CN104166785B - Indicator system for evaluating reliability of microcomputer relay protection device - Google Patents

Abstract

The invention relates to an indicator system for evaluating the reliability of a microcomputer relay protection device. The indicator system involves the following steps of firstly, calculating a reliability indicator R of the protection device; secondly, calculating a power swing indicator S of the protection device; thirdly, calculating the sensitivity indicator L of the protection device; fourthly, calculating a durability indicator N of the protection device; fifthly, calculating a maintenance indicator W of the protection device; sixthly, calculating an economy indicator J of the protection device; seventhly, converting the obtained reverse evaluation indicators into forward indicators by calculating the indicators R, S, L, N, W and J so that all the indicators can have the same directivity, converting all the forward indicators into relative value indicators, and finally comprehensively and uniformly evaluating the reliability of the relay protection device according to the relative value indicators, wherein the larger the calculation values of the relative value indicators are, the more perfect all the aspects of the protection device are, and the higher the reliability is. The indicator system can comprehensively evaluate the reliability of the relay protection device and is widely applied to relay protection device maintenance management personnel and relay protection device manufacturers.

Description

A kind of microcomputer protective relay device reliability evaluation index system

Technical field

The present invention relates to a kind of Power System Reliability assessment indicator system, particularly a kind of microcomputer protective relay device can By property assessment indicator system.

Background technology

Relay protection is the first line of defence that power system security is ensured, can relay protection correctly reliably work, right Operation of Electric Systems has great impact.In large-scale interconnected power system, Local Accidents may cause the large area of whole system to stop Electricity, and with the expansion of power system scale, the probability that accident occurs also can increase.In August, 2003 beautiful increasing of 14 days is stopped The electric world is rare, and the productive life for causing the economic loss more than 30,000,000,000 dollars, nearly 50,000,000 population is subject to different degrees of shadow Ring, including aviation, communication, water supply, traffic even all many-sides such as social security occur in that chaotic even paralysis, and cause so The reason for great cascading failure is overload protection " correct " action of relay protection unexpectedly.4 days 22 November in 2006:10 (morals State's time), 8, West Europe country there occurs large area blackout, and this is a power outage of Europe most serious over 30 years, More than 1000 ten thousand people are affected.The very big vibrations of Germany or even European Countries are caused, more causing people can to interconnected network By the new attention and thinking of property.On July 30th, 2012 (India's time) early morning 2:33 or so, northern electrical network occurrence of large-area is stopped Electrification, loses load about 36000MW, affects population about 3.7 hundred million (accounting for India's total population about 30%).Afternoon 16 on the same day:00, electricity Net is returned to normal, but subsequently, afternoon 13 July 31 local time:00 or so, north India, east, northeast 3 Regional power grid occurrence of large-area power outage again, loses load about 48000MW, (accounts for India's total population to exceed more than 600,000,000 50%) people is affected, and is that most populous large-scale blackout is affected in world wide.About 20 hours after accident generation, 3 areas Domain electrical network restores electricity substantially.

Conventional accident is analyzed and is understood, some trans-regional large-scale blackouts are because that relay protection works mostly What the maloperation of personnel or the malfunction of automatic safety device or tripping caused, it is seen that relay protection is to safe operation of power system shadow Sound is huge, it is necessary to inquire into " margin of safety " of relay protection.Relay protection is the weight of Accident prevention extension or chain reaction Ensure, the assessment studied the reliability of protective relaying device and carry out science is particularly important.Protective relaying device conduct Power system the first line of defence, its reliability can not be ignored, but in academic research before this, the reliability of protective relaying device Property assessment adopts single index, relay protection cannot comprehensively and have accurately been evaluated, therefore, it is necessary to propose that one kind can The assessment indicator system of thoroughly evaluating microcomputer protective relay device reliability.

The content of the invention

For the problems referred to above, it is an object of the invention to provide one kind being capable of thoroughly evaluating microcomputer protective relay device reliability Assessment indicator system.

For achieving the above object, the present invention takes technical scheme below：A kind of microcomputer protective relay device reliability evaluation Index system, comprises the following steps：1) reliability index R of protection device is calculated；2) the quick-action index of protection device is calculated S；3) susceptiveness index L of protection device is calculated；4) the durability index N of protection device is calculated；5) dimension of protection device is calculated Repairing property index W；6) the economic index J of protection device is calculated；7) by index R, the calculating of S, L, N, W, J, obtaining The reliability evaluation index of different dimensions, these indexs are divided into reverse index and the positive class of index two, and all reverse indexs are turned Positive index is changed to, makes all of index that there is being equally directed to property；And calculated using relative value, all of positive index is turned Relative value's index is changed to, reliability evaluation, relative value are unified comprehensively to protective relaying device finally according to relative value's index The various aspects of the more big then protection device of the value of calculation of index are more perfect, and reliability is higher.

The step 1) in reliability index R be 11 class indexs meansigma methodss：

The 11 class index is as follows：

1. automatic safety device performance factor R₁：

Wherein, n_cFor protection device correct operation number of times, N_oFor protection device action total degree；

2. fault wave recording device records ripple serviceability rate R₂：

Wherein, n_LRipple number of times, N are correctly recorded for failure wave-recording_LFor total record wave number；

3. definite value area definite value checks abnormal rate R₃：

Wherein, n_DFor definite value exception number, N_numFor protection device total number, T₀To run the cumulative time, if in units of year, Then T₀=1；

4. Channel Test abnormal rate R₄：

Wherein, n_TFor channel abnormal number；

5. clock accuracy abnormal rate R₅：

Wherein, n_SFor clock exception number；

6. protection switch amount abnormal state rate R₆：

Wherein, n_KFor protection switch amount exception number；

7. fault rate R of protective relaying device₇：

Wherein, n_fFor the number of stoppages of protection device；

8. work success rate R₈：

Wherein, n_icoFor troubles inside the sample space correct operation number of times, n_ocoCorrectly it is failure to actuate number of times for external area error, n_mFor fault-free Malfunction number of times, n_msFor non-selective malfunction number of times, n_rFor tripping number of times；n_icoAnd n_ocoCalculated by equation below：

Therefore, work success rate R₈Can be expressed as：

9. fault-free malfunction rate R₉：

10. operational failure rate R₁₀：

Wherein, tripping rate is n_r/N_numT₀, malfunction rate is (n_m+n_ms)/(N_numT₀)；

Comprehensive crash rate R₁₁：

Wherein, n_mafFor the failure accumulative total found during maintenance, T_mafAccumulative, the T for scheduled maintenance time_mnsrStop stopping for failure Time cumulation.

The step 2) in quick-action index S be three class indexs meansigma methodss：

Wherein, S₁For single-phase near terminal fault most fast mute time, S₂For single-phase near terminal fault most slow mute time, S₃For electricity The quick resection rate of net failure.

The step 3) in susceptiveness index L be：

Wherein, K is sensitivity index, K₀Represent the minimum sensitivity of setting；The computing formula of sensitivity index K is：

For current quick, its sensitivity index requires to be more than 1.2；For time limit current quick break protection, its is sensitive Degree index request is more than 1.3；For time delay over-current protection, when as nearly back-up protection, its sensitivity index requires big In 1.3, used as during remote back-up protection, its sensitivity index requires to be more than 1.2；For distance protection, its sensitivity index is required More than 1.5.

The step 4) in durability index N be 5 kinds of indexs meansigma methodss：

5 kinds of indexs are as follows：

1. average life N₁：

Wherein, λ₀For protection device fault rate；

2. comprehensive mean time between failures N₂：

3. degree of unavailability N₃：

Wherein, μ₁For relay protection fault repair rate；

4. main protection operational percentage N₄：

5. running status N₅：

The step 6) in economic index J be three kinds of economic indicators meansigma methodss：

Three kinds of economic indicators are maintenance cost J₁, the available economic coefficient J of protection₂With Financial cost coefficient of reliability J₃, Wherein：

The available economic coefficient J of protection₂For：

J₂=1/ (p_se_jp_j+e_wp_w),

Wherein, p_sFor a line failure rate, e_jFor tripping loss, p_jFor tripping rate, e_wFor malfunction loss, p_wFor malfunction Rate；

Financial cost coefficient of reliability J₃For：

Wherein, C is the economic loss of protection device.

The step 7) in, the positive index includes automatic safety device performance factor R₁, fault wave recording device record Ripple serviceability rate R₂, work success rate R₈, the quick resection rate S of electric network fault₃, average life N₁, comprehensive mean time between failures N₂, main protection operational percentage N₄, running status N₅, service age reduction factor W₂, maintenance cost J₁Economic coefficient J available with protection₂； The reverse index includes that definite value area definite value checks abnormal rate R₃, Channel Test abnormal rate R₄, clock accuracy abnormal rate R₅, protect Shield on-off state abnormal rate R₆, protective relaying device fault rate R₇, fault-free malfunction rate R₉, operational failure rate R₁₀, comprehensive failure Rate R₁₁, the most fast mute time S of single-phase near terminal fault₁, the most slow mute time S of single-phase near terminal fault₂, degree of unavailability N₃, average maintenance Time W₁With Financial cost coefficient of reliability J₃。

The positive index and reverse index are converted to the computational methods of relative value's index：

Due to taking above technical scheme, it has advantages below to the present invention：1st, the present invention is as a result of a set of comprehensive Reliability evaluation index system, realize and examine closely from different perspectives protective relaying device, comprehensively evaluate protective relaying device Reliability, the maintenance management personnel etc. that can give protective relaying device provide data supporting.2nd, the present invention is as a result of phase Value is calculated, the different dimensions for reducing different dimensions evaluation index compare the inconvenience for bringing so that the relay of different year The different reliability indexs contrast of protection device becomes apparent from.3rd, the present invention refers to due to all of index is converted into into forward direction Mark, with being equally directed to property, has clearly reflected protective relaying device development year by year, and to relevant staff Feed back the weak link of protection device, further to improve protective relaying device.Thus the present invention can be widely applied to after Electrical protective device maintenance management personnel and protective relaying device manufacturer.

Specific embodiment

A kind of microcomputer protective relay device reliability evaluation index system that the present invention is provided, comprises the following steps：

1) reliability index R of protection device is calculated.

Reliability index R is protective relaying device reliability and selective general designation：Reliability refers to protection device, and this is moved Action when making, should not be failure to actuate during action；Selectivity is referred to be cut first by the protection or chopper of faulty equipment or circuit itself Except failure, when the protection or chopper tripping of faulty equipment or circuit itself, just allow by neighbouring device, the protection of circuit or Breaker fail protection cuts off failure, with the characteristics of not malfunction, not tripping.Reliability index R is the meansigma methodss of 11 class indexs：

Above-mentioned 11 class index is as follows：

1. automatic safety device performance factor R₁：

Wherein, n_cFor protection device correct operation number of times, N_oFor protection device action total degree.

2. fault wave recording device records ripple serviceability rate R₂：

Wherein, n_LRipple number of times, N are correctly recorded for failure wave-recording_LFor total record wave number.

3. definite value area definite value checks abnormal rate R₃：

Wherein, n_DFor definite value exception number, N_numFor protection device total number, T₀To run the cumulative time, if in units of year, Then T₀=1.

4. Channel Test abnormal rate R₄：

Wherein, n_TFor channel abnormal number.

5. clock accuracy abnormal rate R₅：

Wherein, n_SFor clock exception number.

6. protection switch amount abnormal state rate R₆：

Wherein, n_KFor protection switch amount exception number.

7. fault rate R of protective relaying device₇：

Wherein, n_fFor the number of stoppages of protection device.

8. work success rate R₈：

Wherein, n_icoFor troubles inside the sample space correct operation number of times, n_ocoCorrectly it is failure to actuate number of times for external area error, n_mFor fault-free Malfunction number of times, n_msFor non-selective malfunction number of times, n_rFor tripping number of times.At present, the failure of China's protective relaying device and operation number According to the running log for being derived from each transformer station more, its troubles inside the sample space correct operation frequency n_icoCorrectly it is failure to actuate with external area error secondary Number n_ocoIt is difficult to obtain, but say from the angle of Probability ＆ Statistics, each bar line fault number of times can be approximately considered quite, therefore n_icoWith n_ocoThe two can be calculated by equation below：

Therefore, work success rate R₈It is represented by：

9. fault-free malfunction rate R₉：

10. operational failure rate R₁₀(malfunction rate+tripping rate)

Wherein, tripping rate is p_j=n_r/N_numT₀, malfunction rate is p_w=(n_m+n_ms)/(N_numT₀)。

Comprehensive crash rate R₁₁：

Wherein, n_mafFor the failure accumulative total found during maintenance, T_mafAccumulative, the T for scheduled maintenance time_mnsrStop stopping for failure Time cumulation, according to DL-T 995-2006《Relay protection and power grid security automaton inspection procedure》Regulation, if periodic maintenance Cycle is 3 years, then T_mafWith T_mnsrCan be calculated by below equation：

Wherein, μ₁For relay protection fault repair rate, μ₂For relay protection periodical inspection repair rate, and μ₁=2μ₂, typically take μ₂= 0.5 time/day.

2) the quick-action index S of protection device is calculated.

Can the protection device quick-action index S refers to that protection device should be able to as soon as possible cut off short trouble, with protection Quickly with the characteristics of action, its value is the meansigma methodss of 3 class indexs：

Wherein, S₁For single-phase near terminal fault most fast mute time, S₂For single-phase near terminal fault most slow mute time, S₃For electricity The quick resection rate of net failure.

3) susceptiveness index L of protection device is calculated.

Described device susceptiveness index L referred to when equipment or circuit are broken down in protection domain, protection device The nargin of the correct operation ability having, the index is divided into current protection and the class of distance protection two, and wherein current protection includes electricity Stream fast tripping protection, time limit current quick break protection and time delay over-current protect three kinds.Susceptiveness index L is in the present invention：

Wherein, K is sensitivity index, K₀Represent the minimum sensitivity of setting.The computing formula of sensitivity index K for：

For current quick, its sensitivity index requires to be more than 1.2；For time limit current quick break protection, its is sensitive Degree index request is more than 1.3；For time delay over-current protection, when as nearly back-up protection, its sensitivity index should be greater than 1.3, used as during remote back-up protection, its sensitivity index should be greater than 1.2；For distance protection, its sensitivity index should be greater than 1.5。

4) the durability index N of protection device is calculated.

The durability index N of device is used for characterizing life-span and the health condition of equipment, can directly reflect the state water of equipment Flat, its value is the meansigma methodss of 5 class indexs：

Above-mentioned 5 class index is as follows：

1. average life (MTTF) N₁：

Wherein, λ₀For protection device fault rate.

2. comprehensive mean time between failures N₂：

3. degree of unavailability N₃：

4. main protection operational percentage N₄：

5. running status N₅：

Running status N₅When protection device be in normal condition when be taken as 1, in attention state when be taken as 2/3, in different Often it is taken as 1/3 during state.At present, probability of the protection device that China's Statistical is obtained in general defect state is 0.867 time/hundred In platform year, be 0.707 time/100 year in critical defect and major defect shape probability of state, is filled respectively as protection is calculated Put the weight in attention state or abnormality.Due to protection device in normal condition probability in most of the cases without Method is directly calculated, therefore the present invention is by the performance factor R of protection device₁Be approximately protection device in normal condition when Probability, and then obtain running status N of protection device₅For：

5) the Maintainability index W of protection device is calculated.

The Maintainability index W of protection device refers to the meansigma methodss of 2 class indexs：

Above-mentioned 2 class index is as follows：

1. MTTR W₁：

2. service age reduction factor W₂：

Service age reduction factor W₂The ability of certain time point for making equipment return to before maintenance is referred to Jing after maintenance, and the value is Jing Numerical value is tested, 0.95 is typically taken, i.e.,

W₂=0.95 (27)

6) protection device economic index J is calculated, its value is the meansigma methodss of 3 class economic indicators：

Above-mentioned 3 class economic indicator is maintenance cost J₁, the available economic coefficient J of protection₂With Financial cost coefficient of reliability J₃, Wherein：

The available economic coefficient J of protection₂For：

J₂=1/ (p_se_jp_j+e_wp_w) (29)

Wherein, p_sFor a line failure rate, e_jFor tripping loss, p_jFor tripping rate, e_wFor malfunction loss, p_wFor malfunction Rate；

Financial cost coefficient of reliability J₃For：

Wherein, C is the economic loss of protection device.

7) by the way that to These parameters R, the calculating of S, L, N, W, J, the reliability evaluation index of different dimensions can be obtained, this A little indexs can be divided into reverse index and the positive class of index two, and all reverse indexs are converted to positive index by the present invention, make to own Index there is being equally directed to property, and because the evaluation index of different dimensions has a different dimensions, thus the present invention is adopted Relative value calculates, and all of positive index is converted to into relative value's index, finally according to relative value's index to protective relaying device Unified reliability evaluation comprehensively, namely the various aspects of the more big then protection device of the value of calculation of relative value's index are more perfect, Reliability is higher.

Above-mentioned positive index refers to that the reliability of the bigger protection device of value of calculation is higher, and positive index includes：Safety automation Device performance factor R₁, fault wave recording device record ripple serviceability rate R₂, work success rate R₈, the quick resection rate S of electric network fault₃, it is flat Equal life-span N₁, comprehensive mean time between failures N₂, main protection operational percentage N₄, running status N₅, service age reduction factor W₂、 Maintenance cost J₁Economic coefficient J available with protection₂.Above-mentioned reverse index refers to that the reliability of the bigger protection device of value of calculation is lower, Reverse index includes：Definite value area definite value verification abnormal rate R₃, Channel Test abnormal rate R₄, clock accuracy abnormal rate R₅, protection open Measure abnormal state rate R in pass₆, protective relaying device fault rate R₇, fault-free malfunction rate R₉, operational failure rate R₁₀, comprehensive crash rate R₁₁, the most fast mute time S of single-phase near terminal fault₁, the most slow mute time S of single-phase near terminal fault₂, degree of unavailability N₃, average maintenance when Between W₁With Financial cost coefficient of reliability J₃.All indexs to make calculating are respectively provided with being equally directed to property, and the present invention will be all of The relative value of reverse index is inverted so that all of reverse index is converted to positive index.Relative values refer at last with a certain Year calculated reliability evaluation index as reference value, the reliability evaluation index that its another year calculates respectively with reference value phase Than further obtaining its relative value, computing formula is：

Thus the computational methods that above-mentioned positive index and reverse index are converted to relative value's index are：

Below using certain regional power grid protective relaying device as one embodiment of the present of invention, microcomputer relay of the present invention is protected Protection unit reliability evaluation index system is described in further detail.

The data of the protective relaying device of the regional power grid are investigated, data below is obtained (such as the institute of 1～table of table 3 Show).

1 2001～2003 years protection device action effect statistics of table

The ruuning situation of 2 2001～2003 years fault oscillographs of table

	Calendar year 2001	2002	2003
				Total record wave number NL	6066	5764	6245
Failure wave-recording correctly records ripple frequency nL	5987	5699	6164

3 2001～2003 years protection device historic defects records of table

	Calendar year 2001	2002	2003
				Definite value exception number nD	0	0	0
Channel abnormal number nT	2	2	5
				Clock exception number nS	0	0	0
Switching value exception number nK	4	3	6
				Plant failure frequency nf	8	8	15

Additionally, according to statistics, microcomputer protective relay device in 2001～2003 years microcomputer protective relay device fault rates successively For 0.72 time/100 year, 0.59 time/100 year and 0.49 time/100 year；Single-phase near terminal fault in quick-action index S Most fast mute time S₁It is followed successively by 40ms, 40ms, 30ms, the most slow mute time S of single-phase near terminal fault₂Be followed successively by 110ms, 100ms, 100ms, the quick resection rate S of electric network fault₃It is followed successively by 99.38%, 99.20%, 99.13%；In durability index N Main protection operational percentage N₄It is followed successively by 99.92%, 100%, 99.63%；MTTR W in Maintainability index W₁Respectively For 8.38 hours, 7.65 hours, 5.36 hours, the failure accumulative total n found during maintenance_maf=1.

1) on the basis of the reliability index of calendar year 2001, reliability index R for counting each time for obtaining is following (such as table 4 It is shown).

Table reliability index R statistical result in 4 2001～2003 years

2) the quick-action index S in each time that statistics is obtained is following (as shown in table 5).

Table quick-action index S statistical result in 5 2001～2003 years

3) susceptiveness index L in each time that statistics is obtained is satisfied by the minimum requirements of sensitivity coefficient, therefore L=1.

4) the durability index N in each time that statistics is obtained is following (as shown in table 6).

Table durability index N statistical results in 6 2001～2003 years

5) the Maintainability index W in each time that statistics is obtained is following (as shown in table 7).

Table Maintainability index W statistical results in 7 2001～2003 years

6) go bail for protection unit tripping loss e_jFor 400,000 yuan, e is lost in malfunction_wFor 200,000 yuan, a line failure rate p_sFor 0.2737 times/year, tripping rate p of -2003 years calendar year 2001s_jRespectively 0.095,0.158,0.101 time/100 years, malfunction rate p_w For 0.189,0.238,0.067 time/100 year.The economic index J in each time that statistics is obtained is following (as shown in table 8).

Table economic index J statistical results in 8 2001～2003 years

The operation and maintenance level that can be seen that China's protective relaying device from above-mentioned statistical result is raised year by year, and relay is protected Protection unit processes the ability of power grid accident and improves year by year, and the performance of protective relaying device itself is become better and better, protective relaying device Operation maintenance cost it is more and more economical.From the point of view of reliability index R, due to the operational failure rate of protection device in 2002 it is obvious It is more low than former years, cause its global reliability index to decline, take a turn for the better at 2003, in the reliability index of protection device The trend of liter is obvious；From the point of view of inside the device, protection definite value, clock abnormal conditions are more rare, and passage, switching value failure are more Frequently；Action situation apparently, the motional success rate of protection device also more and more higher, occur malfunction, tripping number of times it is fewer and feweri. From the point of view of quick-action index S, its index is raised year by year, shows that China's protective relaying device quickly cuts off the ability of failure and adds year by year By force, this is not only because improving in principle also in that there is the progress on equipment manufacturing, on the whole, quick-action index S Lifting be conducive to the safe and stable operation of power system.From the point of view of durability index N, its index is raised year by year, and raises water It is flat very fast, show that China's power industry operation and maintenance level has been strengthened, equipment life has extended, the technical ability of operation maintenance personnel with Quality is improved year by year.From the point of view of Maintainability index W, its index is raised year by year, and this is also the annual interruption maintenance of protective relaying device One of time reduces year by year, and protection operational percentage is the reason for increase year by year.From the point of view of economic index J, its index is raised year by year, is said Bright China's protective relaying device cost of overhaul has downward trend year by year, it is worth pointing out that the index is built upon every year Equipment lose expense, maintenance cost, labour cost etc. it is constant in the case of, practical situation may disagree.

Above-described embodiment is only the present invention preferably specific embodiment, but protection scope of the present invention is not limited to This, every equivalents carried out on the basis of technical solution of the present invention and improvement should not exclude the protection in the present invention Outside scope.

Claims (7)

1. a kind of microcomputer protective relay device reliability evaluation index system, comprises the following steps：

1) reliability index R of protection device is calculated；

Reliability index R is the meansigma methodss of 11 class indexs：

$R=\frac{1}{11}\underset{i=1}{\overset{11}{\Σ}}{R}_i,$

The 11 class index is as follows：

1. automatic safety device performance factor R₁：

$R_1=\frac{n_c}{N_o},$

Wherein, n_cFor protection device correct operation number of times, N_oFor protection device action total degree；

2. fault wave recording device records ripple serviceability rate R₂：

$R_2=\frac{n_L}{N_L},$

Wherein, n_LRipple number of times, N are correctly recorded for failure wave-recording_LFor total record wave number；

3. definite value area definite value checks abnormal rate R₃：

$R_3=\frac{n_D}{N_{num}{T}_0},$

Wherein, n_DFor definite value exception number, N_numFor protection device total number, T₀To run the cumulative time, if in units of year, T₀ =1；

4. Channel Test abnormal rate R₄：

$R_4=\frac{n_T}{N_{num}{T}_0},$

Wherein, n_TFor channel abnormal number；

5. clock accuracy abnormal rate R₅：

$R_5=\frac{n_S}{N_{num}{T}_0},$

Wherein, n_SFor clock exception number；

6. protection switch amount abnormal state rate R₆：

$R_6=\frac{n_K}{N_{num}{T}_0},$

Wherein, n_KFor protection switch amount exception number；

7. fault rate R of protective relaying device₇：

$R_7=\frac{n_f}{N_{num}{T}_0},$

Wherein, n_fFor the number of stoppages of protection device；

8. work success rate R₈：

$R_8=\frac{n_{ico}+n_{oco}}{n_{ico}+n_{oco}+n_m+n_{ms}+n_r},$

Wherein, n_icoFor troubles inside the sample space correct operation number of times, n_ocoCorrectly it is failure to actuate number of times for external area error, n_mFor fault-free malfunction Number of times, n_msFor non-selective malfunction number of times, n_rFor tripping number of times；n_icoAnd n_ocoThe two is calculated by equation below：

$\left\{\begin{array}{c}{n}_{ico}=n_c-n_r\\ n_{oco}=n_f-n_{ms}\end{array}\right.,$

Therefore, work success rate R₈Can be expressed as：

$R_8=\frac{n_c+n_f-n_{ms}-n_r}{n_c+n_f+n_m};$

9. fault-free malfunction rate R₉：

$R_9=\frac{n_m}{N_{num}{T}_0},$

10. operational failure rate R₁₀：

$R_{10}=\frac{n_r+n_m+n_{ms}}{N_{num}{T}_0},$

Wherein, tripping rate is n_r/N_numT₀, malfunction rate is (n_m+n_ms)/(N_numT₀)；

Comprehensive crash rate R₁₁：

$R_{11}=\frac{n_{maf}}{N_{num}(T_0+T_{maf}+T_{mnsr})},$

Wherein, n_mafFor the failure accumulative total found during maintenance, T_mafAccumulative, the T for scheduled maintenance time_mnsrStop the not time for failure It is accumulative；

2) the quick-action index S of protection device is calculated；

3) susceptiveness index L of protection device is calculated；

4) the durability index N of protection device is calculated；

5) the Maintainability index W of protection device is calculated；

6) the economic index J of protection device is calculated；

7) by index R, the calculating of S, L, N, W, J, obtaining the reliability evaluation index of different dimensions, these indexs point For reverse index and the positive class of index two, all reverse indexs are converted to into positive index, make all of index that there is identical Directivity；And calculated using relative value, all of positive index is converted to into relative value's index, finally according to relative value's index pair Protective relaying device is unified reliability evaluation, the various aspects of the more big then protection device of value of calculation of relative value's index comprehensively More perfect, reliability is higher.

2. a kind of microcomputer protective relay device reliability evaluation index system as claimed in claim 1, it is characterised in that：It is described Step 2) in quick-action index S be three class indexs meansigma methodss：

$S=\frac{1}{3}(S_1+S_2+S_3),$

Wherein, S₁For single-phase near terminal fault most fast mute time, S₂For single-phase near terminal fault most slow mute time, S₃For electrical network event Hinder quick resection rate.

3. a kind of microcomputer protective relay device reliability evaluation index system as claimed in claim 1 or 2, it is characterised in that： The step 3) in susceptiveness index L be：

$L=min\{\frac{K}{K_0},1\},$

Wherein, K is sensitivity index, K₀Represent the minimum sensitivity of setting；The computing formula of sensitivity index K is：

For current quick, its sensitivity index requires to be more than 1.2；For time limit current quick break protection, its sensitivity refers to Mark requires to be more than 1.3；For time delay over-current protection, when as nearly back-up protection, its sensitivity index requires to be more than 1.3, used as during remote back-up protection, its sensitivity index requires to be more than 1.2；For distance protection, its sensitivity index requires big In 1.5.

4. a kind of microcomputer protective relay device reliability evaluation index system as claimed in claim 1 or 2, it is characterised in that： The step 4) in durability index N be 5 kinds of indexs meansigma methodss：

$N=\frac{1}{5}\underset{i=1}{\overset{5}{\Σ}}{N}_i;$

5 kinds of indexs are as follows：

1. average life N₁：

$N_1=\frac{1}{{\mathrm{\λ}}_0}=\frac{1}{R_7},$

Wherein, λ₀For protection device fault rate；

2. comprehensive mean time between failures N₂：

$N_2=\frac{T_0+T_{maf}+T_{mnsr}}{n_m+n_{ms}+n_r+n_{maf}},$

3. degree of unavailability N₃：

$N_3=\frac{{\mathrm{\λ}}_0}{{\mathrm{\λ}}_0+{\mathrm{\μ}}_1}=\frac{R_7}{R_7+{\mathrm{\μ}}_1},$

Wherein, μ₁For relay protection fault repair rate；

4. main protection operational percentage N₄：

5. running status N₅：

$\begin{array}{c}{N}_5=R_1+(1-R_1)\×\frac{0.867}{0.867+0.707}\×\frac{2}{3}+(1-R_1)\×\frac{0.707}{0.867+0.707}\×\frac{1}{3}\\ =\frac{2.281R_1+2.441}{4.722}\end{array}.$

5. a kind of microcomputer protective relay device reliability evaluation index system as claimed in claim 1, it is characterised in that：

The step 6) in economic index J be three kinds of economic indicators meansigma methodss：

$J=\frac{1}{3}(J_1+J_2+J_3),$

Three kinds of economic indicators are maintenance cost J₁, the available economic coefficient J of protection₂With Financial cost coefficient of reliability J₃, its In：

The available economic coefficient J of protection₂For：

J₂=1/ (p_se_jp_j+e_wp_w),

Wherein, p_sFor a line failure rate, e_jFor tripping loss, p_jFor tripping rate, e_wFor malfunction loss, p_wFor malfunction rate；

Financial cost coefficient of reliability J₃For：

$J_3=\frac{C}{1-\left(\frac{{R_{10}}^2+{N_3}^2}{R_{10}+N_3}\right)}$

Wherein, C is the economic loss of protection device；N₃For degree of unavailability.

6. a kind of microcomputer protective relay device reliability evaluation index system as claimed in claim 1, it is characterised in that：It is described Step 7) in, the positive index includes automatic safety device performance factor R₁, fault wave recording device record ripple serviceability rate R₂, work Make success rate R₈, the quick resection rate S of electric network fault₃, average life N₁, comprehensive mean time between failures N₂, main protection Operational percentage N₄, running status N₅, service age reduction factor W₂, maintenance cost J₁Economic coefficient J available with protection₂；The reverse index Abnormal rate R is checked including definite value area definite value₃, Channel Test abnormal rate R₄, clock accuracy abnormal rate R₅, protection switch amount state Abnormal rate R₆, protective relaying device fault rate R₇, fault-free malfunction rate R₉, operational failure rate R₁₀, comprehensive crash rate R₁₁, it is single-phase near The most fast mute time S of end failure₁, the most slow mute time S of single-phase near terminal fault₂, degree of unavailability N₃, MTTR W₁And Jing Ji cost coefficient of reliability J₃。

7. a kind of microcomputer protective relay device reliability evaluation index system as claimed in claim 1, it is characterised in that：It is described Positive index and reverse index are converted to the computational methods of relative value's index：