (TN)；

S25, result of the test judge: if maintaining pass the test, then should continue to maintain examination by the maintenance cycle of regulation next time Test；If maintaining test defective, then should redefine its failure rate level；When redefining failure rate level, by this product from The total Test data that deciding grade and level has been tested first add up, and the failure rate level of product should be according to accumulative relevant failure number weight Newly determined.

Electric energy meter the most according to claim 2 is by built-in on-load switch reliability assessment test method, it is characterised in that After deciding grade and level pass the test, carrying out the upgrade test of this failure rate level, wherein the data of upgrade test from deciding grade and level test and maintain The test product of test carries out extending test and the test product test for upgrade test input draws, the step of upgrade test is as follows:

S31, selected product failure rate grade to be upgraded, this failure rate level is higher by one than the failure level determined in deciding grade and level test Level；

S32, selected permission failure number A_c；

S33, according to selected failure rate level and allow failure number, from machinery set in advance and electrical reliability upgrade test Table is found truncation number of times T_c；

S34, according to T_cDetermine and extend the number of times tested and the test product number put into for upgrade test and test number (TN)；

S35, extraction test product, be carried out in accordance with regulations test and detection；

S36, statistics failure number r and the test number (TN) of each inefficacy test product, statistics accumulation test number (TN) T；

S37, result of the test judge: if upgrade test is qualified, then should by regulation the maintenance cycle carry out this grade maintenance test； If upgrade test is defective, then should redefine its failure rate level；When redefining failure rate level, whole by this product Test data adds up, and the failure rate level of product redefines according to the test number (TN) of accumulative failure number and accumulation.

Electric energy meter the most according to claim 1 is by built-in on-load switch reliability assessment test method, it is characterised in that In step S02, the generation process of described machinery and electrical reliability deciding grade and level test table is as follows:

S41, according to the crash rate operational characteristic curve in reliability sampling theory, and the on-load switch life-span obeys single index and divides The characteristic of cloth, can obtain

$L\left(\mathrm{\&lambda;}\right)=\underset{r=0}{\overset{A_c}{\&Sigma;}}{C}_n^r{(1-e^{-\mathrm{\&lambda;}t})}^r{\left(e^{-\mathrm{\&lambda;}t}\right)}^{n-r}---\left(3\right)$

Wherein 1-L (λ₀)=α (1)

L(λ₁)=β (2)

λ₀Receivable crash rate；α producer risk rate；λ₁The most receivable crash rate；β user relative risk；

S42, set n extracted sampling test to inefficacy r during stipulated number t, owing to built-in on-load switch crash rate is relatively low, Meeting n λ t < 5 and λ t < 0.1, binomial distribution can be approximately Poisson distribution, i.e.

$L\left(\mathrm{\&lambda;}\right)\&ap;\underset{r=0}{\overset{A_c}{\&Sigma;}}\frac{e^{-n\mathrm{\&lambda;}t}{\left(n\mathrm{\&lambda;}t\right)}^r}{r!}---\left(4\right)$

T=nt (5)

Formula (5) is substituted into formula (4) can obtain:

$L\left(\mathrm{\&lambda;}\right)\&ap;\underset{r=0}{\overset{A_c}{\&Sigma;}}\frac{e^{-nT}{\left(nT\right)}^r}{r!}---\left(6\right)$

Formula (6) substitution (2) can be obtained:

$L\left({\mathrm{\&lambda;}}_1\right)\&ap;\underset{r=0}{\overset{A_c}{\&Sigma;}}\frac{e^{-nT}{\left(nT\right)}^r}{r!}=\mathrm{\&beta;}---\left(7\right)$

If f is (x, 2A_c+ 2) it is that degree of freedom is equal to 2A_cThe χ of+2²The density function of distribution, then

$\mathrm{\&beta;}\&ap;\underset{r=0}{\overset{A_c}{\&Sigma;}}\frac{e^{-nT}{\left(nT\right)}^r}{r!}={\&Integral;}_{2{\mathrm{\&lambda;}}_{1}T}^{\mathrm{\&infin;}}f(x,2A_c+2)dx---\left(8\right)$

Obviously, 2 λ₁T is 2A equal to degree of freedom_cThe χ of+2²Quantile on the downside of distribution 1-βI.e.

$2{\mathrm{\&lambda;}}_{1}T={\mathrm{\&chi;}}_{1-\mathrm{\&beta;}}^2(2A_c+2)---\left(9\right)$

Or it is

S43, the sampling scheme of employing crash rate checking, by the λ in formula (11)₁By maximum failure rate λ_maxReplacing, confidence level 1-β takes 0.9, calculate truncation number of times T_c, according to test statistics result, to different A_cValue tries to achieve the T of correspondence_c, thus obtain machinery and Electrical reliability deciding grade and level test table.

Electric energy meter the most as claimed in any of claims 1 to 4 by built-in on-load switch reliability assessment test method, It is characterized in that, also include on-load switch short circuits appraisal procedure, fixed using success rate as characteristic quantities employing Number truncation mode carries out deciding grade and level test, and step is:

S51, according to allow failure number A_cWith the ranked success ratio of preliminary election, short circuits set in advance deciding grade and level test in table Looking into test product number n, n typically cannot be less than 10；

S52, from batch production product randomly draw n test product, for sample product quantity be no less than the 10 of test product number n Times；

S53, be carried out in accordance with regulations test with detection, add up failure number r；

S54, result of the test judge: when failure number r has met or exceeded cut-off failure number r_c, i.e. r > A_c, then it is judged to test and does not conforms to Lattice.

Electric energy meter the most according to claim 5 is by built-in on-load switch reliability assessment test method, it is characterised in that After deciding grade and level pass the test, carrying out the maintenance test of this failure rate level, step is as follows:

S61, selected permission failure number A_cAnd ranked success ratio, short circuits set in advance maintain test table to look into test product number n；

S62, extraction test product, be carried out in accordance with regulations test and detection, add up failure number r；

S63, result of the test judge: if maintaining pass the test, then should continue to maintain examination by the maintenance cycle of regulation next time Test；If maintaining test defective, then should redefine its ranked success ratio；When redefining ranked success ratio, by deciding grade and level experiment Perform.

Electric energy meter the most according to claim 6 is by built-in on-load switch reliability assessment test method, it is characterised in that fixed The product of level pass the test proceeds upgrade test, and the data of upgrade test can be entered from the test product of deciding grade and level test and maintenance test Row extends test and the test product test for upgrade test input draws, step is as follows:

S71, selected permission success rate and product ranked success ratio to be upgraded, this ranked success ratio is higher than original grade by one Level；

S72, according to selected ranked success ratio and allow successfully to count, short circuits upgrade test table set in advance find Test product number, wherein short circuits upgrade test table is identical with short circuits deciding grade and level test table；

S73, extraction test product, be carried out in accordance with regulations test and detection, add up success rate；

S74, result of the test judge: if upgrade test is qualified, then should by regulation the maintenance cycle carry out this grade maintenance test； If upgrade test is defective, then should redefine its ranked success ratio；When redefining ranked success ratio, directly by deciding grade and level experiment Perform.

8. according to the electric energy meter described in any one in claim 5 to 7 by built-in on-load switch reliability assessment test method, It is characterized in that, in step s 51, the generation process of described short circuits deciding grade and level test table is:

Success rate operational characteristic curve in S81, foundation reliability sampling theory, can obtain:

1-L(R₀)=α (11)

L(R₁)=β (12)

And success rate discrimination ratio

$D_r=\frac{1-R_1}{1-R_0}---\left(13\right);$

S82, based on binomial distribution, built-in on-load switch short circuits test sampling verification scheme can be by formula (14) Represent:

$\underset{k=0}{\overset{A_c}{\&Sigma;}}{C}_n^r{R}_0^{n-k}{(1-R_0)}^k=1-\mathrm{\&alpha;}$

$\underset{k=0}{\overset{A_c}{\&Sigma;}}{C}_n^r{R}_1^{n-k}{(1-R_1)}^k=\mathrm{\&beta;}---\left(14\right)$

S83, according to test statistics result, in the deciding grade and level test and upgrade test of short circuits, α, β take 0.2, and success rate is reflected Not than D_rTake 3, A_cTake 3, then can calculate the test product number of corresponding different success rate, thus obtain short circuits deciding grade and level test table.