CN105512807A - Network health index assessment method for power distribution network - Google Patents

Abstract

The invention relates to a network health index assessment method for a power distribution network, and the method comprises the steps: (1) determining the range of a power supply region of the power distribution network; (2) determining the fault rate lambda of key equipment according to a function relation between an HI (health index) and a fault rate lambda of key equipment of the power distribution network; (3) simplifying the power distribution network; (4) determining the power supply reliability P of the power distribution network; (5) determining the HI' of the power distribution network. The method provided by the invention employs the HI to describe the function and performance of the power distribution network on the basis of the analogy of the operation health condition of a complex power distribution network with the human health condition, builds a power distribution network health index assessment method model according to the model relation between the equipment health index and the fault rate and a fault mode and influence analysis method, can obtain the health condition and health condition change trend of the power distribution network, makes timely response to the abnormal diseases which are caused or may be caused, and guarantees that the power distribution network is healthy.

Description

A kind of power distribution network network health index appraisal procedure

Technical field

The present invention relates to power distribution network asset management technical field, be specifically related to a kind of power distribution network network health index appraisal procedure.

Background technology

The physical support of intelligent distribution network is the integrated of all new and old technology, the old and new's equipment and network, and the general level of the health of equipment and network is important foundation and the support of every other work, is that intelligent grid builds requisite foundation stone.The complicacy of Modern power distribution net, discreteness, dynamic, non-linear, multiple goal and uncertainty, propose requirements at the higher level to planning; The range of application of intelligent grid state-detection is no longer confined to the monitoring and control of electrical network equipment, repair based on condition of component and whole-life cycle fee etc., and the maintenance that will be further development of based on risk, and expand the fields such as safe operation, Optimized Operation, economical operation and good service to, support providing the application of extension for operation of power networks, integrated management etc.; The asset management of following intelligent grid is also by the category far beyond traditional electrical network asset management, and scope will significantly be expanded, comprehensive covering, manage more scientificization and intellectuality.But the development of all intelligent power distribution network technologies, the application of new technology all based on the perception to existing power distribution network, particularly to understanding and the knowledge accumulation of existing equipment and Network health.Therefore, the general level of the health of existing Distribution Network Equipment and network is grasped on comprehensive system ground, efficiently managing the lean of existing power distribution network assets is the starting point of intelligent power distribution network construction, not only can be power grid risk control and device management strategies important information is provided, and the global reliability of electric system can be ensured, reduce operation and maintenance expenses use, improve rate of return on investment, for intelligent grid builds lay a good foundation.

But the research object of existing health index is only limitted to individual equipment element, not yet expands to network, and lays particular emphasis on the equipment that extends service in the army, take residual life as main target.Current high-tension apparatus health index research is relatively accurate, ripe, controller switching equipment relative qualitative, extensive, in research method, be short of in depth theoretical research and information law mining simultaneously, model is fairly simple, constant and edge-restraint condition often depend on experience, lay particular emphasis on the result after faults itself model, single level, the HI of single cross section (static state) and fault, the method of simple quantitative analysis and simple health index evaluation index, not yet organically combine equipment health index with efficiency, planning, maintenance.

Summary of the invention

For the deficiencies in the prior art, the invention provides a kind of power distribution network network health index appraisal procedure, health status is run with on the basis of health state phase analogy at Complicated Distribution Network, health index is used to describe function and the performance characterization of power distribution network, power distribution network health index appraisal procedure model is established according to the relationship model between equipment health index and failure rate and fault modes and effect analysis method (FMEA), self health status and the variation tendency thereof of power distribution network can be drawn, to causing or contingent abnormal condition, make response early, ensure that it is in health status.

The object of the invention is to adopt following technical proposals to realize:

A kind of power distribution network network health index appraisal procedure, its improvements are, comprising:

(1) described power distribution network power supply area scope is determined;

(2) according to the health index HI of the key equipment of described power distribution network and the funtcional relationship of failure rate λ, the failure rate λ of described key equipment is determined;

(3) abbreviation is carried out to described power distribution network;

(4) the power supply reliability P of described power distribution network is determined;

(5) described power distribution network network health index HI ' is determined.

Preferably, in described step (2), determine the year failure rate p of the i-th class key equipment _i, formula is:

p _i＝n _i/N _i×100％(1)

In formula (1), n _ibe the year faulty equipment quantity of the i-th class key equipment, N _ii-th class key equipment sum;

Determine the health index HI of the i-th class key equipment _iwith failure rate λ _ifuntcional relationship, formula is:

${\mathrm{\λ}}_i=K\×e^{\frac{{\mathrm{HI}}_i-10}{{\mathrm{HI}}_i}\·C}---\left(2\right)$

In formula (2), K is scale-up factor, and C is curve coefficients.

Further, obtain described Proportional coefficient K and curve coefficients C by Inversion Calculation, formula is:

$p_i=n_i/N_i\×100\%={\Σ}_j^4\frac{N_{ij}\·K\×e^{{\mathrm{HI}}_{ij}\·C}}{N_{ij}}\×100\%---\left(3\right)$

In formula (3), p _ibe the year failure rate of the i-th class key equipment, n _ibe the year faulty equipment quantity of the i-th class key equipment, N _ii-th class key equipment sum, K is scale-up factor, and C is curve coefficients, N _ijfor the i-th class key equipment quantity that Health Category is j, HI _ijbe the mean value of the health index of the i-th class key equipment of j for Health Category.

Further, the Health Category of described i-th class key equipment is divided into level Four, comprising: work as HI _ibelong to (0,2], the Health Category of described i-th class key equipment is one-level, and health status is good, works as HI _ibelong to (2,4], the Health Category of described i-th class key equipment is secondary, and health status is normal, works as HI _ibelong to (4,7], the Health Category of described i-th class key equipment is three grades, and health status is poor, works as HI _ibelong to (7,10), the Health Category of described i-th class key equipment is level Four, and health status is serious.

Preferably, in described step (3), adopt network morals education that the impact of branch feeder on main feeder in described power distribution network is equivalent to the equivalent node branch road being connected on main feeder.

Further, the failure rate λ of the equivalent node branch road of main feeder is connected on described in _ecomputing formula be:

${\mathrm{\λ}}_e=(1-p_b)\underset{s=1}{\overset{n}{\Σ}}{\mathrm{\λ}}_s---\left(4\right)$

In formula (4), p _bfor the correct operation probability of described branch feeder head end isolating switch, n is the node element number by breaker control on described branch feeder, λ _sfor described branch feeder being subject to the rate of breakdown of the node element of breaker control.

Preferably, in described step (4), utilize fault modes and effect analysis method, Reliability Evaluation carried out to described power distribution network, comprising:

Described power distribution network is converted to the network structure be made up of the parallel-connection structure of string on main feeder, in described network structure, the power supply reliability P ' of parallel-connection structure is:

$P^{\′}=1-\underset{i=1}{\overset{x}{\Π}}(1-P_i)---\left(5\right)$

In formula (5), x is element number in described parallel-connection structure, P _ifor the failure rate of i-th key equipment or equivalent node branch road in described parallel-connection structure;

The power supply reliability P of described network structure is:

$P=\underset{j=1}{\overset{y}{\Π}}{P}_j^{\′}---\left(6\right)$

In formula (6), y is the number of parallel-connection structure in described network structure.

Preferably, in described step (5), determine described power distribution network network health index HI ', formula is:

HI′＝10/(1-lnP/C)(7)

In formula (7), P is the power supply reliability of described power distribution network, and C is curve coefficients.

Preferably, after described step (5), also comprise: the health status determining described power distribution network according to the health index HI ' of described power distribution network;

When HI ' belong to (0,2], the Health Category of described power distribution network is one-level, health status is good, when HI ' belong to (2,4], the Health Category of described power distribution network is secondary, and health status is normal, when HI ' belongs to (4,7], the Health Category of described power distribution network is three grades, and health status is poor, when HI ' belongs to (7,10), the Health Category of described power distribution network is level Four, and health status is serious.

Preferably, the key equipment of described power distribution network comprises: substation transformer, switch, overhead transmission line and cable.

Compared with immediate prior art, the beneficial effect that the present invention has:

(1) a kind of power distribution network network health index appraisal procedure provided by the invention, by health index theory is expanded to colony's equipment and distribution network from single equipment, comprehensively can weigh the general level of the health of distribution network, advanced technological means and utility can be provided for the analysis on the health status assessment of domestic and international distribution industry magnanimity colony's controller switching equipment and power distribution network.

(2) a kind of power distribution network network health index appraisal procedure provided by the invention, not only consider and statistical study is carried out to equipment actual operating state and the failure rate of electrical equipment obtained by long-term, and propose based on the failure rate under the equipment current state of health index, make result of calculation more accurate.

(3) a kind of power distribution network network health index appraisal procedure provided by the invention, on the basis of using for reference international advanced experience, the health index appraisal procedure of colony's equipment and network is established from brand-new visual angle, change reliability consideration for a long time only lay particular emphasis on single equipment at a time, single cross section (static state), result after fault and causal research, for power distribution network asset management to provide the foundation theory and technology means in the combination of Macrocosm and microcosm aspect, for intelligent power distribution network construction has established solid foundation.

(4) a kind of power distribution network network health index appraisal procedure provided by the invention, brand-new visual angle and dimension can be provided for asset management links such as distribution network planning, maintenance and operations, promote power distribution network asset management rising to from qualitative to quantitative, there is very strong engineer applied be worth, power distribution network asset management can be effectively advanced to stride forward to lean, scientific, systematization, effective lifting mains supply reliability, realizes the maximization of power distribution network benefit.

Accompanying drawing explanation

Fig. 1 is a kind of power distribution network network health index appraisal procedure process flow diagram provided by the invention;

Fig. 2 is power distribution network complex network figure in the embodiment of the present invention;

Fig. 3 is power distribution network abbreviation schematic diagram in the embodiment of the present invention;

Fig. 4 is the radial feeder network of power distribution network in the embodiment of the present invention;

Fig. 5 is the schematic network structure of parallel-connection structure composition in the embodiment of the present invention;

Fig. 6 is distribution network system structural representation in the embodiment of the present invention.

Embodiment

Below in conjunction with accompanying drawing, the specific embodiment of the present invention is described in further detail.

For making the object of the embodiment of the present invention, technical scheme and advantage clearly, below in conjunction with the accompanying drawing in the embodiment of the present invention, technical scheme in the embodiment of the present invention is clearly and completely described, obviously, described embodiment is the present invention's part embodiment, instead of whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art, not making other embodiments all obtained under creative work prerequisite, belong to the scope of protection of the invention.

The invention provides a kind of power distribution network network health index appraisal procedure, as shown in Figure 1, comprising:

(1) described power distribution network power supply area scope is determined;

(2) according to the health index HI of the key equipment of described power distribution network and the funtcional relationship of failure rate λ, the failure rate λ of described key equipment is determined;

Wherein, the key equipment of described power distribution network comprises: substation transformer, switch, overhead transmission line and cable.

(3) abbreviation is carried out to described power distribution network;

(4) the power supply reliability P of described power distribution network is determined;

(5) described power distribution network network health index HI ' is determined.

Concrete, in described step (2), determine the year failure rate p of the i-th class key equipment _i, formula is:

p _i＝n _i/N _i×100％(1)

In formula (1), n _ibe the year faulty equipment quantity of the i-th class key equipment, N _ii-th class key equipment sum;

Determine the health index HI of the i-th class key equipment _iwith failure rate λ _ifuntcional relationship, formula is:

${\mathrm{\λ}}_i=K\×e^{\frac{{\mathrm{HI}}_i-10}{{\mathrm{HI}}_i}\·C}---\left(2\right)$

In formula (2), K is scale-up factor, and C is curve coefficients.

Wherein, obtain described Proportional coefficient K and curve coefficients C by Inversion Calculation, formula is:

$p_i=n_i/N_i\×100\%={\Σ}_j^4\frac{N_{ij}\·K\×e^{{\mathrm{HI}}_{ij}\·C}}{N_{ij}}\×100\%---\left(3\right)$

In formula (3), p _ibe the year failure rate of the i-th class key equipment, n _ibe the year faulty equipment number of the i-th class key equipment, N _ii-th class key equipment sum, K is scale-up factor, and C is curve coefficients, N _ijfor the i-th class key equipment quantity that Health Category is j, HI _ijbe the mean value of the health index of the i-th class key equipment of j for Health Category.

Wherein, all kinds of key equipment its respective Proportional coefficient K corresponding and curve coefficients C.

The Health Category of described i-th class key equipment is divided into level Four, comprising: work as HI _ibelong to (0,2], the Health Category of described i-th class key equipment is one-level, and health status is good, works as HI _ibelong to (2,4], the Health Category of described i-th class key equipment is secondary, and health status is normal, works as HI _ibelong to (4,7], the Health Category of described i-th class key equipment is three grades, and health status is poor, works as HI _ibelong to (7,10), the Health Category of described i-th class key equipment is level Four, and health status is serious.

Also comprise after described step (2): step (3) carries out abbreviation to described power distribution network, concrete operations are adopt network morals education that the impact of branch feeder on main feeder in described power distribution network is equivalent to the equivalent node branch road being connected on main feeder.

Wherein, the fundamental purpose of networked examination be by the power distribution network containing labyrinth as far as possible abbreviation become containing the power distribution network of clear radial branch feeder structure.Branch feeder, containing upwards equivalence and downwards equivalence two kinds, in the process of upwards equivalence, represents the impact of the higher level's feeder line equivalent node branch road of a string in higher level's feeder line by network morals education; In the process of downward equivalence, higher level's feeder line is represented at the equivalent node branch road of subordinate's feeder line head end the impact of a subordinate's feeder line string.

In power distribution network, main feeder is the feeder line of the power supply point from distribution network, and branch feeder is the feeder line being connected to main feeder and powering to multiple load point, and due to physical cabling demand, the lower floor of branch feeder still can with a point stand feeder line;

By in the process of branch feeder Equivalent Simplification, as shown in Figure 2, Figure 3 and Figure 4, by the E in Fig. 2 ₃be equivalent to equivalent node branch road E in Fig. 3 ₃, then by the E in Fig. 3 ₂be equivalent in Fig. 4 the equivalent node branch road E being connected on main feeder ₂, complete power distribution network complex network figure, as shown in Figure 2, progressively abbreviation becomes the radial feeder network of power distribution network, as shown in Figure 4;

The described failure rate λ being connected on the equivalent node branch road of main feeder _ecomputing formula be:

${\mathrm{\λ}}_e=(1-p_b)\underset{s=1}{\overset{n}{\Σ}}{\mathrm{\λ}}_s---\left(4\right)$

In formula (4), p _bfor the correct operation probability of described branch feeder head end isolating switch, n is the node element number by breaker control on described branch feeder, λ _sfor described branch feeder being subject to the rate of breakdown of the node element of breaker control.

In addition, the power distribution network that structure is very complicated, abbreviation is also limited.The more specifying informations comprised to former network of abbreviation branch road just omit a lot, are unfavorable for accurately comprehensively holding the macroscopic view of overall performance of network; Abbreviation is improper, then can increase calculated amount again, so the appropriateness significant of abbreviation.

In described step (4), utilize fault modes and effect analysis method, Reliability Evaluation carried out to described power distribution network, comprising:

Described power distribution network is converted to the network structure be made up of the parallel-connection structure of string on main feeder, in described network structure, the power supply reliability P ' of parallel-connection structure is:

$P^{\′}=1-\underset{i=1}{\overset{x}{\Π}}(1-P_i)---\left(5\right)$

In formula (5), x is element number in described parallel-connection structure, P _ifor the failure rate of i-th key equipment or equivalent node branch road in described parallel-connection structure;

The power supply reliability P of described network structure is:

$P=\underset{j=1}{\overset{y}{\Π}}{P}_j^{\′}---\left(6\right)$

In formula (6), y is the number of parallel-connection structure in described network structure.

Such as, as shown in Figure 5, described network structure comprises 3 parallel-connection structures, and wherein, individual equipment or equivalent node branch road are also parallel-connection structures.

In described step (5), determine described power distribution network network health index HI ', formula is:

HI′＝10/(1-lnP/C)(7)

In formula (7), P is the power supply reliability of described power distribution network, and C is curve coefficients.

After described step (5), also comprise: the health status determining described power distribution network according to the health index HI ' of described power distribution network;

When HI ' belong to (0,2], the Health Category of described power distribution network is one-level, health status is good, when HI ' belong to (2,4], the Health Category of described power distribution network is secondary, and health status is normal, when HI ' belongs to (4,7], the Health Category of described power distribution network is three grades, and health status is poor, when HI ' belongs to (7,10), the Health Category of described power distribution network is level Four, and health status is serious.

Embodiment:

As shown in Figure 5, add up respectively in two times, the health index of the key equipment that feeder system is concerned about, mainly comprise: 8 station power distribution transformers, 11 cable lines and 1 isolating switch, and be divided into respective bins, add up the quantity of each equipment in each interval range again, and add up each equipment sum and each faulty equipment total and calculate each equipment year fault rate.Then according to formula (3) for the parameter K of distinct device and C, as shown in table 1;

The parameter K of each equipment of table 1 and the result of calculation of C

Now construct 5 kinds of typical cases to the health index assignment of equipment each in feeder line, and calculate accordingly result.

Case 1: contained by feeder line 4, the health index of equipment is 3;

Case 2: in feeder line 4, the health index of L32 is 5, the health index of all the other equipment is 3;

Case 3: in feeder line 4, the health index of L26 is 5, the health index of all the other equipment is 3;

Case 4: in feeder line 4, the health index of T21 is 5, the health index of all the other equipment is 3;

Case 5: consider that load point 21 is government, machine-operated user, double circuit feeding mode is adopted to it.Wherein in a loop line road, the health index of T21 is 5, and the health index of all the other equipment is 3.

Utilize the failure rate model of formula (2) key equipment, obtained the failure rate of each equipment in different case by health index, as shown in table 2:

The failure rate result of calculation of each equipment in table 2 case 1-5

In table 2, [1] is health index is the equipment L32 of 5 points and the failure rate of equipment L26; The failure rate of [2] to be health index the be equipment T21 of 5 points.

According to the failure rate of each equipment, in conjunction with the connection in series-parallel relation of network, utilize formula (6) and formula (7) that failure rate P and the health index HI ' of distribution network system can be calculated, as shown in table 3:

The failure rate P of distribution network system and health index HI ' result of calculation in table 3 case 1-5

Result of calculation is analyzed:

(1) in system, the health index of single equipment is very little for system health exponential effect;

(2) the network health index of power distribution network is always less than the most equipment health index wherein comprised, because the most structure of power distribution network is comparatively single, the malfunction and failure of arbitrary equipment all can affect its place branch road and subordinate's feeder line power supply capacity.

(3) equipment that health index is identical can be also different on the impact of network health index due to the status difference in the feeder line of place.This is because the higher grade that electrical equipment is in feeder line, the consequence that its malfunction and failure causes is also more serious.Case 1,2,3 relatively in can embody.

(4) double back wiring can promote network health performance, namely adopts the method increasing redundance to improve system power supply reliability.Case 1,4,5 relatively in can embody.

(5) health status of case 1-4 is poor, needs to take the measures such as maintenance, and the health status of case 5 is normal, normal management.

Finally should be noted that: above embodiment is only in order to illustrate that technical scheme of the present invention is not intended to limit; although with reference to above-described embodiment to invention has been detailed description; those of ordinary skill in the field are to be understood that: still can modify to the specific embodiment of the present invention or equivalent replacement; and not departing from any amendment of spirit and scope of the invention or equivalent replacement, it all should be encompassed within claims of the present invention.

Claims (10)

1. a power distribution network network health index appraisal procedure, is characterized in that, comprising:

(1) described power distribution network power supply area scope is determined;

(2) according to the health index HI of the key equipment of described power distribution network and the funtcional relationship of failure rate λ, the failure rate λ of described key equipment is determined;

(3) abbreviation is carried out to described power distribution network;

(4) the power supply reliability P of described power distribution network is determined;

(5) described power distribution network network health index HI ' is determined.

2. the method for claim 1, is characterized in that, in described step (2), determines the year failure rate p of the i-th class key equipment _i, formula is:

p _i＝n _i/N _i×100％(1)

In formula (1), n _ibe the year faulty equipment quantity of the i-th class key equipment, N _ii-th class key equipment sum;

Determine the health index HI of the i-th class key equipment _iwith failure rate λ _ifuntcional relationship, formula is:

${\mathrm{\λ}}_i=K\×e^{\frac{{\mathrm{HI}}_i-10}{{\mathrm{HI}}_i}\·C}---\left(2\right)$

In formula (2), K is scale-up factor, and C is curve coefficients.

3. method as claimed in claim 2, it is characterized in that, obtain described Proportional coefficient K and curve coefficients C by Inversion Calculation, formula is:

$p_i=n_i/N_i\×100\%={\mathrm{\Σ}}_j^4\frac{N_{ij}\·K\×e^{{\mathrm{HI}}_{ij}\·C}}{N_{ij}}\×100\%---\left(3\right)$

In formula (3), p _ibe the year failure rate of the i-th class key equipment, n _ibe the year faulty equipment quantity of the i-th class key equipment, N _ii-th class key equipment sum, K is scale-up factor, and C is curve coefficients, N _ijfor the i-th class key equipment quantity that Health Category is j, HI _ijbe the mean value of the health index of the i-th class key equipment of j for Health Category.

4. method as claimed in claim 3, it is characterized in that, the Health Category of described i-th class key equipment is divided into level Four, comprising: work as HI _ibelong to (0,2], the Health Category of described i-th class key equipment is one-level, and health status is good, works as HI _ibelong to (2,4], the Health Category of described i-th class key equipment is secondary, and health status is normal, works as HI _ibelong to (4,7], the Health Category of described i-th class key equipment is three grades, and health status is poor, works as HI _ibelong to (7,10), the Health Category of described i-th class key equipment is level Four, and health status is serious.

5. the method for claim 1, is characterized in that, in described step (3), adopts network morals education that the impact of branch feeder on main feeder in described power distribution network is equivalent to the equivalent node branch road being connected on main feeder.

6. method as claimed in claim 5, is characterized in that, described in be connected on the failure rate λ of the equivalent node branch road of main feeder _ecomputing formula be:

${\mathrm{\λ}}_e=(1-p_b)\underset{s=1}{\overset{n}{\Σ}}{\mathrm{\λ}}_s---\left(4\right)$

In formula (4), p _bfor the correct operation probability of described branch feeder head end isolating switch, n is the node element number by breaker control on described branch feeder, λ _sfor described branch feeder being subject to the rate of breakdown of the node element of breaker control.

7. the method for claim 1, is characterized in that, in described step (4), utilizes fault modes and effect analysis method, carries out Reliability Evaluation, comprising described power distribution network:

Described power distribution network is converted to the network structure be made up of the parallel-connection structure of string on main feeder, in described network structure, the power supply reliability P ' of parallel-connection structure is:

$P^{\′}=1-\underset{i=1}{\overset{x}{\Π}}(1-P_i)---\left(5\right)$

In formula (5), x is element number in described parallel-connection structure, P _ifor the failure rate of i-th key equipment or equivalent node branch road in described parallel-connection structure;

The power supply reliability P of described network structure is:

$P=\underset{j=1}{\overset{y}{\Π}}{P}_j^{\′}---\left(6\right)$

In formula (6), y is the number of parallel-connection structure in described network structure.

8. the method for claim 1, is characterized in that, in described step (5), determine described power distribution network network health index HI ', formula is:

HI′＝10/(1-lnP/C)(7)

In formula (7), P is the power supply reliability of described power distribution network, and C is curve coefficients.

9. the method for claim 1, is characterized in that, after described step (5), also comprises: the health status determining described power distribution network according to the health index HI ' of described power distribution network;

When HI ' belong to (0,2], the Health Category of described power distribution network is one-level, health status is good, when HI ' belong to (2,4], the Health Category of described power distribution network is secondary, and health status is normal, when HI ' belongs to (4,7], the Health Category of described power distribution network is three grades, and health status is poor, when HI ' belongs to (7,10), the Health Category of described power distribution network is level Four, and health status is serious.

10. the method for claim 1, is characterized in that, the key equipment of described power distribution network comprises: substation transformer, switch, overhead transmission line and cable.