CN103106624A - Method of building reliable improved effect relation between investment on power grid and power supply - Google Patents

Abstract

The invention discloses a method of building a reliable improved effect relation between investment on a power grid and power supply. Firstly, a relation model of feeder improvement measure investment and reliable improved effects (for reducing household weigh at blackout) including annular grid improvement, segment switch increasing, superterranean moved cables and the like is built with feeders serving as units. A cost and benefit analyzing method is used for estimating all effects of improvement measures and finally, a reliable relation model of the investment on the power grid and power supply is set up. With the method of building the reliable improved effect relation between the investment on the power grid and power supply, parameter variation of a feeder grid frame and improved household number in blackout corresponding to reliable parameter variation can be rapidly and effectively estimated, a good indicating effect can be exerted on a reliable improvement scheme on the power grid, a complicated power grid reliability estimating process is avoided, excellent reference values can be provided for arrangement of improvement of the power grid in a macroscopic mode and obtaining of the reliable level of the most proper power grid.

Description

A kind of power distribution network of establishing is invested the method for improving effect relation with power supply reliability

Technical field

The present invention relates to how improve according to power supply reliability the method for power distribution network investment, be specifically related to a kind of method that power distribution network investment and power supply reliability are improved the effect both sides relation of establishing, belong to power distribution network renovation technique field.

Background technology

Along with the growth of national economy, Chinese need for electricity constantly increases, and distribution system is as directly facing user's link in electric system, and is also direct on the impact of customer power supply quality and power supply reliability.Statistics shows, in user's power-off fault, nearly 80% is that fault by power distribution network causes.Therefore, electric power enterprise all can drop into the transformation that a large amount of funds is carried out power distribution network every year, reduces as far as possible power-off event to user's impact.Along with the sustainable growth of need for electricity, the investment for trnasforming urban land of power distribution network also will continue to enlarge and in-depth.How the huge fund input that faces the future utilizes fund and resource rationally and effectively, obtains best reliability benefit, is very problems of concerns of electric power enterprise decision maker at different levels.Many documents have carried out the discussion of reliability improvement measure and Reliability Cost-Benefit method, particularly about the analysis of reliability cost benefit, wherein comprised the relation of reliability investment between improving with reliability, providing the reliability investment is that reliability monotonically increasing function, loss of outage are the monotonic decreasing functions of reliability and judge the conclusion of electrical network optimal reliability level as principle take power supply assembly minimum.The general shortcoming of above-mentioned research is: reliability investment and reliability index are calculated based on set programme, do not provide the funtcional relationship of reliability level and investment, and how concrete object are set up the rare research of this relation.

Summary of the invention

Improve the deficiency of measure and Reliability Cost-Benefit method for existing reliability, the purpose of this invention is to provide a kind of power distribution network of establishing and invest the method for improving the effect both sides relation with power supply reliability, algorithm of the present invention is simple, can optimize distribution network reliability according to the method and improve scheme.

The present invention realizes that the technical solution of above-mentioned purpose is as follows:

A kind of power distribution network of establishing is invested the method for improving effect relation with power supply reliability, and step is as follows:

1) reliability is improved the estimation of measure effect: calculate respectively in the fault outage situation and the improve effect of various power supply reliabilities improvement measures to power supply reliability under pre-arrangement power-off condition, then various power supply reliabilities in the fault outage situation being improved measures arranges various power supply reliabilities improvement measures under power-off condition to improve the corresponding addition of effect to power supply reliability to the effect of improving of power supply reliability with pre-, namely obtain various reliabilities and improve measures and reliability and improve relation between effect, when wherein reliability is improved effect with the power failure that reduces, amount is weighed;

2) reliability is improved the cost effectiveness analysis of measure effect: respectively the unit of account investment reduce power failure the time amount, obtain returns of investment that various reliabilities improve measures than and by descending sort;

3) reliability that the foundation of power distribution network investment and power supply reliability relation: according to step 2) obtains is improved the measure returns of investment and is compared sequencing table, and integrating step 1) the reliability improvement measure that obtains and reliability are improved the relation between effect, respectively various reliabilities are improved the measure investment costs and improve the effect summation that adds up, can obtain different power distribution network investment costs and power supply reliability and improve relation between effect.

Described power supply reliability improvement measure changes three kinds of measures of cable by increase block switch, feeder terminal interpolation interconnection and pole line and consists of, and wherein increases block switch and comprises that again feeder line has interconnection and feeder line without two kinds of situations of interconnection;

The 1st) in the step in the fault outage situation various power supply reliabilities improve measures the effect of improving of power supply reliability calculated as follows:

1.1.1) the increase block switch:

When feeder line during without interconnection:

Add the time amount that affects after switch and can be divided into two parts: because of segmentation increase after the coverage of element fault reduce to bring power failure the time amount reduce and during the power failure that brings because of the switch fault that increases amount increase; After supposing to increase block switch, every line segment length of feeder line is identical, and the time amount that reduces when when this moment, feeder line had a power failure, amount does not add switch in the situation that affects of ignoring downstream adjacent segments switch fault is:

△S=λ _lL _n(T _rep.l-T _iso)K ₂N _n+λ _b(T _rep.b-T _iso)K ₂N _n

+λ _sw(T _rep.sw-T _iso)K ₂N _n

-λ _swT _isoK ₁N _n-λ _swT _rep.sw(K ₂+K ₃)N _n

When feeder line has interconnection:

Adding amount when on feeder line, the user has a power failure after switch changes and can be divided into two parts: due to the segments increase bring time amount that the roadway element failure coverage reduces to bring to reduce and during the power failure that causes when increasing switch fault amount increase, therefore amount is during the power failure that reduces after the interpolation switch:

△S=λ _lL _n(T _rep.l-T _iso)K ₂N _n+λ _b(T _rep.b-T _iso)K ₂N _n

+λ _sw(T _rep.sw-T _iso)K ₂N _n

-λ _swT _isoK ₁N _n-λ _swT _rep.sw(K ₂+K ₃)N _n

1.1.2) feeder terminal interpolation interconnection:

After feeder terminal increases interconnection, the power off time that during feeder line, amount is changed to faulted line segment downstream line segment by be reduced to repair time isolation time and switching time sum; Specific formula for calculation is:

$\mathrm{\ΔS}={\mathrm{\λ}}_l{L}_n(T_{\mathrm{rep}.l}-T_{\mathrm{iso}}-T_{\mathrm{cha}})\frac{n(n-1)}{2}{N}_n$

$+{\mathrm{\λ}}_b(T_{\mathrm{rep}.b}-T_{\mathrm{iso}}-T_{\mathrm{cha}})\frac{n(n-1)}{2}{N}_n$

$+{\mathrm{\λ}}_{\mathrm{sw}}(T_{\mathrm{rep}.\mathrm{sw}}-T_{\mathrm{iso}}-T_{\mathrm{cha}})\frac{(n-1)(n-2)}{2}{N}_n$

1.1.3) pole line changes cable:

After pole line changed cable, the feeder cable rate improved, and the outage rate that causes because of line fault reduces; During the power failure that reduces, amount is calculated as follows:

Circuit failure rate before transformation:

λ _l1=k _cl1λ _cl+(1-k _cl1)λ _ol

Circuit mean repair time before transformation:

T _rep.l1=k _cl1T _rep.cl+(1-k _cl1)T _rep.ol

Circuit failure rate after transformation:

λ _l2=k _cl2λ _cl+(1-k _cl2)λ _ol

Circuit mean repair time after transformation:

T _rep.l2=k _cl2T _rep.cl+(1-k _cl2)T _rep.ol

During feeder line, amount is changed to:

$\mathrm{\ΔS}=\left({{\mathrm{\λ}}_{l1}T}_{\mathrm{rep}.l1}{-\mathrm{\λ}}_{l2}{T}_{\mathrm{rep}.l2}\right)L_n\frac{(n+1)(n+2)}{2}{N}_n$

The 1st) in advance in the step arrange under power-off condition various power supply reliabilities to improve measures the effect of improving of power supply reliability is calculated as follows:

1.2.1) the increase block switch:

When feeder line during without interconnection:

After increasing block switch, the time amount of impact is divided into two parts: because of segmentation increase after element arrange in advance to have a power failure that time amount that coverage reduces to bring reduces and increase because of the switch that the increases time amount that brings that arranges in advance to have a power failure; After supposing to increase block switch, every line segment length of feeder line is identical, reduce when when this moment, feeder line had a power failure, amount does not add switch the time amount in the situation that ignore the impact that arranges in advance to have a power failure of downstream adjacent segments switch and be:

△S=λ′ _lL _nT′ _lK ₂N _n+λ′ _bT′ _bK ₂N _n

+λ′ _swT′ _swK ₂N _n-λ′ _swT′ _sw(K ₂+K ₃)N _n

When feeder line has interconnection:

After increasing block switch, the feeder line segments increases, from the whole piece feeder line, when on feeder line, the pre-user of arrangement has a power failure, amount changes and can be divided into two parts: due to segments increase after circuit element amount increase when arranging in advance to have a power failure the power failure that time amount that coverage reduces to bring reduces and the switch that adds causes when arranging to have a power failure in advance; Therefore increase that when having a power failure after block switch, amount is reduced to

△S=λ′ _lL _nT′ _lK ₂N _n+λ′ _bT′ _bK ₂N _n

+λ′ _swT′ _swK ₂N _n-λ′ _swT′ _sw(K ₂+K ₃)N _n

1.2.2) feeder terminal interpolation interconnection

After feeder terminal added interconnection, during power failure, amount was reduced to

$\mathrm{\ΔS}={\mathrm{\λ}}_l^{\′}{L}_n{T}_l^{\′}\frac{n(n-1)}{2}{N}_n+{\mathrm{\λ}}_b^{\′}{T}_b^{\′}\frac{n(n-1)}{2}{N}_n$

$+{\mathrm{\λ}}_{\mathrm{sw}}^{\′}(T_{\mathrm{sw}}^{\′}-T_{\mathrm{cha}})\frac{(n-1)(n-2)}{2}{N}_n$

1.2.3) pole line changes cable to improve the cable rate

After pole line changed cable, the feeder cable rate improved, and because of the outage rate reduction that line fault causes, during the power failure of minimizing, amount is calculated as follows:

The average pre-outage rate that arranges of circuit before transformation:

λ' _l1=k _cl1λ' _cl+(1-k _cl1)λ' _ol

The average pre-power off time that arranges of circuit before transformation:

T' _rep.l1=k _cl1T' _rep.cl+(1-k _cl1)T' _rep.ol

The average pre-outage rate that arranges of circuit after transformation:

λ' _l2=k _cl2λ' _cl+(1-k _cl2)λ' _ol

The average pre-power off time that arranges of circuit after transformation:

T' _l2=k _cl2T' _cl+(1-k _cl2)T' _ol

During feeder line, amount is changed to:

$\mathrm{\ΔS}=({\mathrm{\λ}}_{l1}{T}_{l1}^{\′}-{\mathrm{\λ}}_{l2}{T}_{l2}^{\′})L_n\frac{(n+1)(n+2)}{2}{N}_n$

1.3) reliability of calculating measures improves effect

With the fault outage situation with pre-arrange reliability under power-off condition to improve the effect addition can to obtain reliability corresponding to measures and improve effect.

Further, described step 2) to improve the cost effectiveness analysis concrete steps of measure effect as follows for reliability:

2.1) computed reliability improves year value that waits of measure cost of investment

$C_A=C_I\frac{{(1+i)}^{n}i}{{(1+i)}^n-1}$

In formula, C _AYear value that waits for the equipment investment expense; N is the serviceable life of equipment; C _IBe the time-adjusted investment of single device, i.e. the present worth unit price; I is rate of discount;

2.2) amount when being calculated as follows the power failure that specific investment reduces, obtain the returns of investment ratio that reliability is improved measure;

${\mathrm{IE}}_i=\frac{\mathrm{\Δ}{S}_i}{C_A}$

In formula, IE _iThe returns of investment ratio that represents i kind improvement measure, △ S _iAmount when representing power failure that i kind improvement measure reduces;

2.3) with various improvement measures according to 2.2) the returns of investment ratio that calculates carries out descending sort.

After the present invention adopts technique scheme, mainly contain following effect:

1. derive under the heterogeneous networks topological structure, the analytic model of amount when parameter of double--layer grids and reliability management level have a power failure with improvement, estimation quickly and efficiently obtains feeder line parameter of double--layer grids change and dependability parameter changes the corresponding amount when having a power failure that improves, and the reliability improvement scheme of power distribution network is had good directive function;

2. set up relation between the investment of whole power distribution network and power supply reliability from the reliability improvement of feeder line, avoided complicated evaluating reliability of distribution network process, to arrange the transformation of power distribution network from macroscopic view, obtain most suitable Distribution Network Reliability level and have good reference value;

Algorithm of the present invention is simple, and is easy to utilize, and is widely used in the foundation of power distribution network investment and power supply reliability relational model, is specially adapted to the Improvement of Engineering of Distribution Net of power supply administration.

Embodiment

the present invention is based on cost-benefit establishment power distribution network investment and power supply reliability and improve the method for effect relation, because the structure of power distribution network is comparatively complicated, at first set up the looped network transformation take feeder line as unit, increase block switch, pole line changes the relational model that the feeder line improvement measure investment such as cable and reliability are improved effect (with the power failure that reduces time amount weigh), then use the cost effectiveness analysis method that the effect of various improvement measures is assessed, finally set up power distribution network investment and power supply reliability relational model, namely obtain power distribution network investment and power supply reliability and improve the relation of effect.Concrete steps are as follows:

1) reliability is improved the estimation of measure effect: calculate respectively in the fault outage situation and the improve effect of various power supply reliabilities improvement measures to power supply reliability under pre-arrangement power-off condition, then various power supply reliabilities in the fault outage situation are improved measures to power supply reliability improve effect with pre-arrange various power supply reliabilities under power-off condition improve measures to power supply reliability improve the corresponding addition of effect, namely obtain various reliabilities improvement measures and reliability and improve relation between effect;

The power supply reliability improvement measure of the present invention's research is mainly increases block switch, feeder terminal adds interconnection and pole line changes three kinds, cable, wherein increases block switch and comprises that again feeder line has interconnection and feeder line without two kinds of situations of interconnection;

1.1) various power supply reliabilities are improved measures and to the effect computing method of improving of power supply reliability are in the fault outage situation:

1.1.1) the increase block switch:

When feeder line during without interconnection:

After adding switch, former not sectionalized line is divided into two sections, from the whole piece feeder line, the time amount of impact can be divided into two parts: because of segmentation increase after the coverage of element fault reduce to bring power failure the time amount reduce and during the power failure that brings because of the switch fault that increases amount increase.After supposing to add switch, every line segment length of feeder line is identical, and the time amount that reduces when when this moment, feeder line had a power failure, amount does not add switch is (ignoring the impact of downstream adjacent segments switch fault):

△S=λ _lL _n(T _rep.l-T _iso)K ₂N _n+λ _b(T _rep.b-T _iso)K ₂N _n

+λ _sw(T _rep.sw-T _iso)K ₂N _n

-λ _swT _isoK ₁N _n-λ _swT _rep.sw(K ₂+K ₃)N _n

When feeder line has interconnection:

After adding switch, the feeder line segments increases, from the whole piece feeder line, when on feeder line, the user has a power failure, amount changes and can be divided into two parts: because the segments increase brings time amount that the roadway element failure coverage reduces to bring to reduce and amount increase during the power failure that causes when increasing switch fault.Therefore when adding power failure less after switch, amount is:

△S=λ _lL _n(T _rep.l-T _iso)K ₂N _n+λ _b(T _rep.b-T _iso)K ₂N _n

+λ _sw(T _rep.sw-T _iso)K ₂N _n

-λ _swT _isoK ₁N _n-λ _swT _rep.sw(K ₂+K ₃)N _n

1.1.2) looped network transformation (feeder terminal interpolation interconnection):

After feeder terminal increases interconnection, the power off time that during feeder line, amount is changed to faulted line segment downstream line segment by be reduced to repair time isolation time and switching time sum; Specific formula for calculation is:

$\mathrm{\ΔS}={\mathrm{\λ}}_l{L}_n(T_{\mathrm{rep}.l}-T_{\mathrm{iso}}-T_{\mathrm{cha}})\frac{n(n-1)}{2}{N}_n$

$+{\mathrm{\λ}}_b(T_{\mathrm{rep}.b}-T_{\mathrm{iso}}-T_{\mathrm{cha}})\frac{n(n-1)}{2}{N}_n$

$+{\mathrm{\λ}}_{\mathrm{sw}}(T_{\mathrm{rep}.\mathrm{sw}}-T_{\mathrm{iso}}-T_{\mathrm{cha}})\frac{(n-1)(n-2)}{2}{N}_n$

1.1.3) track remodelling (pole line changes cable, improves the cable rate of feeder line):

After pole line changes cable, the feeder cable rate improves, the outage rate that causes because of line fault reduces, reducing numerical value is to be transformed into the pole line length of cable section and the failure rate difference between the pole line cable, the fault correction time of cable also changes to some extent than pole line simultaneously, so the failure rate of circuit and also variation thereupon of average time for repair of breakdowns.During the power failure that reduces, amount is calculated as follows:

Circuit failure rate before transformation:

λ _l1=k _cl1λ _cl+(1-k _cl1)λ _ol

Circuit mean repair time before transformation:

T _rep.l1=k _cl1T _rep.cl+(1-k _cl1)T _rep.ol

Circuit failure rate after transformation:

λ _l2=k _cl2λ _cl+(1-k _cl2)λ _ol

Circuit mean repair time after transformation:

T _rep.l2=k _cl2T _rep.cl+(1-k _cl2)T _rep.ol

During feeder line, amount is changed to:

$\mathrm{\ΔS}=\left({{\mathrm{\λ}}_{l1}T}_{\mathrm{rep}.l1}{-\mathrm{\λ}}_{l2}{T}_{\mathrm{rep}.l2}\right)L_n\frac{(n+1)(n+2)}{2}{N}_n$

1.2) arrange in advance under power-off condition various power supply reliabilities to improve the measure effect computing method to be:

Pre-arrangement has a power failure and compares with the fault outage situation, and power off time need not to consider power failure isolation time and switching over time, and power off time is pre-arrangement power off time.

1.2.1) the increase block switch:

When feeder line during without interconnection:

After adding switch, originally sectionalized line was not divided into two sections, from the whole piece feeder line, the time amount of impact can be divided into two parts: because of segmentation increase after element arrange in advance to have a power failure that time amount that coverage reduces to bring reduces and increase because of the switch that the increases time amount that brings that arranges in advance to have a power failure.After supposing to add switch, every line segment length of feeder line is identical, and the time amount that reduces when when this moment, feeder line had a power failure, amount does not add switch is (ignore downstream adjacent segments switch and arrange in advance the impact that has a power failure):

△S=λ′ _lL _nT′ _lK ₂N _n+λ′ _bT′ _bK ₂N _n

+λ′ _swT′ _swK ₂N _n-λ′ _swT′ _sw(K ₂+K ₃)N _n

When feeder line has interconnection:

After adding switch, the feeder line segments increases, from the whole piece feeder line, when on feeder line, the pre-user of arrangement has a power failure, amount changes and can be divided into two parts: due to segments increase after circuit element amount increase when arranging in advance to have a power failure the power failure that time amount that coverage reduces to bring reduces and the switch that adds causes when arranging to have a power failure in advance.Therefore add that when having a power failure after switch, amount reduces

△S=λ′ _lL _nT′ _lK ₂N _n+λ′ _bT′ _bK ₂N _n

+λ′ _swT′ _swK ₂N _n-λ′ _swT′ _sw(K ₂+K ₃)N _n

1.2.2) looped network transformation (feeder terminal interpolation interconnection)

After increasing interconnection, during feeder line, amount is changed to pre-arrangement power failure line segment downstream line segment and arranges the time in advance and be reduced to 0.Therefore add that when having a power failure after interconnection, amount is reduced to:

$\mathrm{\ΔS}={\mathrm{\λ}}_l^{\′}{L}_n{T}_l^{\′}\frac{n(n-1)}{2}{N}_n+{\mathrm{\λ}}_b^{\′}{T}_b^{\′}\frac{n(n-1)}{2}{N}_n$

$+{\mathrm{\λ}}_{\mathrm{sw}}^{\′}(T_{\mathrm{sw}}^{\′}-T_{\mathrm{cha}})\frac{(n-1)(n-2)}{2}{N}_n$

1.2.3) pole line changes cable to improve the cable rate

After pole line changes cable, the feeder cable rate improves, the outage rate that causes because of line fault reduces, therefore arrange in advance outage rate also therefore to reduce, reducing numerical value is to be transformed into the pole line length of cable section and the pre-arrangement outage rate difference between the pole line cable, the pre-arrangement power off time of cable also changes to some extent than pole line simultaneously, so average pre-outage rate and the average pre-power off time that arranges of arranging of circuit also changes thereupon.During the power failure that reduces, amount is calculated as follows:

The average pre-outage rate that arranges of circuit before transformation:

λ' _l1=k _cl1λ' _cl+(1-k _cl1)λ' _ol

The average pre-power off time that arranges of circuit before transformation:

T' _rep.l1=k _cl1T' _rep.cl+(1-k _cl1)T' _rep.ol

The average pre-outage rate that arranges of circuit after transformation:

λ' _l2=k _cl2λ' _cl+(1-k _cl2)λ' _ol

The average pre-power off time that arranges of circuit after transformation:

T' _l2=k _cl2T' _cl+(1-k _cl2)T' _ol

During feeder line, amount is changed to:

$\mathrm{\ΔS}=({\mathrm{\λ}}_{l1}{T}_{l1}^{\′}-{\mathrm{\λ}}_{l2}{T}_{l2}^{\′})L_n\frac{(n+1)(n+2)}{2}{N}_n$

1.3) reliability of calculating measures improves effect

With the fault outage situation with pre-arrange reliability under power-off condition to improve the effect addition can to obtain reliability corresponding to measures and improve effect;

2) reliability is improved the cost effectiveness analysis of measure effect:

2.1) computed reliability improves year value that waits of measure cost of investment

$C_A=C_I\frac{{(1+i)}^{n}i}{{(1+i)}^n-1}$

In formula, C _AYear value that waits for the equipment investment expense; N is the serviceable life of equipment; C _IBe the time-adjusted investment of single device, i.e. the present worth unit price; I is rate of discount;

2.2) amount when being calculated as follows the power failure that specific investment reduces, obtain the returns of investment ratio that reliability is improved measure;

${\mathrm{IE}}_i=\frac{\mathrm{\Δ}{S}_i}{C_A}$

In formula, IE _iThe returns of investment ratio that represents i kind improvement measure, △ S _iAmount when representing power failure that i kind improvement measure reduces;

2.3) with various improvement measures according to 2.2) the returns of investment ratio that calculates carries out descending sort.

3) reliability that the foundation of power distribution network investment and power supply reliability relation: according to step 2) obtains is improved the measure returns of investment and is compared sequencing table, and integrating step 1) the reliability improvement measure that obtains and reliability are improved the relation between effect, respectively various reliabilities are improved the measure investment costs and improve the effect summation that adds up, can obtain different power distribution network investment costs and power supply reliability and improve relation between effect.

Following table is that reliability is improved parameter and the implication thereof of using in the measure effect estimation.

The feeder line overall length	L	The circuit failure rate	λ l
				The total number of users of feeder line	N	The pole line failure rate	λ ol
The feeder line segments	n	The cable fault rate	λ cl
				Average every section line length	L n	Circuit mean repair time	T rep.l
Average every section line user number	N n	Pole line repair time	T rep.ol
				Feeder cable rate before and after transformation	k cl1,k cl2	Cable repair time	T rep.cl
The switchgear failure rate	λ sw	The average pre-outage rate that arranges of circuit	λ' l
				Switchgear repair time	T rep.sw	Pole line arranges outage rate in advance	λ' ol
Disconnector positioning time	T iso	Cable arranges outage rate in advance	λ' cl
				The blocked operation time	T cha	The average pre-power off time that arranges of circuit	T' rep.l
Branch line equivalent fault rate	λ b	Pole line arranges power off time in advance	T' ol
				Branch line equivalence repair time	T rep.b	Cable arranges power off time in advance	T' .cl
The load number	K1，K2，K3	?	?

Wherein:

K1 represents that the previous disconnector that increases the disconnector section counts to the load between isolating switch;

K2 represents to increase the disconnector section and counts to the load between the previous disconnector of this section;

During without interconnection, K3 represents to increase switch segments to the number of users of feeder terminal when feeder line;

When feeder line had interconnection, K3 represented to increase switch segments to the number of users between the adjacent switch of downstream;

Average every section line length: L _n=L/n

Average every section line user number: N _n=N/n

Circuit failure rate: λ _l=k _clλ _cl+ (1-k _cl) λ _ol

Circuit mean repair time: T _Rep.l=k _clT _Rep.cl+ (1-k _cl) T _Rep.ol

Average pre-outage rate: the λ ' that arranges of circuit _l=k _clλ ' _cl+ (1-k _cl) λ ' _ol

Average pre-power off time: the T' that arranges of circuit _Rep.l=k _clT' _Rep.cl+ (1-k _cl) T' _Rep.ol

Power distribution network below in conjunction with the somewhere illustrates performing step of the present invention, understands the present invention with further help.

This area comprises 24 feeder lines altogether, and the essential information of feeder line is as shown in the table.

This area's power distribution network investment is as follows with power supply reliability relational model method for building up concrete steps:

1) reliability is improved the estimation of measure effect

Feeder line 1 take this area's power distribution network improves the estimation process of measure effect as the example reliability, the evaluation method of other feeder lines by that analogy.

The value of every dependability parameter is as follows

Dependability parameter

Value

Dependability parameter

Value

Pole line failure rate λ ol	0.0668	The blocked operation time T cha	0.1
				Pole line T repair time rep.ol	2.93	Pole line arranges outage rate λ ' in advance ol	0.0747
Cable fault rate λ cl	0.0259	Pole line arranges power off time T' in advance ol	2.6189
				Cable T repair time rep.cl	4.72	Cable arranges outage rate λ ' in advance cl	0.0401
Branch line equivalent fault rate λ b	0.016	Cable arranges power off time T' in advance .cl	3.0541
				Branch line equivalence T repair time rep.b	2.06	The pre-outage rate λ ' that arranges of branch line equivalence b	0.011
Switchgear failure rate λ sw	0.0053	The pre-power off time T' that arranges of branch line equivalence .b	2.1345
				Switchgear fault correction time T rep.sw	2.19	Switchgear arranges outage rate λ ' in advance sw	0.0058
Disconnector T positioning time iso	0.5	Switch arranges power off time T' in advance .sw	1.9763

Wherein:

Average every section line length:

L _n=L/n=7.18/8=0.898

Average every section line user number:

N _n=N/n=28/8=3.5

The line cord rate:

k _cl=5.722/7.18=0.797

The circuit failure rate:

λ _l=k _clλ _cl+(1-k _cl)λ _ol=0.797×0.0259+(1-0.797)×0.0668=0.034

Circuit mean repair time: T _Rep.l=k _clT _Rep.cl+ (1-k _cl) T _Rep.ol=0.797 * 4.72+ (1-0.797) * 2.93=4.357

Average pre-outage rate: the λ ' that arranges of circuit _l=k _clλ ' _cl+ (1-k _cl) λ ' _ol=0.797 * 0.0401+ (1-0.797) * 0.0747=0.047

Average pre-power off time: the T' that arranges of circuit _l=k _clT' _cl+ (1-k _cl) T' _ol=0.797 * 3.0541+ (1-0.797) * 2.6189=2.966

The previous disconnector that increases the disconnector section is counted to the load between isolating switch:

K1=10

Increasing the disconnector section counts to the load between the previous disconnector of this section

K2=4

Increasing the disconnector section counts to the load of line end

K3=4

1.1) reliability calculated in the fault outage situation improves measure effect

1.1.1) when increasing the power failure that reduces after block switch, amount is:

△S=λ _lL _n(T _rep.l-T _iso)K ₂N _n+λ _b(×T _rep.b-T _iso)K ₂N _n

+λ _sw(T _rep.sw-T _iso)K ₂N _n

-λ _swT _isoK ₁N _n-λ _swT _rep.sw(K ₂+K ₃)N _n

=0.034×0.898×(4.357-0.5)×4×3.5+0.016×(2.06-0.5)×4×3.5

+0.0053×(2.19-0.5)×4×3.5

-0.0053×0.5×10×3.5-0.0053×2.19×(4+4)×3.5

=1.323

1.1.2) looped network transformation (feeder terminal interpolation interconnection)

Due to the existing interconnection of this feeder line, need not to carry out the looped network transformation

1.1.3) amount is calculated as follows during the power failure that reduces after track remodelling (the cable rate of feeder line is improved 20%):

Circuit failure rate before transformation:

λ _l1=k _cl1λ _cl+(1-k _cl1)λ _ol=0.797×0.0259+(1-0.797)×0.0668=0.034

Circuit mean repair time before transformation:

T _rep.l1=k _cl1T _rep.cl+(1-k _cl1)T _rep.ol=0.797×4.72+(1-0.797)×2.93=4.357

Circuit failure rate after transformation:

λ _l2=k _cl2λ _cl+(1-k _cl2)λ _ol=0.997×0.0259+(1-0.997)×0.0668=0.026

Circuit mean repair time after transformation:

T _rep.l2=k _cl2T _rep.cl+(1-k _cl2)T _rep.ol=0.997×4.72+(1-0.997)×2.93=4.715

During feeder line, amount is changed to:

$\mathrm{\ΔS}=\left({{\mathrm{\λ}}_{l1}T}_{\mathrm{rep}.l1}{-\mathrm{\λ}}_{l2}{T}_{\mathrm{rep}.l2}\right)L_n\frac{(n+1)(n+2)}{2}{N}_n$

$=(0.034\×4.357-0.026\×4.715)\×0.898\×\frac{9\×10}{2}\×3.5$

$=3.720$

1.2) calculate and to arrange the reliability under power-off condition to improve measure effect in advance

1.2.1) when increasing the power failure that reduces after block switch, amount is:

△S=λ′ _lL _nT′ _lK ₂N _n+λ′ _bT′ _bK ₂N _n

+λ′ _swT′ _swK ₂N _n-λ′ _swT′ _sw(K ₂+K ₃)N _n

=0.047×0.898×4×3.5+0.011×2.1345×4×3.5

+0.0058×1.9763×4×3.5-0.0058×1.9763×(4+4)×3.5

=1.922

1.2.2) looped network transformation (feeder terminal interpolation interconnection)

Due to the existing interconnection of this feeder line, need not to carry out the looped network transformation

1.2.3) amount is calculated as follows during the power failure that reduces after track remodelling (the cable rate of feeder line is improved 20%):

The average pre-outage rate that arranges of circuit before transformation:

λ′ _l1=k _cl1λ' _cl+(1-k _cl1)λ' _ol=0.797×0.0401+(1-0.797)×0.0747=0.047

The average pre-power off time that arranges of circuit before transformation:

T' _l1=k _cl1T' _cl+(1-k _cl1)T' _ol=0.797×3.0541+(1-0.797)×2.6189=2.996

The average pre-outage rate that arranges of circuit after transformation:

λ' _l2=k _cl2λ' _cl+(1-k _cl2)λ' _ol=0.997×0.0401+(1-0.997)×0.0747=0.040

The average pre-power off time that arranges of circuit after transformation:

T' _rep.l2=k _cl2T' _cl+(1-k _cl2)T' _ol=0.997×3.0541+(1-0.997)×2.6189=3.053

During feeder line, amount is changed to:

$\mathrm{\ΔS}=({\mathrm{\λ}}_{l1}{T}_{l1}^{\′}-{\mathrm{\λ}}_{l2}{T}_{l2}^{\′})L_n\frac{(n+1)(n+2)}{2}{N}_n$

$=(0.047\×2.996-0.040\×3.053)\×7.18\×\frac{(8+1)(8+2)}{2}\×3.5$

$=2.406$

1.3) reliability of calculating measures improves effect

After feeder line 1 increased block switch, during the power failure of minimizing, amount was: △ S ₁=1.323+1.992=3.315

The cable rate of feeder line 1 is improved 20%, and during less power failure, amount is: △ S ₂=3.720+2.406=6.126

Amount in the time of in like manner can calculating the power failure that the reliability improvement measure of other feeder lines of this area reduces.

2) reliability is improved the cost effectiveness analysis of measure effect

According to the equipment price of this area's reality and the average price situation of engineering construction, reliability is improved the unit price of the medium voltage distribution network equipment such as block switch on the related 10kV electric pressure YJV22-300 cable of measure, JKLGYJ-240 aerial insulated wire, post, and is as shown in the table:

Wherein, rate of discount i gets 9%, and operation and maintenance cost percentage H is 5%

2.1) calculate being worth in the year of waiting of feeder line 1 reliability improvement measure cost of investment

2.1.1) the increase block switch

$C_{A1}=C_{I1}\frac{{(1+i)}^{n}i}{{(1+i)}^n-1}=5\frac{{(1+0.09)}^{15}\×0.09}{{(1+0.09)}^{15}-1}=0.62$

2.1.2) cable rate raising 20%

$C_{A2}=C_{I2}\frac{{(1+i)}^{n}i}{{(1+i)}^n-1}=7.18\×20\%\×94\×\frac{{(1+0.09)}^{20}\×0.09}{{(1+0.09)}^{20}-1}=14.787$

2.2) calculate returns of investment that feeder line 1 reliability improves measure than (be specific investment reduce power failure the time amount)

2.2.1) the increase block switch

${\mathrm{IE}}_1=\frac{\mathrm{\Δ}{S}_1}{C_{A1}}=\frac{3.315}{0.62}=5.347$

2.2.2) cable rate raising 20%

${\mathrm{IE}}_2=\frac{\mathrm{\Δ}{S}_2}{C_{A2}}=\frac{6.126}{14.787}=0.414$

2.3) according to step 2.2) calculate the returns of investment ratio of the reliability improvement measure of other feeder lines, and carry out descending sort according to the returns of investment ratio;

3) foundation of power distribution network investment and power supply reliability relation

According to step 2) reliability that obtains improve measure returns of investment than sequencing table, respectively to reliability improvement measure investment with improve the effect summation that adds up, calculate reliability corresponding to different investment costs and improve effect.

The inventive method is applied in somewhere power distribution network investment and the foundation of power supply reliability relational model.Use power distribution network investment cost that above-mentioned model calculates and corresponding reliability to improve effect as shown in the table:

From the above results as can be known, utilization this method can be set up the relation between power distribution network investment and power supply reliability easily; Do not need to set up complicated Algorithm for Solving, be convenient to the engineering staff and learn to use, and versatility is better, can draw intuitively the reliability level under different power distribution networks investments, planning, operation and the transformation etc. of power distribution network are had certain reference value.

Explanation is at last, above embodiment is only unrestricted in order to technical scheme of the present invention to be described, although with reference to preferred embodiment, the present invention is had been described in detail, those of ordinary skill in the art is to be understood that, can modify or be equal to replacement technical scheme of the present invention, and not breaking away from aim and the scope of technical solution of the present invention, it all should be encompassed in the middle of claim scope of the present invention.

Claims (3)

1. establish the method that power distribution network investment and power supply reliability are improved effect relation for one kind, it is characterized in that: step is as follows:

1) reliability is improved the estimation of measure effect: calculate respectively in the fault outage situation and the improve effect of various power supply reliabilities improvement measures to power supply reliability under pre-arrangement power-off condition, then various power supply reliabilities in the fault outage situation being improved measures arranges various power supply reliabilities improvement measures under power-off condition to improve the corresponding addition of effect to power supply reliability to the effect of improving of power supply reliability with pre-, namely obtain various reliabilities and improve measures and reliability and improve relation between effect, when wherein reliability is improved effect with the power failure that reduces, amount is weighed;

2) reliability is improved the cost effectiveness analysis of measure effect: respectively the unit of account investment reduce power failure the time amount, obtain returns of investment that various reliabilities improve measures than and by descending sort;

3) reliability that the foundation of power distribution network investment and power supply reliability relation: according to step 2) obtains is improved the measure returns of investment and is compared sequencing table, and integrating step 1) the reliability improvement measure that obtains and reliability are improved the relation between effect, respectively various reliabilities are improved the measure investment costs and improve the effect summation that adds up, can obtain different power distribution network investment costs and power supply reliability and improve relation between effect.

2. establishment power distribution network investment according to claim 1 and power supply reliability are improved the method for effect relation, it is characterized in that: described power supply reliability improvement measure changes three kinds of measures of cable by increase block switch, feeder terminal interpolation interconnection and pole line and consists of, and wherein increases block switch and comprises that again feeder line has interconnection and feeder line without two kinds of situations of interconnection;

The 1st) in the step in the fault outage situation various power supply reliabilities improve measures the effect of improving of power supply reliability calculated as follows:

1.1.1) the increase block switch:

When feeder line during without interconnection:

Add the time amount that affects after switch and can be divided into two parts: because of segmentation increase after the coverage of element fault reduce to bring power failure the time amount reduce and during the power failure that brings because of the switch fault that increases amount increase; After supposing to increase block switch, every line segment length of feeder line is identical, and the time amount that reduces when when this moment, feeder line had a power failure, amount does not add switch in the situation that affects of ignoring downstream adjacent segments switch fault is:

△S=λ _lL _n(T _rep.l-T _iso)K ₂N _n+λ _b(T _rep.b-T _iso)K ₂N _n

+λ _sw(T _rep.sw-T _iso)K ₂N _n

-λ _swT _isoK ₁N _n-λ _swT _rep.sw(K ₂+K ₃)N _n

When feeder line has interconnection:

Adding amount when on feeder line, the user has a power failure after switch changes and can be divided into two parts: due to the segments increase bring time amount that the roadway element failure coverage reduces to bring to reduce and during the power failure that causes when increasing switch fault amount increase, therefore amount is during the power failure that reduces after the interpolation switch:

△S=λ _lL _n(T _rep.l-T _iso)K ₂N _n+λ _b(T _rep.b-T _iso)K ₂N _n

+λ _sw(T _rep.sw-T _iso)K ₂N _n

-λ _swT _isoK ₁N _n-λ _swT _rep.sw(K ₂+K ₃)N _n

1.1.2) feeder terminal interpolation interconnection:

After feeder terminal increases interconnection, the power off time that during feeder line, amount is changed to faulted line segment downstream line segment by be reduced to repair time isolation time and switching time sum; Specific formula for calculation is:

$\mathrm{\ΔS}={\mathrm{\λ}}_l{L}_n(T_{\mathrm{rep}.l}-T_{\mathrm{iso}}-T_{\mathrm{cha}})\frac{n(n-1)}{2}{N}_n$

$+{\mathrm{\λ}}_b(T_{\mathrm{rep}.b}-T_{\mathrm{iso}}-T_{\mathrm{cha}})\frac{n(n-1)}{2}{N}_n$

$+{\mathrm{\λ}}_{\mathrm{sw}}(T_{\mathrm{rep}.\mathrm{sw}}-T_{\mathrm{iso}}-T_{\mathrm{cha}})\frac{(n-1)(n-2)}{2}{N}_n$

1.1.3) pole line changes cable:

After pole line changed cable, the feeder cable rate improved, and the outage rate that causes because of line fault reduces; During the power failure that reduces, amount is calculated as follows:

Circuit failure rate before transformation:

λ _l1=k _cl1λ _cl+(1-k _cl1)λ _ol

Circuit mean repair time before transformation:

T _rep.l1=k _cl1T _rep.cl+(1-k _cl1)T _rep.ol

Circuit failure rate after transformation:

λ _l2=k _cl2λ _cl+(1-k _cl2)λ _ol

Circuit mean repair time after transformation:

T _rep.l2=k _cl2T _rep.cl+(1-k _cl2)T _rep.ol

During feeder line, amount is changed to:

$\mathrm{\ΔS}=\left({{\mathrm{\λ}}_{l1}T}_{\mathrm{rep}.l1}{-\mathrm{\λ}}_{l2}{T}_{\mathrm{rep}.l2}\right)L_n\frac{(n+1)(n+2)}{2}{N}_n$

The 1st) in advance in the step arrange under power-off condition various power supply reliabilities to improve measures the effect of improving of power supply reliability is calculated as follows:

1.2.1) the increase block switch:

When feeder line during without interconnection:

After increasing block switch, the time amount of impact is divided into two parts: because of segmentation increase after element arrange in advance to have a power failure that time amount that coverage reduces to bring reduces and increase because of the switch that the increases time amount that brings that arranges in advance to have a power failure; After supposing to increase block switch, every line segment length of feeder line is identical, reduce when when this moment, feeder line had a power failure, amount does not add switch the time amount in the situation that ignore the impact that arranges in advance to have a power failure of downstream adjacent segments switch and be:

△S=λ′ _lL _nT′ _lK ₂N _n+λ′ _bT′ _bK ₂N _n

+λ′ _swT′ _swK ₂N _n-λ′ _swT′ _sw(K ₂+K ₃)N _n

When feeder line has interconnection:

After increasing block switch, the feeder line segments increases, from the whole piece feeder line, when on feeder line, the pre-user of arrangement has a power failure, amount changes and can be divided into two parts: due to segments increase after circuit element amount increase when arranging in advance to have a power failure the power failure that time amount that coverage reduces to bring reduces and the switch that adds causes when arranging to have a power failure in advance; Therefore increase that when having a power failure after block switch, amount is reduced to

△S=λ′ _lL _nT′ _lK ₂N _n+λ′ _lT′ _bK ₂N _n

+λ′ _swT′ _swK ₂N _n-λ′ _swT′ _sw(K ₂+K ₃)N _n

1.2.2) feeder terminal interpolation interconnection

After feeder terminal added interconnection, during power failure, amount was reduced to

$\mathrm{\ΔS}={\mathrm{\λ}}_l^{\′}{L}_n{T}_l^{\′}\frac{n(n-1)}{2}{N}_n+{\mathrm{\λ}}_b^{\′}{T}_b^{\′}\frac{n(n-1)}{2}{N}_n$

$+{\mathrm{\λ}}_{\mathrm{sw}}^{\′}(T_{\mathrm{sw}}^{\′}-T_{\mathrm{cha}})\frac{(n-1)(n-2)}{2}{N}_n$

1.2.3) pole line changes cable to improve the cable rate

After pole line changed cable, the feeder cable rate improved, and because of the outage rate reduction that line fault causes, during the power failure of minimizing, amount is calculated as follows:

The average pre-outage rate that arranges of circuit before transformation:

λ' _l1=k _cl1λ' _cl+(1-k _cl1)λ' _ol

The average pre-power off time that arranges of circuit before transformation:

T' _rep.l1=k _cl1T' _rep.cl+(1-k _cl1)T' _rep.ol

The average pre-outage rate that arranges of circuit after transformation:

λ' _l2=k _cl2λ' _cl+(1-k _cl2)λ' _ol

The average pre-power off time that arranges of circuit after transformation:

T' _l2=k _cl2T' _cl+(1-k _cl2)T' _ol

During feeder line, amount is changed to:

$\mathrm{\ΔS}=({\mathrm{\λ}}_{l1}{T}_{l1}^{\′}-{\mathrm{\λ}}_{l2}{T}_{l2}^{\′})L_n\frac{(n+1)(n+2)}{2}{N}_n$

1.3) reliability of calculating measures improves effect

With the fault outage situation with pre-arrange reliability under power-off condition to improve the effect addition can to obtain reliability corresponding to measures and improve effect.

3. establishment power distribution network according to claim 1 and 2 investment and power supply reliability are improved the method for effect relation, it is characterized in that: described step 2) to improve the cost effectiveness analysis concrete steps of measure effect as follows for reliability:

2.1) computed reliability improves year value that waits of measure cost of investment

$C_A=C_I\frac{{(1+i)}^{n}i}{{(1+i)}^n-1}$

In formula, C _AYear value that waits for the equipment investment expense; N is the serviceable life of equipment; C _IBe the time-adjusted investment of single device, i.e. the present worth unit price; I is rate of discount;

2.2) amount when being calculated as follows the power failure that specific investment reduces, obtain the returns of investment ratio that reliability is improved measure;

${\mathrm{IE}}_i=\frac{\mathrm{\Δ}{S}_i}{C_A}$

In formula, IE _iThe returns of investment ratio that represents i kind improvement measure, △ S _iAmount when representing power failure that i kind improvement measure reduces;

2.3) with various improvement measures according to 2.2) the returns of investment ratio that calculates carries out descending sort.