CN103500288A - Medium voltage distribution network reliability evaluation method based on regional level lead flow channel - Google Patents

Abstract

The invention discloses a medium voltage distribution network reliability evaluation method based on a regional level lead flow channel. A first layer of region division is carried out through a breaker, a disconnecting switch, an interconnection switch and other elements reflecting power supply features and power supply shifting features according to the power supply features and the power supply shifting features of the power distribution network, parenting subregions are formed, a lead flow channel table is formed for each parenting subregion with the passed breaker, disconnecting switch and interconnection switch as nodes according to the power supply path of the power supply of each parenting subregion, and therefore the failure consequence type of each parenting subregion is determined. For each parenting subregion, a second-level subregion of each parenting subregion is formed with a fuse as a demarcation point. According to the connecting relation of the second-level subregions and the lead flow channel tables of the parenting subregions, the reliability indexes of the parenting subregions and the load points of the parenting subregions are evaluated, the power supply reliability indexes of all the parenting subregions are synthesized to form the power supply reliability index of the power distribution network, and the power supply reliability evaluation of the power distribution network is achieved.

Description

A kind of reliability assessment method for medium voltage distribution network based on level zone tidal inlet

Technical field

The invention belongs to medium voltage distribution network Reliability Evaluation category.

Background technology

Along with the development of national economy, the scale of power distribution network is increasing, and structure is also day by day complicated, and power consumer is also more and more higher to the requirement of power supply reliability.For power supply enterprise, find the weak link in power distribution network, limited fund is improved to greatest extent to the power supply reliability of power distribution network, be its significant problem faced.Simultaneously, in daily power distribution network operational management, by the reliability level of assessment power distribution network, the overhaul technological transformation that can effectively formulate power distribution network, promote the raising of reliability management of power supply level, has important reality and economic implications.

At present, the distribution network reliability appraisal procedure mainly contains analytical method and the large class of simulation two.Analytical method is mainly the relation of setting up between element and system, by formula, calculates, and obtains reliability index.Analytical method has adopted strict mathematical measure, clear physics conception, and the accuracy of calculating is high.But, along with the expansion of power distribution network scale, computation complexity also sharply increases.Common analytic method has fault mode and consequences analysis method, Equivalent Network method, minimal path method, Equivalent Network method and state-space method etc.The method that represents of simulation is mainly Monte Carlo method, the main research idea of Monte Carlo simulation approach is the probability model of model equipment and system, make their parameter equal the solution of problem, then calculate the statistical nature of required parameter by the sampling experiment to model, finally provide solved approximate value.The characteristics of the method are very flexible, are not subject to the restriction of system scale, and can provide the probability distribution of reliability index, but they are consuming time many and precision is not high.

The present invention proposes a kind of reliability assessment method for medium voltage distribution network based on level zone tidal inlet, according to the supplied character of power distribution network with turn supplied character, with its supplied characters of reflection such as isolating switch, disconnector, interconnection switches with turn the element of supplied character, carrying out the ground floor zone divides, form the parent subregion of power distribution network, to each parent subregion, power source path according to its power supply, take by way of isolating switch, interconnection switch, interconnection switch be node, form its tidal inlet table, thereby determine each parent subregion failure effect type.To every sub regions, take fuse as separation, form the secondary subregion of each parent subregion.Turn the power supply decision set according to the annexation of secondary subregion and power distribution network, the reliability index of assessment parent subregion and load point thereof, the power supply reliability index of comprehensive all parent subregions, form the power supply reliability index of power distribution network, realizes the Reliability Evaluation of power distribution network.

Summary of the invention

In order efficiently, accurately to realize the Reliability Evaluation of power distribution network, the present invention proposes a kind of reliability assessment method for medium voltage distribution network based on level zone tidal inlet, its step is as follows:

A kind of reliability assessment method for medium voltage distribution network based on level zone tidal inlet, feature of the present invention is:

1) by sync cap, gather the related data in the distribution generalized information system, the initialization medium voltage distribution network network information comprises: transformer station's information, line information, switching information, information on load;

2) by power supply reliability information management platform (the power supply reliability infosystem that the whole nation is unified), adopt the historical data of nearest 3-5, initialization wire (bare conductor, insulated conductor, cable), substation transformer, isolating switch, disconnector, these primary element unit basis information of fuse, comprise failure rate, average time for repair of breakdowns;

3) take isolating switch, disconnector, interconnection switch is separation, power distribution network is carried out to the ground floor zone and divide, and forms the parent subregion, is designated as D _fi(Fi is the parent subarea number), to belonging to same D _ficell (on-off element, circuit and load), same supplied character is arranged and turns supplied character;

4) with D _fifor elementary cell, take isolating switch, disconnector, interconnection switch is the tidal inlet node, forms each D _fithe tidal inlet table, and definite D _fihigher level's regional ensemble and subregion; According to load capacity, the user gradation of tidal inlet table and regional, that sets up power distribution network turns the power supply decision set;

5) to each D _fi, take fuse as separation, form D _fithe secondary subregion, D _fithe secondary subregion comprise two types, load point (from the fuse to the substation transformer) piecemeal and bridge piecemeal (D _fithe module that all fuses comprise);

6) to D _fi, by power distribution network turn the power supply decision set, determine that when stop transport in the higher level zone, it turns electric power thus supplied;

7) calculate D according to the piecemeal situation of secondary subregion _fithe inherent reliability index; Turn electric power thus supplied according to it, calculate the reliability index of higher level's regional effect; According to the tripping situation of subregion entrance isolating switch, calculate the reliability index of its subregion impact;

8) assessment D _fiand the power supply reliability index of load point;

9) comprehensive all D _fiand load point power supply reliability index, the power supply reliability index of formation power distribution network.

The invention has the beneficial effects as follows, the characteristics of the method are very flexible, are not subject to the restriction of system scale, and can provide the probability distribution of distribution network reliability index, calculate simply, Evaluation accuracy is high, is applicable to the distribution network reliability assessment of engineering reality.

The accompanying drawing explanation

The level-1 area that Fig. 1 is power distribution network is divided schematic diagram;

Fig. 2 is a kind of reliability assessment method for medium voltage distribution network process flow diagram based on level zone tidal inlet of the present invention.

Embodiment

The present invention is a kind of reliability assessment method for medium voltage distribution network based on level zone tidal inlet, and its embodiment is:

1), by sync cap, gather the related data in the distribution generalized information system, the initialization medium voltage distribution network network information: transformer station's information, line information, switching information, information on load;

2) by power supply reliability information management platform (the power supply reliability infosystem that the whole nation is unified), adopt the historical data of nearest 3 years, the primary element unit basis information such as initialization wire (bare conductor, insulated conductor, cable etc.), substation transformer, isolating switch, disconnector, fuse, mainly comprise failure rate, average time for repair of breakdowns, the primary element operation time limit;

3) with isolating switch, disconnector, interconnection switch, power distribution network is carried out to the division of parent subregion, initialization parent subregion information, comprise border parent subarea number, isolating switch set, entrance isolating switch, number of users, power supply capacity etc.;

4) take fuse and as node, the parent subregion is divided, form the secondary subregion of each parent subregion, comprise bridge piecemeal and load point piecemeal, and the relevant information of initialization secondary subregion: element forms, the master data parameter of element;

5), to each parent subregion, form its control the trend channel table and standby tidal inlet table;

6) according to the tidal inlet table, comprehensively each regional power supply capacity and user gradation, what form power distribution network turns the power supply decision set;

7) according to the element of bridge piecemeal and load piecemeal, form, calculate the inherent reliability index of each parent subregion and load piecemeal, according to the inherent reliability index of subregion and the tripping probability of isolating switch, calculate the power supply reliability index of subregion impact, according to power distribution network turn the power supply decision set, calculate the power supply reliability index of higher level's regional effect;

8) calculate each zone and load power supply reliability index thereof;

9) according to the power supply reliability index of each zone, load, the power supply reliability index of computing system, form final evaluating reliability of distribution network result.

It is separation that isolating switch, disconnector, interconnection switch are take in the present invention, power distribution network is carried out to the ground floor zone and divide, and forms the parent subregion.The circuit of certain power supply administration of take is example, and as shown in Figure 1, Bi means isolating switch, and Si means disconnector, and N/O means interconnection switch, and Fi means fuse.

Division by the first level, formed D _f1to D _f8eight parent subregions.To each D _fi, can use following equation expression:

D _fi={ num _fi, entry switch element, { boundary switch set }, λ _dFi, γ _dFi}

Wherein, λ _dFimean regional D _fifailure rate, γ _dFimean regional D _fiaverage time for repair of breakdowns.

To each parent subregion, take fuse as separation, carry out Further Division, form this regional sub-block, sub-block is mainly divided two types: the series connection part backbone bridges piecemeal comprised by isolating switch, disconnector, interconnection switch and fuse; Load piecemeal by circuit, substation transformer series connection.Each sub-block can be expressed as:

D _sij={ num _sij, parent subregion, { boundary switch set }, λ _sFij, γ _sFij}

Wherein, λ _sFijmean regional D _fisub-block D _sijfailure rate, γ _dFijmean regional D _fisub-block D _sijaverage time for repair of breakdowns.

For all sub-blocks of each parent subregion, other parent subregions all are consistent on its failure effect impact.

1) generation of tidal inlet table.From the outlet breaker of the power supply point of power distribution network, according to its direction of tide, search for the tidal inlet of each parent subregion, with its reach this zone the Switching Elements of process mean.Take the power distribution network shown in figure mono-as example.Can obtain following tidal inlet table:

$\left\{\begin{array}{c}{R}_{\mathrm{DF}1}=\left\{B1\right\}\\ R_{\mathrm{DF}2}=\{B1,B2\}\\ R_{\mathrm{DF}3}=\{B1,B2,S1,S3\}\\ R_{\mathrm{DF}4}=\{B1,B2,B4\}\\ R_{\mathrm{DF}5}=\{B1,B2,B4,B5\}\\ R_{\mathrm{DF}6}=\{B1,B2,S1\}\\ R_{\mathrm{DF}7}=\{B1,B2,S1,B6\}\\ R_{\mathrm{DF}8}=\{B1,B2,S1,B6,B7\}\end{array}\right.$

If power distribution network has a plurality of power supply points, according to same mode, obtain its all standby tidal inlet table.To any one parent subregion D _fi, remove last element of its tidal inlet, corresponding zone is D _fithe father zone, get rid of successively last element, obtain D _fiall higher level zones.For the tidal inlet table of above formula, D _f3the father zone be D _f6, that is to say D _f3d _f6subregion.D _f3the higher level zone is D _f6, D _f2, D _f1.

2) each regional reliability index is calculated.

Each regional reliability index is divided into two large classes: district system index and load reliability index.The district system index mainly comprises regional equivalent fault rate, equivalence idle time and equivalent fault repair time etc.The load reliability index mainly comprises: the average frequency of power cut of loading, load System average interruption duration, Suo Xie SAID, load loss of outage capacity etc.

(1) each regional inherent reliability index is calculated

Each zone is all to form a radial distribution network by backbone bridges piecemeal and load piecemeal, therefore can calculate its inherent reliability index by radial distribution networks Equivalent Network model.For regional D _fi, its reliability index is:

$\left\{\begin{array}{c}{\mathrm{\λ}}_{\mathrm{Fi}}^1=\underset{j}{\mathrm{\Σ}}{\mathrm{\λ}}_{\mathrm{Fij}}+\underset{k}{\mathrm{\Σ}}{p}_{\mathrm{Fik}}{\mathrm{\λ}}_{\mathrm{FFik}}\\ T_{\mathrm{Fi}}^1=\underset{j}{\mathrm{\Σ}}{\mathrm{\λ}}_{\mathrm{Fij}}{r}_{\mathrm{Fij}}+\underset{k}{\mathrm{\Σ}}{p}_{\mathrm{Fik}}{\mathrm{\λ}}_{\mathrm{FFik}}{r}_{\mathrm{FFik}}\end{array}\right.$

Wherein, for regional D _fiintrinsic equivalent fault rate,

for regional D _fiintrinsic equivalence idle time, λ _fijand r _fijbe respectively regional D _fiseries element equivalent fault rate and equivalent fault repair time of backbone bridges piecemeal, λ _fFikand r _fFikbe respectively D _fiequivalent fault rate and equivalent fault repair time of load piecemeal k, p _fikfor D _fithe unreliable fusing probability of fuse of load piecemeal k.For D _fieach piecemeal, be all to have each primary element to be in series, therefore, its equivalent fault rate can obtain in the failure rate summation by each element, establishes certain piecemeal and is comprised of n element, λ _eithe failure rate that means its i element, r _eithe average time for repair of breakdowns that means its i element, the equivalent fault rate of this piecemeal and equivalent fault can obtain by following formula repair time:

(2) reliability index of subregion impact is calculated

The impact of subregion mainly refers to that certain regional subregion is owing to going the tripping of entry switch element to cause this zone to be stopped transport.Suppose certain regional D _fithe n sub regions is arranged, be respectively D _{fi (1)}, D _{fi (2)}..., D _{fi (n)}, the intrinsic equivalent fault rate of each sub regions is respectively

,

the intrinsic equivalent idle time of each sub regions is respectively

the entrance isolating switch tripping probability of each sub regions is respectively p _{fi (1)}, p _{fi (2)}..., p _{fi (n)}thereby, can obtain D _fithe reliability index of subregion impact:

$\left\{\begin{array}{c}{\mathrm{\λ}}_{\mathrm{Fi}}^2=\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{p}_{\mathrm{Fi}\left(j\right)}{\mathrm{\λ}}_{\mathrm{Fi}\left(j\right)}\\ T_{\mathrm{Fi}}^2=\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{p}_{\mathrm{Fi}\left(j\right)}{\mathrm{\λ}}_{\mathrm{Fi}\left(j\right)}{T}_{\mathrm{Fi}\left(j\right)}\end{array}\right.$

(3) reliability index of higher level's regional effect is calculated

The reliability index of higher level's regional effect refers to as certain regional D _fihigher level zone while stopping transport, to D _fithe impact of reliability index, when main consideration is stopped transport when its higher level zone, D _fiwhether can realize turning power supply.

Consider D _fihigher level zone D _fj, work as D _fjduring stoppage in transit, D _fican not realize turning confession, so, D _fjstoppage in transit can directly cause D _fistoppage in transit, its reliability index can be directly delivered to D _fi, therefore have:

$\left\{\begin{array}{c}{\mathrm{\λ}}_{\mathrm{Fi}}^{3j}={\mathrm{\λ}}_{\mathrm{Fj}}^1\\ T_{\mathrm{Fi}}^{3j}=T_{\mathrm{Fj}}^1\end{array}\right.$

Work as D _fjduring stoppage in transit, D _fican realize turning confession, so, D _fjstoppage in transit affect D _fiidle time be the running time that turns power supply, therefore have:

The judgement that turns power supply can be carried out according to the power supply decision set that turns of power distribution network.Describe with the power distribution network shown in Fig. 1, for this power distribution network, can form standby tidal inlet table:

$\left\{\begin{array}{c}{R}_{\mathrm{DF}1}^{\′}=\{N/O,S1,B2\}\\ R_{\mathrm{DF}2}^{\′}=\{N/O,S1\}\\ R_{\mathrm{DF}3}^{\′}=\{N/O,B3\}\\ R_{\mathrm{DF}4}^{\′}=\{N/O,S1,B4\}\\ R_{\mathrm{DF}5}^{\′}=\{N/O,S1,B4,B5\}\\ R_{\mathrm{DF}6}^{\′}=\{N/O\}\\ R_{\mathrm{DF}7}^{\′}=\{N/O,B6\}\\ R_{\mathrm{DF}8}^{\′}=\{N/O,B6,B7\}\end{array}\right.$

As certain regional D _fiduring stoppage in transit, get its boundary switch set, if its boundary switch set and D _fjthe common factor of standby tidal inlet table be empty, D is described _fjnetwork structure, possess the condition of power supply of turning, otherwise do not possess the condition of power supply of turning.For instance, D _f2stop transport, its boundary set be combined into B2, S1, B4}, with its common factor non-NULL R ' arranged _dF1, R ' _dF4, R ' _dF5, with its common factor, being empty set has R ' _dF3, R ' _dF6, R ' _dF7, R ' _dF8, R ' is described _dF3, R ' _dF6, R ' _dF7, R ' _dF8possesses the condition of power supply of turning.

For possessing the zone that turns condition of power supply, need to, according to the power supply capacity situation of standby power supply, determine and turn the power supply decision set.Its decision process is as follows:

The first step, obtain the power supply capacity remaining of each regional power supply capacity and standby power supply;

Second step, determine the important level that each is regional.The highest important level of user that the important level in zone is this zone and subordinate zone thereof.Be divided into three grades, one-level is the highest, and three grades minimum.For instance, if regional D _f8all users are general resident, and its important level is 3, if contain the secondary responsible consumer, its important level is made as 2.When it is 2, to D _f7, due to D _f7d _f8the higher level zone, even D _f7middle user is all the general user, and its significance level is also 2.Be D _fiimportant level be:

The 3rd step, calculate to meet the block supply capacity that turns condition of power supply, if the All Ranges power supply capacity and be less than standby power supply power supply capacity remaining, illustrate that the satisfied zone that turns condition of power supply can turn confession; If the All Ranges power supply capacity and be greater than standby power supply power supply capacity remaining, illustrate and can only implementation section turn confession to the satisfied zone that turns condition of power supply.Part turns the power supply area that turns of power supply and is selected according to following principle: at first according to regional important level, and the zone that priority level is high; Secondly, the identical zone for important level, the large zone of preferential load capacity; The 3rd, take and allly turn the total load capacity of power supply area to be less than standby power supply power supply capacity remaining be condition, implement load transfer to greatest extent.

By said process, that just can set up power distribution network turns the power supply decision set.Thus, can obtain D _fithe reliability index of higher level's regional effect:

$\left\{\begin{array}{c}{\mathrm{\λ}}_{\mathrm{Fi}}^3=\underset{j}{\mathrm{\Σ}}{\mathrm{\λ}}_{\mathrm{Fi}}^{3j}\\ T_{\mathrm{Fi}}^3=\underset{j}{\mathrm{\Σ}}{\mathrm{\λ}}_{\mathrm{Fi}}^{3j}{T}_{\mathrm{Fi}}^{3j}\end{array}\right.$

(4) each regional reliability index is calculated

The reliability index of comprehensive three parts, can obtain regional D _fithe power supply reliability index:

$\left\{\begin{array}{c}{\mathrm{\λ}}_{\mathrm{Fi}}={\mathrm{\λ}}_{\mathrm{Fi}}^1+{\mathrm{\λ}}_{\mathrm{Fi}}^2+{\mathrm{\λ}}_{\mathrm{Fi}}^3\\ T_{\mathrm{Fi}}={\mathrm{\λ}}_{\mathrm{Fi}}^1+T_{\mathrm{Fi}}^1+{\mathrm{\λ}}_{\mathrm{Fi}}^2{T}_{\mathrm{Fi}}^2+{\mathrm{\λ}}_{\mathrm{Fi}}^3{T}_{\mathrm{Fi}}^3\\ {\mathrm{\γ}}_{\mathrm{Fi}}=T_{\mathrm{Fi}}/{\mathrm{\λ}}_{\mathrm{Fi}}\end{array}\right.$

Zone D _fieach load point reliability index be:

$\left\{\begin{array}{c}{\mathrm{\λ}}_{\mathrm{Fi}}^k={\mathrm{\λ}}_{\mathrm{Fik}}^1+{\mathrm{\λ}}_{\mathrm{Fi}}^2+{\mathrm{\λ}}_{\mathrm{Fi}}^3\\ T_{\mathrm{Fi}}^k={\mathrm{\λ}}_{\mathrm{Fik}}^1{T}_{\mathrm{Fik}}^1+{\mathrm{\λ}}_{\mathrm{Fi}}^2{T}_{\mathrm{Fi}}^2+{\mathrm{\λ}}_{\mathrm{Fi}}^3{T}_{\mathrm{Fi}}^3\\ {\mathrm{\γ}}_{\mathrm{Fi}}^k=T_{\mathrm{Fi}}^k/{\mathrm{\λ}}_{\mathrm{Fi}}^k\end{array}\right.$

Wherein, for regional D _fithe failure rate of load k,

average time for repair of breakdowns for load k.

for the indigenous fault rate of load k, it is by regional D _fibridge piecemeal and load k piecemeal equivalent fault rate obtain,

for the intrinsic average idle time of load k, it is by regional D _fibridge piecemeal and load k piecemeal equivalent fault rate and obtain equivalent fault repair time.

3) reliability index of computing system

Remember regional D _finumber of users be N _fi, the System average interruption frequency, Suo Xie SAIF of system is f _sAIFI, the System average interruption duration, Suo Xie SAID of system is T _sAIDI, user's System average interruption duration, Suo Xie SAID is T _cAIDI, the power supply reliability of system is P _aSAI, the reliability index of system is:

$\left\{\begin{array}{c}{f}_{\mathrm{SAIFI}}=\underset{i}{\mathrm{\Σ}}{\mathrm{\λ}}_{\mathrm{Fi}}{N}_{\mathrm{Fi}}/\underset{i}{\mathrm{\Σ}}{N}_{\mathrm{Fi}}\\ T_{\mathrm{SAIDI}}=\underset{i}{\mathrm{\Σ}}{T}_{\mathrm{Fi}}{N}_{\mathrm{Fi}}/\underset{i}{\mathrm{\Σ}}{N}_{\mathrm{Fi}}\\ T_{\mathrm{CAIDI}}=\underset{i}{\mathrm{\Σ}}{T}_{\mathrm{Fi}}{N}_{\mathrm{Fi}}/\underset{i}{\mathrm{\Σ}}{\mathrm{\λ}}_{\mathrm{Fi}}{N}_{\mathrm{Fi}}\\ P_{\mathrm{ASAI}}=(8760\×\underset{i}{\mathrm{\Σ}}{N}_{\mathrm{Fi}}-\underset{i}{\mathrm{\Σ}}{T}_{\mathrm{Fi}}{N}_{\mathrm{Fi}})/(8760\×\underset{i}{\mathrm{\Σ}}{N}_{\mathrm{Fi}})\end{array}\right..$

Claims (1)

1. the reliability assessment method for medium voltage distribution network based on level zone tidal inlet is characterized in that:

1) by sync cap, gather the related data in the distribution generalized information system, the initialization medium voltage distribution network network information comprises: transformer station's information, line information, switching information, information on load;

2) by the power supply reliability information management platform, adopt the historical data of nearest 3-5, initialization wire, substation transformer, isolating switch, disconnector, these primary element unit basis information of fuse, comprise failure rate, average time for repair of breakdowns;

3) take isolating switch, disconnector, interconnection switch is separation, power distribution network is carried out to the ground floor zone and divide, and forms the parent subregion, is designated as D _fiin formula, Fi is the parent subarea number, to belonging to same D _ficell, same supplied character is arranged and turns supplied character;

4) with D _fifor elementary cell, take isolating switch, disconnector, interconnection switch is the tidal inlet node, forms each D _fithe tidal inlet table, and definite D _fihigher level's regional ensemble and subregion; According to load capacity, the user gradation of tidal inlet table and regional, that sets up power distribution network turns the power supply decision set;

5) to each D _fi, take fuse as separation, form D _fithe secondary subregion, D _fithe secondary subregion comprise two types, load point from fuse to the substation transformer piecemeal and the bridge piecemeal be D _fithe module that all fuses comprise;

6) to D _fi, by power distribution network turn the power supply decision set, determine that when stop transport in the higher level zone, it turns electric power thus supplied;

7) calculate D according to the piecemeal situation of secondary subregion _fithe inherent reliability index; Turn electric power thus supplied according to it, calculate the reliability index of higher level's regional effect; According to the tripping situation of subregion entrance isolating switch, calculate the reliability index of its subregion impact;

8) assessment D _fiand the power supply reliability index of load point;

9) comprehensive all D _fiand load point power supply reliability index, the power supply reliability index of formation power distribution network.