CN103500288B - A kind of reliability assessment method for medium voltage distribution network based on level regions tidal inlet - Google Patents

Abstract

A kind of reliability assessment method for medium voltage distribution network based on level regions tidal inlet, the present invention is first according to the supplied character of power distribution network and turn supplied character, reflect its supplied character with chopper, isolation switch, interconnection switch etc. and turn the element of supplied character, carry out the division of ground floor region, form the parent subregion of power distribution network, to each parent subregion, power source path according to its power supply, with the chopper of approach, interconnection switch, interconnection switch for node, form its tidal inlet table, so that it is determined that each parent subregion failure effect type.To every sub regions, with fuse for separation, form two grades of subregions of each parent subregion.Annexation according to two grades of subregions and the tidal inlet table of parent subregion, the reliability index of assessment parent subregion and load point thereof, the power supply reliability index of comprehensive all parent subregions, forms the power supply reliability index of power distribution network, it is achieved the Reliability Evaluation of power distribution network.

Description

A kind of reliability assessment method for medium voltage distribution network based on level regions 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 the power supply reliability of power distribution network, is its significant problem faced.Meanwhile, in daily power distribution network operational management, by assessing the reliability level of power distribution network, it is possible to effectively formulate the overhaul technological transformation of power distribution network, promote the raising of reliability management of power supply level, there is important reality and economic implications.

At present, distribution network reliability appraisal procedure mainly has analytic method and the big class of simulation method two.Analytic method mainly sets up the relation between element and system, is calculated by formula, obtains reliability index.Analytic method have employed strict mathematical measure, clear physics conception, and the accuracy of calculating is high.But being as the expansion of power distribution network scale, computation complexity also sharply increases.Common analytic method has fault mode and consequences analysis method, network morals education, minimal path method, network morals education and state space method etc..The representative method of simulation method is mainly Monte Carlo method, the main research idea of Monte Carlo simulation approach is the probabilistic model initially setting up equipment and system, make their parameter solution equal to problem, then pass through the sampling experiment to model to calculate the statistical nature of required parameter, finally provide the approximation solved.Being characterized in that of the method is very flexible, not by 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 regions tidal inlet, supplied character according to power distribution network and turn supplied character, reflect its supplied character with chopper, isolation switch, interconnection switch etc. and turn the element of supplied character, carry out the division of ground floor region, form the parent subregion of power distribution network, to each parent subregion, power source path according to its power supply, with by way of chopper, interconnection switch, interconnection switch is for node, form its tidal inlet table, so that it is determined that each parent subregion failure effect type.To every sub regions, with fuse for separation, form two grades of subregions of each parent subregion.Annexation according to two grades of subregions and power distribution network turn power supply decision set, the reliability index of assessment parent subregion and load point thereof, the power supply reliability index of comprehensive all parent subregions, forms the power supply reliability index of power distribution network, it is achieved the Reliability Evaluation of power distribution network.

Summary of the invention

In order to efficiently, accurately 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 regions tidal inlet, and its step is as follows:

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

1) by sync cap, gather the related data in distribution generalized information system, initialize the medium voltage distribution network network information and include: substation information, line information, switching information, information on load；

2) by power supply reliability information management platform (the power supply reliability information system that the whole nation is unified), adopt the historical data of nearest 3-5, initialize wire (bare conductor, insulated conductor, cable), distribution transformer, chopper, isolation switch, these primary element unit basis information of fuse, including failure rate, average time for repair of breakdowns；

3) with chopper, isolation switch, interconnection switch for separation, power distribution network is carried out the division of ground floor region, forms parent subregion, be designated as D_Fi(Fi is parent subarea number), to belonging to same D_FiCell (switch element, circuit and load), have unified supplied character and turn supplied character；

4) with D_FiFor elementary cell, with chopper, isolation switch, interconnection switch for tidal inlet node, form each D_FiTidal inlet table, and determine D_FiHigher level's regional ensemble and subregion；According to tidal inlet table and the load capacity of regional, user gradation, that sets up power distribution network turns power supply decision set；

5) to each D_Fi, with fuse for separation, form D_FiTwo grades of subregions, D_FiTwo grades of subregions include two types, load point (from fuse to distribution transformer) piecemeal and bridge piecemeal (D_FiThe module that all fuses comprise)；

6) to D_Fi, by turn power supply decision set of power distribution network, it is determined that time stoppage in transit in higher level region, it turns electric power thus supplied；

7) D is calculated according to the piecemeal situation of two grades of subregions_FiInherent reliability index；Turn electric power thus supplied according to it, calculate the reliability index of higher level's regional effect；Tripping situation according to subregion entrance chopper, calculates 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, form the power supply reliability index of power distribution network.

The invention has the beneficial effects as follows, being characterized in that of the method is very flexible, not by the restriction of system scale, and the probability distribution of distribution network reliability index can be provided, calculating simple, Evaluation accuracy is high, it is adaptable to the distribution network reliability assessment that engineering is actual.

Accompanying drawing explanation

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

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

Detailed description of the invention

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

1) by sync cap, gather the related data in distribution generalized information system, initialize the medium voltage distribution network network information: substation information, line information, switching information, information on load；

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

3) with chopper, isolation switch, interconnection switch, power distribution network is carried out parent sub-zone dividing, initialize parent subregion information, including border parent subarea number, chopper set, entrance chopper, number of users, power supply capacity etc.；

4) for node, parent subregion is divided with fuse, form two grades of subregions of each parent subregion, including bridge piecemeal and load point piecemeal, and initialize the relevant information of two grades of subregions: element is constituted, the master data parameter of element；

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

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

7) constitute according to the element of bridge piecemeal and load piecemeal, calculate the inherent reliability index of each parent subregion and load piecemeal, inherent reliability index according to subregion and the tripping probability of chopper, calculate the power supply reliability index of subregion impact, the decision set of powering that turns according to power distribution network, the power supply reliability index of calculating higher level's regional effect；

8) each region and load power supply reliability index thereof are calculated；

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

Power distribution network, with chopper, isolation switch, interconnection switch for separation, is carried out the division of ground floor region, forms parent subregion by the present invention.For certain power supply administration circuit, as it is shown in figure 1, Bi represents that chopper, Si represent isolation switch, N/O represents interconnection switch, and Fi represents fuse.

By the division of the first level, define D_F1To D_F8Eight parent subregions.To each D_Fi, it is possible to express by equation below:

D_Fi={ num_Fi, entry switch element, { boundary switch set }, λ_DFi, γ_DFi}

Wherein, λ_DFiRepresent region D_FiFailure rate, γ_DFiRepresent region D_FiAverage time for repair of breakdowns.

To each parent subregion, with fuse for separation, carrying out Further Division, form the sub-block in this region, sub-block is point two types mainly: the part in series backbone bridges piecemeal comprised by chopper, isolation switch, interconnection switch and fuse；Load piecemeal by circuit, distribution 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_SFijRepresent region D_FiSub-block D_sijFailure rate, γ_DFijRepresent region D_FiSub-block D_sijAverage time for repair of breakdowns.

All sub-blocks for each parent subregion, its failure effect is affected and all keeps consistent by other parent subregions.

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, represent with the Switching Elements that it reaches this region passed.For the power distribution network shown in figure mono-.Following tidal inlet table can be obtained:

$\left\{\begin{array}{c}{R}_{DF1}=\left\{B1\right\}\\ R_{DF2}=\{B1,B2\}\\ R_{DF3}=\{B1,B2,S1,B3\}\\ R_{DF4}=\{B1,B2,B4\}\\ R_{DF5}=\{B1,B2,B4,B5\}\\ R_{DF6}=\{B1,B2,S1\}\\ R_{DF7}=\{B1,B2,S1,B6\}\\ R_{DF8}=\{B1,B2,S1,B6,B7\}\end{array}\right.$

If power distribution network has multiple power supply point, obtain its all of standby tidal inlet table according to same mode.To any one parent subregion D_Fi, remove last element of its tidal inlet, corresponding region is D_FiFather region, get rid of last element successively, obtain D_FiAll of higher level region.For the tidal inlet table of above formula, D_F3Father region be D_F6, say, that D_F3It is D_F6Subregion.D_F3Higher level region is D_F6、D_F2、D_F1。

2) each area reliability index calculates.

The reliability index in each region is divided into two big classes: district system index and load reliability index.District system index mainly includes the equivalent fault rate in region, equivalence idle time and equivalent fault repair time etc..Load reliability index specifically includes that the average frequency of power cut of load, load System average interruption duration, load loss of outage capacity etc..

(1) each region inherent reliability index calculates

Each region is all constituted 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 region D_Fi, its reliability index is:

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

Wherein,For region D_FiIntrinsic equivalent fault rate,For region D_FiIntrinsic equivalence idle time, λ_FijAnd r_FijRespectively region D_FiThe series element equivalent fault rate of backbone bridges piecemeal and equivalent fault repair time, λ_FFikAnd r_FFikRespectively D_FiThe equivalent fault rate of load piecemeal k and equivalent fault repair time, p_FikFor D_FiThe unreliable fusing probability of fuse of load piecemeal k.For D_FiEach piecemeal, be all have each primary element to be in series, therefore, its equivalent fault rate can be obtained by the summation of the fault rate of each element, if certain piecemeal is made up of n element, λ_eiRepresent the fault rate of its i-th element, r_eiRepresenting the average time for repair of breakdowns of its i-th element, equivalent fault rate and the equivalent fault of this piecemeal can be obtained by following formula repair time:

(2) reliability index of subregion impact calculates

The impact of subregion is primarily referred to as the subregion in certain region owing to going entry switch element tripping to cause stopping transport in this region.Assume certain region D_FiThere is n sub regions, respectively D_Fi(1)、D_Fi(2)、…、D_Fi(n), the intrinsic equivalent fault rate of each sub regions is respectively The intrinsic equivalence idle time of each sub regions is respectivelyThe entrance chopper tripping probability respectively p of each sub regions_Fi(1)、p_Fi(2)、…、p_Fi(n), such that it is able to obtain D_FiSubregion impact reliability index:

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

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

The reliability index of higher level's regional effect refers to as certain region D_FiHigher level region stop transport time, to D_FiThe impact of reliability index, mainly considers when stopping transport in its higher level region, D_FiWhether can realize turning power supply.

Consider D_FiHigher level region D_Fj, work as D_FjDuring stoppage in transit, D_FiCan not realize turning and supply, then, D_FjStoppage in transit can directly result in D_FiStoppage in transit, its reliability index can be directly delivered to D_Fi, so that

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

Work as D_FjDuring stoppage in transit, D_FiCan realize turning supplying, then, D_FjStoppage in transit affect D_FiIdle time be turn power supply an operating time so that

The judgement turning power supply can carry out according to the power supply decision set that turns of power distribution network.Illustrate with the power distribution network shown in Fig. 1, for this power distribution network, it is possible to form standby tidal inlet table:

$\left\{\begin{array}{c}{R}_{DF1}^{\′}=\{N/O,S1,B2\}\\ R_{DF2}^{\′}=\{N/O,S1\}\\ R_{DF3}^{\′}=\{N/O,B3\}\\ R_{DF4}^{\′}\{N/O,S1,B4\}\\ R_{DF5}^{\′}=\{N/O,S1,B4,B5\}\\ R_{DF6}^{\′}=\{N/O\}\\ R_{DF7}^{\′}=\{N/O,B6\}\\ R_{DF8}^{\′}=\{N/O,B6,B7\}\end{array}\right.$

As certain region D_FiDuring stoppage in transit, take 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 and turn condition of power supply, otherwise do not possess and turn condition of power supply.For example, D_F2Stop transport, its boundary set be combined into B2, S1, B4}, and the non-NULL that occurs simultaneously with it have R '_DF1、R′_DF4、R′_DF5, occuring simultaneously with it has R ' for empty set_DF3、R′_DF6、R′_DF7、R′_DF8, R ' is described_DF3、R′_DF6、R′_DF7、R′_DF8Possess and turn condition of power supply.

For possessing the region turning condition of power supply, it is necessary to the power supply capacity situation according to stand-by power supply, it is determined that turn power supply decision set.Its decision making process is as follows:

The first step, obtains the power supply capacity in each region and the power supply capacity remaining of stand-by power supply；

Second step, it is determined that the important level in each region.The important level in region is the highest important level of user in this region and subordinate region thereof.Being divided into three grades, one-level is the highest, and three grades minimum.For example, if region D_F8All users are general resident, and its important level is 3, if containing two grades of responsible consumers, its important level is set to 2.When it is 2, to D_F7, due to D_F7It is D_F8Higher level region, even if D_F7Middle user is entirely general user, and its significance level is also 2.I.e. D_FiImportant level be:

3rd step, calculates to meet and turns the block supply capacity of condition of power supply, if all block supply capacity and less than stand-by power supply power supply capacity remaining, illustrates that the satisfied region turning condition of power supply can turn confession；If all block supply capacity and more than stand-by power supply power supply capacity remaining, illustrate implementation section to turn confession to meeting the region turning condition of power supply.Part turns the power supply area that turns of power supply and selects according to following principle: the first important level according to region, the region that priority level is high；Secondly, for the region that important level is identical, the region that priority load capacity is big；3rd, turn the total load capacity of power supply area less than stand-by power supply power supply capacity remaining for condition with all, implement load transfer to greatest extent.

Pass through said process, it is possible to that sets up power distribution network turns power supply decision set.Thus, it is possible to obtain D_FiThe reliability index of higher level's regional effect:

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

(4) reliability index in each region calculates

The reliability index of comprehensive three parts, it is possible to obtain region D_FiPower supply reliability index:

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

Region D_FiEach load point reliability index be:

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

Wherein,For region D_FiThe failure rate of load k,For the average idle time of load k,Average time for repair of breakdowns for load k.For the indigenous fault rate of load k, it passes through region D_FiBridge piecemeal and load k piecemeal equivalent fault rate obtain,For the intrinsic average idle time of load k, it passes through region D_FiBridge piecemeal and load k piecemeal equivalent fault rate and obtain equivalent fault repair time.3) reliability index of computing system

Note region D_FiNumber of users be N_Fi, the System average interruption frequency of system is f_SAIFI, the System average interruption duration of system is T_SAIDI, the System average interruption duration of user is T_CAIDI, the power supply reliability of system is P_ASAI, then the reliability index of system is:

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

Claims (1)

1., based on a reliability assessment method for medium voltage distribution network for level regions tidal inlet, it is characterized in that:

1) by sync cap, gather the related data in distribution generalized information system, initialize the medium voltage distribution network network information and include: substation information, line information, switching information, information on load；

2) by power supply reliability information management platform, adopt the historical data of nearest 3-5, initialize wire, distribution transformer, chopper, isolation switch, these primary element unit basis information of fuse, including failure rate, average time for repair of breakdowns；

3) with chopper, isolation switch, interconnection switch for separation, power distribution network is carried out the division of ground floor region, forms parent subregion, be designated as D_Fi, in formula, Fi is parent subarea number, to belonging to same D_FiCell, have unified supplied character and turn supplied character；

4) with D_FiFor elementary cell, with chopper, isolation switch, interconnection switch for tidal inlet node, form each D_FiTidal inlet table, and determine D_FiHigher level's regional ensemble and subregion；According to tidal inlet table and the load capacity of regional, user gradation, that sets up power distribution network turns power supply decision set；

5) to each D_Fi, with fuse for separation, form D_FiTwo grades of subregions, D_FiTwo grades of subregions include two types, load point is namely from fuse to distribution transformer piecemeal and bridge piecemeal and D_FiThe module that all fuses comprise；

6) to D_Fi, by turn power supply decision set of power distribution network, it is determined that time stoppage in transit in higher level region, it turns electric power thus supplied；

7) D is calculated according to the piecemeal situation of two grades of subregions_FiInherent reliability index；Turn electric power thus supplied according to it, calculate the reliability index of higher level's regional effect；Tripping situation according to subregion entrance chopper, calculates 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, form the power supply reliability index of power distribution network.