CN104103019B

CN104103019B - Operation risk assessment method and assessment system of power distribution network containing distributed power supply

Info

Publication number: CN104103019B
Application number: CN201410281567.0A
Authority: CN
Inventors: 施慎行; 尚宇炜; 董新洲
Original assignee: Tsinghua University
Current assignee: Tsinghua University
Priority date: 2014-06-20
Filing date: 2014-06-20
Publication date: 2017-05-10
Anticipated expiration: 2034-06-20
Also published as: CN104103019A

Abstract

The invention provides an operation risk assessment method of a power distribution network containing a distributed power supply. The operation risk assessment method comprises the following steps: confirming a fault state set in a power distribution network; according to a preset fault probability assignment rule, calculating the generation probability of each fault in the fault state set; according to a preset computation rule, calculating a corresponding assessment index value in the fault state set when each fault happens; according to the assessment index value corresponding to each fault and the generation probability of each fault, obtaining a risk assessment index value of each fault; and according to the risk assessment index value of each fault, confirming an operation risk assessment index value of the power distribution network. Correspondingly, the invention also provides an operation risk assessment system of the power distribution network containing the distributed power supply. According to the technical scheme of the invention, different practical requirements can be met, a great quantity of operation information in the power distribution network can be integrated, extracted and analyzed, and the control of a risk level is enhanced.

Description

Power distribution network operation risk assessment method containing distributed power source and assessment system

Technical field

The present invention relates to technical field of power systems, in particular to a kind of distribution network operation containing distributed power source Methods of risk assessment and a kind of power distribution network operation risk assessment system containing distributed power source.

Background technology

Study of Risk Evaluation Analysis for Power System can be divided into Power System Planning risk assessment and power system according to its assessment feature Operation risk assessment.Power System Planning risk assessment is used for analyzing the quality of different programmes, is Power System Planning Instruction is provided with operation steady in a long-term；Electric power system operation risk assessment is then on the basis of existing electrical network, using system The information of real time execution provides assessment and early warning to the system operation risk in the current and future short time, and operation risk assessment is Jing is applied in power transmission network, achieves good actual effect.

However, compared with power transmission network, power distribution network is in network topology structure, the method for operation, number of devices and traffic control weight The aspects such as the object of point concern have difference, cause power distribution network also different from the method for the operation risk assessment of power transmission network.In recent years Come, the power distribution network scale of China is increasing, and network topology structure also becomes increasingly complex, power supply reliability of the people to power distribution network Property, the quality of power supply and service quality requirement more and more higher；In addition, power distribution network includes distributed power source, microgrid and energy storage Device etc., the power distribution situation for making power distribution network easily changes, and dispatcher is difficult to grasp input, sends active and reactive power Change so that very difficult to the adjustment of distribution circuit electric voltage control, the generation of failure may change estimated failed shorted Levels of current simultaneously affects the distribution of voltage and short circuit current so that the potential operation risk of power distribution network is greatly increased.

Accordingly, it would be desirable to a kind of new technical scheme, can adapt to it is different be actually needed, help the whole splitting or integrating of dispatcher Analysis, refine substantial amounts of operation information in power distribution network, for power distribution network safe early warning and stable operation play important guidance and make With, and while every risk assessment index is quickly given, it is ensured that the accuracy of risk assessment, strengthen the palm to risk level Control.

The content of the invention

The present invention is based on the problems referred to above, it is proposed that a kind of new technical scheme, can adapt to it is different be actually needed, Help dispatcher to integrate, analyze, substantial amounts of operation information in power distribution network refined, for the safe early warning and stable fortune of power distribution network Row plays important directive function, and while every risk assessment index is quickly given, it is ensured that the accuracy of risk assessment, Strengthen the control to risk level.

In view of this, the present invention proposes a kind of power distribution network operation risk assessment method containing distributed power source, including：Really Determine the malfunction set in power distribution network；According to default probability of malfunction assignment rule, calculate every in the malfunction set The probability that individual failure occurs；According to default computation rule, correspondence when calculating each failure generation in the malfunction set Evaluation index value, and the probability occurred according to the corresponding evaluation index value of described each failure and described each failure obtains The risk assessment desired value of each failure；The power distribution network is determined according to the risk assessment desired value of each failure Operation risk assessment desired value.

In the technical scheme, by arranging brand-new probability of malfunction assignment rule, using Fault enumeration algorithm, traversal system The imaginary fault set of system, with the operation risk desired value of failure the probability that the failure occurs is multiplied by, and quickly calculates institute faulty Risk assessment desired value, the risk assessment desired value obtained by superposition to obtain power distribution network operation risk assessment desired value, protect While having demonstrate,proved the high speed of risk assessment, the accuracy of assessment is also ensure that, widened usage range, enhanced to risk water Flat control, improves the safety coefficient of power distribution network.

In above-mentioned technical proposal, it is preferable that the default probability of malfunction assignment rule is specifically included：By the failure State set is divided into line fault collection and other fault sets, and the probability that the line fault collection occurs is set to into the first probability, The probability that described other fault sets occur is set to into the second probability, wherein, first probability and the second probability sum For 1；Arbitrary corresponding of line fault is concentrated according to corresponding first probability of the line fault collection, and the line fault The first ratio between the total length of the length of one circuit and the corresponding all circuits of the line fault collection, calculates described arbitrary The probability that line fault occurs；And according to corresponding second probability of described other fault sets, and in described other fault sets The corresponding longtime running statistical probability of arbitrary other failures every other failure corresponding with described other fault sets it is total long-term The second ratio between operating statistic probability, calculates the probability that described arbitrary other failures occur.

In the technical scheme, it is proposed that a kind of probability of malfunction assignment rule, make risk assessment index in power distribution network not The same time of running, different operation topologys are lower with stronger comparativity.For the tradition that the probability that failure occurs carries out assignment is done Method is to carry out assignment according to the chromic trouble statistics of the element, and this results in power distribution network in the different times of running, different fortune Probability of malfunction summation under row topology is different, but the network operation topological structure of power distribution network is very flexible, under not in the same time, The total failare probability of system is differed can be led to not accurately compare risk assessment index.Therefore, in the present invention, arrange and occur The probability sum of failure is always 1, that is, power distribution network can not possibly be perfectly safe under thinking any time, in addition, for different nets Network topology, is fixed value 1 by arranging total probability of malfunction sum, risk assessment index is still had under heterogeneous networks topology Comparativity, thus the trend of reflected well power distribution network operation risk.Meanwhile, match somebody with somebody in the power distribution network of China, especially city In electrical network, buried cable is just progressively replacing overhead transmission line, urban to have been realized in more than 80% buried cable coverage rate, Buried cable is affected less by conditions such as weather, and its line fault probability is relatively fixed, and with being uniformly distributed its circuit is simulated Probability of malfunction has higher accuracy.

In above-mentioned technical proposal, it is preferable that the evaluation index value includes that overall operation desired value and individual event operation refer to Scale value, wherein, the overall operation desired value includes node voltage mean value specification value, and the individual event operating index value includes node The too low more line desired value of overtension more line desired value, node voltage, line transmission overload objective value and equipment operating overload refer to Scale value.

In the technical scheme, the node voltage mean value specification in overall operation index is used to reflect whole distribution network operation During average voltage level and the degree of risk residing for power distribution network entirety.In individual event operating index, node voltage mistake Height gets over line index to be used to reflect the risk that voltage in runtime exceedes setting limit, its practical risk for embodying may cause after Electrical protective device action, or cause parts of electrical components to damage；Brownout gets over line index for reflecting electricity in runtime Force down in the risk of setting limit, the practical risk that it embodies is probably to cause protective relaying device action, subregion load It is overweight to need excision or distributed power source in island operation state etc.；Line transmission overload objective is used to reflect runtime The power of middle line transmission exceedes it can accommodate the risk of limit, and the practical risk that it embodies is probably to cause protective relaying device Action or the overload of subregion；Equipment operating overload index is used to reflect each transformer through-put power overload in power distribution network And be damaged or cause the risk of itself relay protection action.

In above-mentioned technical proposal, it is preferable that for the evaluation index value, important level is set, and according to described important Grade is that the evaluation index value arranges corresponding weighted value.

It is operation risk setup measures important level in the technical scheme, power distribution network can be made in different run times And/or under different topology structure can inspiration change the important level and respective weights of each operation risk index.Different Power distribution network due to towards terminal client it is different, even same power distribution network is likely to different pipes in the different times of running Reason target, for example, when user participates in great social activities, power distribution network can pay close attention to the reliability to the customer power supply, separately Outward, the operation conditions of even power distribution network is identical, due to different externally and/or internally factors, can still result in power distribution network With different degrees of risk.Therefore, the important level of operation risk index is flexibly set, power distribution network actual motion is adapted to Needs, increased power distribution network assessment practicality.

In above-mentioned technical proposal, it is preferable that by every operation risk in power distribution network described in default disposal methods The weighted value of index；

The default processing method includes：According to the first preset formula and the second preset formula to every operation risk The weighted value of index is fitted, wherein：First preset formula is：

Second preset formula is：

Wherein, when operation risk index is node voltage index, a_maxFor upper critical value, a of the node voltage_minFor The lower critical value of the node voltage, q (x)_Rise、q(x)_DropFor the weighted value of the node voltage, x is node voltage value, and k is tune Integral coefficient, A_Rise、A_Drop、B_Rise、B_DropSetting value is, wherein, A_Rise、A_DropFor magnification function value, make functional value interval in [0.005,1] It is interior, B_Rise、B_DropFor setting tolerance size；

When operation risk index is that node voltage is too high gets over line index, a_maxFor the upper critical value of the node voltage, q (x)_RiseFor the weighted value of the node voltage, x is node voltage value, and k is regulation coefficient, A_Rise、B_RiseSetting value is, wherein, A_Rise For magnification function value, make functional value interval interior in [0.005,1], B_RiseFor setting tolerance size；

When operation risk index is that node voltage is too low gets over line index, a_minFor the lower critical value of the node voltage, q (x)_DropFor the weighted value of the node voltage, x is node voltage value, and k is regulation coefficient, A_Drop、B_DropSetting value is, wherein, A_Drop For magnification function value, make functional value interval interior in [0.005,1], B_DropFor setting tolerance size；

When operation risk index is line transmission overload objective, a_maxFor upper critical value, a of line transmission power_minFor The lower critical value of the line transmission power, q (x)_Rise、q(x)_DropFor the weighted value of the line transmission power, x is line transmission Performance number, k is regulation coefficient, A_Rise、A_Drop、B_Rise、B_DropSetting value is, wherein, A_Rise、A_DropFor magnification function value, functional value is set to exist [0.005,1] in interval, B_Rise、B_DropFor setting tolerance size；

When operation risk index is equipment operating overload index, a_maxFor upper critical value, a that equipment runs power_minFor The equipment runs the lower critical value of power, q (x)_Rise、q(x)_DropFor the weighted value that the equipment runs power, x is that equipment runs Performance number, k is regulation coefficient, A_Rise、A_Drop、B_Rise、B_DropSetting value is, wherein, A_Rise、A_DropFor magnification function value, functional value is set to exist [0.005,1] in interval, B_Rise、B_DropFor setting tolerance size.

In the technical scheme, by taking the too high more line index of node voltage as an example, the node that final choice goes out gets over voltage limit is It is compared what is obtained with the critical value of setting, when certain node voltage is close and less than critical value, traditional method is typically sentenced The fixed voltage is normal, line index is got over to overtension and is not contributed, though but the node voltage is less than critical point, positioned at critical Near point, the voltage is although slightly lower with respect to the contribution weight that other node voltages get over line index to final overtension, but really Real also to have a small amount of contribution, simply casting out it can reduce computational accuracy, it is clear that be irrational, so by being subordinate in fuzzy mathematics Membership fuction determines that method solves the above problems, it is ensured that the accuracy of risk assessment.

In above-mentioned technical proposal, it is preferable that the computing formula of the node voltage mean value specification value is：

The computing formula of the too low more line desired value of the node voltage is：

The computing formula of the too high more line desired value of the node voltage is：

Wherein, U_avgFor the mean value of the node voltage, U_overBe the node voltage be higher than the critical value when electricity Pressure, U_lowerThe voltage being less than for the node voltage during critical value, q (x)_{Rise θ}、q(x)_{Drop θ}Described in the node voltage Weighted value, pi is the probability that arbitrary circuit or equipment i break down in the malfunction set, and Wi is circuit or failure i Important level, θ is the corresponding numbering of all nodes, U under arbitrary circuit or equipment i malfunctions_{Overvoltage node θ calculated values} For the magnitude of voltage in all node voltages higher than standard voltage value, U_{Lower voltage node θ calculated value}To be less than in all node voltages The magnitude of voltage of standard voltage value, U_{Overvoltage critical value}For default overtension critical value, U_{Low-voltage critical value}It is critical for default brownout Value,

The computing formula of the line transmission overload objective value is:

Wherein, Lover is the through-put power for exceeding through-put power rated value during line transmission, and it is circuit that q (x) rises θ The weighted value of through-put power, pi is the probability that arbitrary circuit described in the malfunction set or equipment i occur, W_iFor The important level of arbitrary circuit or equipment i, θ is all circuits under arbitrary circuit or equipment i malfunctions Corresponding numbering, I_{Overload circuit θ calculated values}It is more than the transmission work(of the circuit of the through-put power rated value of the circuit for through-put power Rate；I_{The effective limits of circuit θ}For the through-put power rated value of the circuit,

The computing formula of the equipment operating overload desired value is：

Wherein, E_overFor the operation power for exceeding operation power rating in equipment running process, q (x)_{Rise θ}For equipment operation The weighted value of power, pi is the probability that arbitrary circuit or equipment i break down in the malfunction set, and Wi is described arbitrary The important level of circuit or equipment i, θ is the corresponding volume of all equipment under arbitrary circuit or equipment i malfunctions Number, S_{Overload prevention device θ calculated values}To run the operation power of equipment of the power more than the operation power rating of the equipment； S_{The effective limits of equipment θ}Refer to the operation power rating of the equipment.

It is faulty to the institute in malfunction set to travel through in the technical scheme, calculate the faulty node of institute The too high more line desired value of average voltage desired value, node voltage, the too low more line desired value of node voltage, line transmission overload objective Value and equipment operating overload desired value, the risk assessment desired value of each failure in malfunction set is added, it is possible to Go out power distribution network operation risk assessment desired value.As such, it is possible to quickly and accurately provide detailed every risk assessment of each failure Index, the accuracy of the power distribution network risk assessment for greatly improving, furthermore it is also possible to be actually needed according to difference, flexibly modification is each The important level of each risk assessment index of individual failure, substantially increases practicality and the flexibility of power distribution network risk assessment, Usage range has been widened, the control to risk level has been enhanced, the safety coefficient of power distribution network has been improve.

According to a further aspect in the invention, a kind of power distribution network operation risk assessment system containing distributed power source is additionally provided System, including：Determining unit, for determining power distribution network in malfunction set；First computing unit, it is general according to default failure Rate assignment rule, calculates the probability that each failure occurs in the malfunction set；Second computing unit, according to default meter Rule is calculated, corresponding evaluation index value when calculating each failure in the malfunction set is corresponding with described each failure The probability that evaluation index value and described each failure occur, obtains the risk assessment desired value of each failure；3rd calculates Unit, according to the risk assessment desired value of each failure the operation risk assessment desired value of the power distribution network is determined.

In above-mentioned technical proposal, it is preferable that first computing unit specifically for：By the malfunction set point For line fault collection and other fault sets, the probability that the line fault collection occurs is set to into the first probability, by it is described other The probability that fault set occurs is set to the second probability, wherein, first probability is 1 with the second probability sum；According to institute Corresponding first probability of line fault collection is stated, and the line fault concentrates the length of the corresponding arbitrary circuit of arbitrary line fault The first ratio between degree and the total length of the corresponding all circuits of the line fault collection, calculates arbitrary line fault and sends out Raw probability；And according to corresponding second probability of described other fault sets, and arbitrary other events in described other fault sets The total long-term operating statistic for hindering corresponding longtime running statistical probability every other failure corresponding with described other fault sets is general The second ratio between rate, calculates the probability that described arbitrary other failures occur.

In above-mentioned technical proposal, it is preferable that also include：Second setting unit, is that the evaluation index value setting is important Grade, and the 3rd setting unit, are that the evaluation index value arranges corresponding weighted value according to the important level.

In above-mentioned technical proposal, it is preferable that also include：Critical numerical value processing unit, by presetting disposal methods The weighted value of every operation risk index in the power distribution network；

Second preset formula is：

Wherein, when operation risk index is node voltage mean value specification, a_maxFor the upper critical value of the node voltage, a_minFor the lower critical value of the node voltage, q (x)_Rise、q(x)_DropFor the weighted value of the node voltage, x is node voltage value, k For regulation coefficient, A_Rise、A_Drop、B_Rise、B_DropSetting value is, wherein, A_Rise、A_DropFor magnification function value, functional value is made in [0.005,1] In interval, B_Rise、B_DropFor setting tolerance size；

Wherein, U_avgFor the mean value of the node voltage, U_overBe the node voltage be higher than the critical value when electricity Pressure, U_lowerThe voltage being less than for the node voltage during critical value, q (x)_{Rise θ}、

q(x)_{Drop θ}For the weighted value of the node voltage, pi is arbitrary circuit or equipment in the malfunction set The probability that i breaks down, Wi is the important level of circuit or failure i, and θ is under arbitrary circuit or equipment i malfunctions The corresponding numbering of all nodes, U_{Overvoltage node θ calculated values}To be higher than the magnitude of voltage of standard voltage value in all node voltages, U_{Lower voltage node θ calculated value}For the magnitude of voltage in all node voltages less than standard voltage value, U_{Overvoltage critical value}For default overtension Critical value, U_{Low-voltage critical value}For default brownout critical value,

The computing formula of the line transmission overload objective value is:

Wherein, L_overFor the through-put power during line transmission more than through-put power rated value, q (x)_{Rise θ}For the circuit The weighted value of through-put power, pi is the probability that arbitrary circuit described in the malfunction set or equipment i occur, and Wi is described The important level of arbitrary circuit or failure i, θ is all circuit correspondences under arbitrary circuit or equipment i malfunctions Numbering, I_{Overload circuit θ calculated values}It is more than the through-put power of the circuit of the through-put power rated value of the circuit for through-put power； I_{The effective limits of circuit θ}For the through-put power rated value of the circuit,

The computing formula of the equipment operating overload desired value is：

Wherein, E_overFor the operation power for exceeding operation power rating in equipment running process, q (x)_{Rise θ}For the equipment The weighted value of operation power, pi is the probability that arbitrary circuit or equipment i break down in the malfunction set, and Wi is described The important level of arbitrary circuit or equipment i, θ is all equipment correspondences under arbitrary circuit or equipment i malfunctions Numbering, S_{Overload prevention device θ calculated values}To run the operation power of equipment of the power more than the operation power rating of the equipment； S_{The effective limits of equipment θ}Refer to the operation power rating of the equipment.

By above technical scheme, can according to different power distribution networks or same power distribution network different run times actual need Will, the important level of each risk indicator can be flexibly changed, and system can be provided from entirety and/or single index respectively Risk level, helps dispatcher to integrate, analyzes, refines substantial amounts of operation information in power distribution network, pre- for the safety of power distribution network Important directive function is played in alert and stable operation, and while every risk assessment index is quickly given, it is ensured that risk is commented The accuracy estimated, strengthens the control to risk level.

Description of the drawings

Fig. 1 shows the stream of the power distribution network operation risk assessment method containing distributed power source according to an embodiment of the invention Cheng Tu；

Fig. 2 shows the tool of the power distribution network operation risk assessment method containing distributed power source according to an embodiment of the invention Body flow chart；

Fig. 3 shows the block diagram of power distribution network operation risk assessment device according to an embodiment of the invention；

Fig. 4 shows the power distribution network operation risk assessment side containing distributed power source according to another embodiment of the invention The calculation flow chart of method；

Fig. 5 shows the power distribution network operation risk assessment side containing distributed power source according to another embodiment of the invention The Node power distribution system schematic diagram of power distribution network 33 of method.

Specific embodiment

It is below in conjunction with the accompanying drawings and concrete real in order to be more clearly understood that the above objects, features and advantages of the present invention Apply mode to be further described in detail the present invention.It should be noted that in the case where not conflicting, the enforcement of the application Feature in example and embodiment can be mutually combined.

Many details are elaborated in the following description in order to fully understand the present invention, but, the present invention may be used also Implemented with being different from other modes described here using other, therefore, protection scope of the present invention is not by described below Specific embodiment restriction.

Fig. 1 shows the stream of the power distribution network operation risk assessment method containing distributed power source according to an embodiment of the invention Cheng Tu.

As shown in figure 1, contain the power distribution network operation risk assessment method of distributed power source according to an embodiment of the invention, bag Include following steps：

Step 102, determines the malfunction set in power distribution network；

Step 104, according to default probability of malfunction assignment rule, each failure generation is general in calculating malfunction set Rate；

Step 106, according to default computation rule, corresponding assessment when calculating each failure generation in malfunction set Desired value, and the probability occurred according to the corresponding evaluation index value of each failure and each failure, obtain the risk of each failure Evaluation index value；

Step 108, according to the risk assessment desired value of each failure the operation risk assessment desired value of power distribution network is determined.

In above-mentioned technical proposal, it is preferable that default probability of malfunction assignment rule is specifically included：By malfunction set It is divided into line fault collection and other fault sets, the probability that line fault collection occurs is set to into the first probability, by other fault sets The probability of generation is set to the second probability, wherein, the first probability and the second probability sum are 1；It is corresponding according to line fault collection First probability, and length and the corresponding institute of line fault collection of the corresponding arbitrary circuit of the arbitrary line fault of line fault concentration There is the first ratio between the total length of circuit, calculate the probability that arbitrary line fault occurs；And according to other fault sets pair The second probability answered, and arbitrary corresponding longtime running statistical probability of other failures and other fault sets pair in other fault sets The second ratio between the total long-term operating statistic probability of the every other failure answered, calculates the general of arbitrary other failures generations Rate.

In above-mentioned technical proposal, it is preferable that evaluation index value includes overall operation desired value and individual event operating index value, Wherein, overall operation desired value includes node voltage mean value specification value, and individual event operating index value includes the too high more line of node voltage Desired value, node voltage too low more line desired value, line transmission overload objective value and equipment operating overload desired value.

In above-mentioned technical proposal, it is preferable that for evaluation index value, important level is set, and it is to comment according to important level Estimate desired value and corresponding weighted value is set.

Second preset formula is：

In above-mentioned technical proposal, it is preferable that the computing formula of node voltage mean value specification value is：

The computing formula of the too low more line desired value of node voltage is：

The computing formula of the too high more line desired value of node voltage is：

Wherein, U_avgFor the mean value of node voltage, U_overBe node voltage be higher than critical value when voltage, U_lowerFor section Point voltage is less than voltage during critical value, q (x)_{Rise θ}、q(x)_{Drop θ}For the weighted value of node voltage, pi is to appoint in malfunction set The probability that one circuit or equipment i break down, Wi is the important level of arbitrary circuit or failure i, θ be in arbitrary circuit or The corresponding numbering of all nodes, U under equipment i malfunctions_{Overvoltage node θ calculated values}For in all node voltages be higher than voltage standard The magnitude of voltage of value, U_{Lower voltage node θ calculated value}For the magnitude of voltage in all node voltages less than standard voltage value, U_{Overvoltage critical value}For default electricity Press through high critical value, U_{Low-voltage critical value}For default brownout critical value,

The computing formula of line transmission overload objective value is:

Wherein, L_overFor the through-put power during line transmission more than through-put power rated value, q (x)_{Rise θ}For line transmission The weighted value of power, pi is the probability that arbitrary circuit or equipment i break down in malfunction set, and Wi is arbitrary circuit Or the important level of failure i, θ is the corresponding numbering of all circuits, I under arbitrary circuit or equipment i malfunctions_{Overload circuit θ calculated values} It is more than the through-put power of the circuit of the through-put power rated value of circuit for through-put power；I_{The effective limits of circuit θ}For the through-put power volume of circuit Definite value,

The computing formula of equipment operating overload desired value is：

Wherein, E_overFor the operation power for exceeding operation power rating in equipment running process, q (x)_{Rise θ}For equipment operation The weighted value of power, pi is the probability that arbitrary circuit or equipment i break down in malfunction set, and Wi is arbitrary circuit Or the important level of equipment i, θ is the corresponding numbering of all devices under arbitrary circuit or equipment i malfunctions, S_{Overload prevention device θ calculated values} To run the operation power of equipment of the power more than the operation power rating of equipment；S_{The effective limits of equipment θ}The operation power volume of finger equipment Definite value.

Fig. 2 shows the tool of the power distribution network operation risk assessment method containing distributed power source according to an embodiment of the invention Body flow chart.

As shown in Fig. 2 contain the power distribution network operation risk assessment method of distributed power source according to an embodiment of the invention, tool Body is comprised the following steps：

Step 202, determines malfunction set and probability of malfunction assignment rule；

Step 204, according to the probability that probability of malfunction assignment rule, the probability that line fault is occurred and other failures occur P, q are entered as respectively, p+q=1 is made, that is, it is fixed value 1 to arrange total probability of malfunction sum, makes risk assessment index in different nets Still there is comparativity under network topology；

Whether step 206, failure judgement i is line fault, when judged result is to be, into step 208, when judgement knot When fruit is no, failure i is other failures, into step 210；

Step 208, makes the corresponding total line length of all line fault elements in malfunction set be L_sum, measure event The length of the circuit that barrier i is located is L_i, then the probability that failure i occurs is p_i=pL_i/L_sum；

Step 210, if comprising the m element that may be broken down in other failures, by the substance probability of malfunction of the m element Q is designated as respectively₁、q₂、…、q_m, meanwhile, by element manufacturing specification or the long-term observation to the m element, by the m element The longtime running statistical probability for breaking down is designated as a₁、a₂、…、a_m, then failure i (i ∈ m) occur probability be

Step 212, is operation risk setup measures important level, including particular importance, important and important, and foundation Important level is the corresponding weighted value of operation risk setup measures, by particular importance, important, important corresponding weighted value point It is not set to 5,2,1；

Step 214, by the weighted value of every operation risk index in power distribution network described in default disposal methods；

Second preset formula is：

Step 216, calculates respectively the operation risk desired value of failure i, and operation risk desired value includes node voltage average The too high more line desired value of desired value, node voltage, the too low more line desired value of node voltage, line transmission overload objective value and/or Equipment operating overload desired value：

The computing formula of node voltage mean value specification value is：

Wherein, U_avgFor the mean value of node voltage, U_overBe node voltage be higher than critical value when voltage, U_lowerFor section Point voltage is less than voltage during critical value, q (x)_{Rise θ}、q(x)_{Drop θ}For the weighted value of node voltage, pi is to appoint in malfunction set The probability that one circuit or equipment i break down, Wi is the important level of circuit or failure i, and θ is in arbitrary circuit or equipment The corresponding numbering of all nodes, U under i malfunctions_{Overvoltage node θ calculated values}For in all node voltages higher than standard voltage value Magnitude of voltage, U_{Lower voltage node θ calculated value}For the magnitude of voltage in all node voltages less than standard voltage value, U_{Overvoltage critical value}For default voltage mistake High critical value, U_{Low-voltage critical value}For default brownout critical value,

The computing formula of line transmission overload objective value is:

Wherein, Lover is more than the through-put power of through-put power rated value, q (x) during line transmission_{Rise θ}For circuit biography The weighted value of defeated power, pi is the probability that arbitrary circuit or equipment i break down in malfunction set, and Wi is any line Road or the important level of failure i, θ is the corresponding numbering of all circuits under arbitrary circuit or equipment i malfunctions, I_{Overload circuit θ calculated values}It is more than the through-put power of the circuit of the through-put power rated value of circuit for through-put power；I_{The effective limits of circuit θ}For the biography of circuit Defeated power rating,

The computing formula of equipment operating overload desired value is：

Wherein, Eover is to exceed the operation power for running power rating, q (x) in equipment running process_{Rise θ}For equipment fortune The weighted value of row power, pi is the probability that arbitrary circuit or equipment i break down in malfunction set, and Wi is any line Road or the important level of equipment i, θ is the corresponding numbering of all devices under arbitrary circuit or equipment i malfunctions, S_{Overload prevention device θ calculated values}To run the operation power of equipment of the power more than the operation power rating of equipment；S_{The effective limit in equipment θ roads}Finger equipment Operation power rating.

Step 218, with the operation risk desired value of failure i the probability of failure i generation is multiplied by, and obtains the final wind of failure i Dangerous evaluation index value

R_isk(x, t)=∑ p_i×V_i

Wherein, R_isk(x, t) is referred under t, and for the risk assessment numerical value of index x, x can be that node voltage is equal Value index, the too high more line index of node voltage, the too low more line index of node voltage, line transmission overload objective and/or equipment fortune Row overload objective, p_iFor the probability of the i that breaks down；V_iAfter the i that breaks down, the order of severity size that failure i is caused to system, I.e. various risk assessment desired values, including node voltage mean value specification value V (U_avg), too high more line desired value V of node voltage (U_over), the too low more line desired value V (U of node voltage_lower), line transmission overload objective value V (L_over) and/or equipment ran Carry desired value V (E_over)；

Step 220, it is faulty to the institute in malfunction set to travel through, go through after the completion of when faulty to institute, will The risk assessment desired value of each failure is added, and obtains power distribution network operation risk assessment desired value R=∑ R_isk(x,t)。

In the technical scheme, by arranging brand-new probability of malfunction assignment rule, using Fault enumeration algorithm, traversal system The imaginary fault set of system, with the operation risk desired value of failure the probability that the failure occurs is multiplied by, and quickly calculates institute faulty Risk assessment desired value, the risk assessment desired value obtained by superposition, can to obtain power distribution network operation risk assessment desired value Being actually needed in different run times according to different power distribution networks or same power distribution network, can flexibly change each risk indicator Important level, and respectively the risk level of system can be provided from entirety and/or single index, help the whole splitting or integrating of dispatcher Analysis, refine substantial amounts of operation information in power distribution network, for power distribution network safe early warning and stable operation play important guidance and make With, and while every risk assessment index is quickly given, it is ensured that the accuracy of risk assessment, strengthen the palm to risk level Control.

Fig. 3 shows the block diagram of power distribution network operation risk assessment device according to an embodiment of the invention.

As shown in figure 3, power distribution network operation risk assessment device 300 according to an embodiment of the invention, including：Determining unit 302, for determining power distribution network in malfunction set；First computing unit 304, advises according to default probability of malfunction assignment Then, the probability that each failure occurs in malfunction set is calculated；Second computing unit 306, according to default computation rule, meter Corresponding evaluation index value when calculating each failure in malfunction set, with the corresponding evaluation index value of each failure and each event The probability that barrier occurs, obtains the risk assessment desired value of each failure；3rd computing unit 308, according to the risk of each failure Evaluation index value determines the operation risk assessment desired value of power distribution network.

In above-mentioned technical proposal, it is preferable that the first computing unit specifically for：Malfunction set is divided into into circuit event Barrier collection and other fault sets, by the probability that line fault collection occurs the first probability is set to, the probability that other fault sets are occurred The second probability is set to, wherein, the first probability and the second probability sum are 1；According to corresponding first probability of line fault collection, with And line fault concentrate the corresponding arbitrary circuit of arbitrary line fault length and the corresponding all circuits of line fault collection it is total The first ratio between length, calculates the probability that arbitrary line fault occurs；And it is corresponding second general according to other fault sets In rate, and other fault sets the corresponding longtime running statistical probability of arbitrary other failures it is corresponding with other fault sets it is all its The second ratio between the total long-term operating statistic probability of his failure, calculates the probability that arbitrary other failures occur.

In above-mentioned technical proposal, it is preferable that also include：Second setting unit 310, it is important etc. to be that evaluation index value is arranged Level, and the 3rd setting unit 312, are that evaluation index value arranges corresponding weighted value according to important level.

In above-mentioned technical proposal, it is preferable that also include：314 critical numerical value processing units, at default processing method Manage the weighted value of every operation risk index in the power distribution network；

Second preset formula is：

The computing formula of line transmission overload objective value is:

Wherein, Lover is more than the through-put power of through-put power rated value, q (x) during line transmission_Riseθ is circuit biography The weighted value of defeated power, pi is the probability that arbitrary circuit or equipment i break down in malfunction set, and Wi is any line Road or the important level of failure i, θ is the corresponding numbering of all circuits under arbitrary circuit or equipment i malfunctions, I_{Overload circuit θ calculated values}It is more than the through-put power of the circuit of the through-put power rated value of circuit for through-put power；I_{The effective limits of circuit θ}For the biography of circuit Defeated power rating,

The computing formula of equipment operating overload desired value is：

Wherein, Eover is to exceed the operation power for running power rating, q (x) in equipment running process_{Rise θ}For equipment fortune The weighted value of row power, pi is the probability that arbitrary circuit or equipment i break down in malfunction set, and Wi is any line Road or the important level of equipment i, θ is the corresponding numbering of all devices under arbitrary circuit or equipment i malfunctions, S_{Overload prevention device θ calculated values}To run the operation power of equipment of the power more than the operation power rating of equipment；S_{The effective limits of equipment θ}The fortune of finger equipment Row power rating.

Fig. 4 shows the power distribution network operation risk assessment side containing distributed power source according to another embodiment of the invention The calculation flow chart of method.

As shown in figure 4, the distribution network operation containing distributed power source of another embodiment according to an embodiment of the invention Methods of risk assessment, comprises the following steps：

Step 402, each node electric parameters of input power distribution network calculate current trend, the big Small Indicators of input weight；

Step 404, determines the malfunction set { L of power distribution network₁,L₂,…,L_n,O_n+1,O_n+2,…,O_n+m, wherein, L refers to Line fault element；N refers to total n bars branch road, and O refers to other failure elements, the such as transformer in distribution, and m refers to total m element There is the possibility that other failures occur；

Step 406, according to probability of malfunction assignment rule, assigns to the probability that each failure in malfunction set occurs Value；

Step 408, enumerates respectively all of substance failure in malfunction set, makes i=0；

Step 410, under certain malfunction i, the side that power distribution network passes through regulation and control part disconnecting switch, interconnection switch etc. Formula, using with the application software (NOR) for realizing network reconfiguration function, by the software real distribution Running State is simulated Switching, is managed grid optimization and reconstructs, and new network topology is obtained, with during the power failure for shortening user as much as possible Between；

Step 412, calculates new network topology trend；

Step 414, calculates the risk assessment desired value of each failure in malfunction set；

Step 416, judges whether to travel through all elements in malfunction set, when judged result is no, enters Step 418, when judged result is to be, into step 420；

Step 418, makes i=i+1, return to step 410 proceed the calculating of next failure element；

Step 420, the risk assessment desired value of each failure is added, and obtains power distribution network operation risk assessment desired value.

In the technical program, for the randomness that failure in power distribution network occurs, devise a kind of based on Fault enumeration calculation The power distribution network operation risk assessment method containing distributed power source of method, with institute in the circuit containing protective relaying device and power distribution network There is equipment to be malfunction set, all substance failures in traversal malfunction set help dispatcher to integrate, analyze, carry Refining power distribution network in substantial amounts of operation information, for power distribution network safe early warning and stable operation play important directive function, most Power distribution network operation risk assessment index is calculated eventually, and while every risk assessment index is quickly given, it is ensured that risk The accuracy of assessment, strengthens the control to risk level.

The Node power distribution system of power distribution network 33 is as shown in figure 5, have 32 branch roads, 5 interconnection switch branch roads (such as dotted line in the net It is shown), 1 electric power network head end reference voltage 12.66kV, three phase power quasi- value take 10MVA, network total load 5084.26+ J2547.32kVA, node numeral represents node number, and corresponding node has different size of load.When certain line in power distribution network After the failure of road, corresponding interconnection switch meeting action recovers the power supply of the end node of faulty line two.

Table 1 shows the node load table of the Node power distribution system of power distribution network 33.

Nonserviceable and contain 3 common transformers at 10,15,20 nodes, 3 transformer longtime runnings in set Under probability of malfunction it is identical；There is a photovoltaic generation to access the power distribution network in 15 nodes, in operation risk assessment the moment is calculated, its Capacity is set as 230KVA；All circuits are buried cable, and 0-1,1-2,2-3,3-4,4-5 line length is 1km, 5- 6th, 6-7,7-8 ..., 31-32 line lengths be 2km；Overtension critical value is set to 1.05p.u., voltage mistake in power distribution network Low critical value is set to 0.93p.u.；Power distribution network obtains in real time the voltage x current situation of each node, for the node that cannot be obtained or Region, with method of estimation the parameters such as the node voltage electric current are obtained；During power distribution network line fault, system can be held by contact The power supply for cut-offfing combination recovery faulty line of pass etc.；When certain line fault, if the corresponding node in circuit two ends is i, i+ 1, then the nearest node j of two nodes of distance have interconnection switch for action, the confession between malfunctioning node i and i+1 is recovered rapidly Electricity.

Table 1

Set according to above-mentioned condition, probability of malfunction distribution is only relevant with line length, meanwhile, other fault elements contain 3 Common transformer equipment, sets the total failare probability of 3 common transformers as 0.2, long-term observation data display, 3 transformers Probability of malfunction is identical, 3 transformer weighteds, and transformer weight is 5 at node 10, and transformer weight is 2 at node 15, section Transformer weight is 2 at point 20；Therefore, at node 10,15,20 probability of malfunction of transformer respectively by following 3 formulas gained：

The total probability of line failure is 0.8, unit length circuit probability of happening be 0.8/ (5 × 1+27 × 2)= 0.01355932203, each bar circuit unit length circuit probability of happening is multiplied by line length and is the line failure Probability, for example, the probability of 1-2 line failures is 0.01355932203 × 1=0.01355932203.

Obtain the information such as the voltage x current of distribution in real time by the sensor in power distribution network, carry out Load flow calculation emulation, obtain Obtain the Power Flow Information such as the voltage x current of each node and the power of each bar line transmission；The present embodiment passes through matlab software programmings Risk assessment algorithm, by calling matpower software kits Load flow calculation is realized.

Under normal circumstances, power distribution network operation information is obtained by Load flow calculation, enumerates following information：

Voltage minimum is 0.913p.u. in each node, and node number is 18；Voltage peak is 1p.u., and node number is 1；

Fault traversal is carried out to malfunction set, an element failure in malfunction set is assumed every time, if this Line fault does not directly result in each load bus dead electricity of distribution network systems, and the topology for illustrating now distribution does not change, then directly Tap into the distribution Load flow calculation after row failure；Otherwise, related interconnection switch, block switch etc. need action to ensure fault wire The end node of road two restores electricity, and then, the system load flow in the case of distribution changes is calculated, according to the calculating of each index Formula calculates corresponding risk factors value V_i；

When providing transformer fault at 5-6 line faults, and node 10 separately below, node voltage average risk indicator Computational methods and process；Other each individual event operating index are carried out by identical method

When 5-6 line faults,

1) 5-6 line faults probability P_5-6For 0.02711864406；

2) by being calculated, after failure, 0～No. 32 node voltage perunit value is respectively：1.0000,0.9971, 0.9876,0.9835,0.9796,0.9697,0.9518,0.9529,0.9476,0.9427,0.9420,0.9409,0.9360, 0.9342,0.9333,0.9326,0.9306,0.9302,0.9950,0.9773,0.9723,0.9717,0.9840,0.9774, 0.9741,0.9679,0.9653,0.9542,0.9461,0.9426,0.9386,0.9377,0.9374；

3) corresponding node voltage average risk indicator is during 5-6 circuits substance failure：

Wherein, circuit 5-6 weights W_5-6For 1, q (x)_Rise、q(x)_DropFormula (7) (8), and A in this example are corresponded to respectively_Rise、A_Drop、 B_Rise、B_Drop4000,4000,0.99,1.02 are taken respectively；

At No. 10 nodes during transformer fault,

1) transformer fault probability P at No. 10 nodes₁₀For 0.1111111, weight W₁₀For 5；

2) after failure, 0～No. 32 node voltage perunit value is respectively：1.0000,0.9971,0.9833,0.9760, 0.9688,0.9509,0.9477,0.9432,0.9375,0.9323,0.9316,0.9303,0.9242,0.9219,0.9205, 0.9192,0.9171,0.9167,0.9966,0.9930,0.9923,0.9916,0.9797,0.9730,0.9697,0.9490, 0.9465,0.9350,0.9268,0.9233,0.9191,0.9182,0.9179；

3) transformer substance failure at No. 10 nodes, institute's calculate node average voltage risk single index numerical value is：

Wherein, q (x)_Rise、q(x)_DropFormula (7) (8), A in example are corresponded to respectively_Rise、A_Drop、B_Rise、B_DropCircuit is calculated in value and A The value of 5-6 failures keeps identical；

4) according to 3) the step of, other substance fault indices are calculated in failure collection successively, finally carry out cumulative asking With, finish node average voltage risk indicator is drawn, other indexs are also carried out according to identical algorithms.

In the present invention, term " first ", " second ", " the 3rd " are only used for the purpose for describing, and it is not intended that indicating Or hint relative importance

Technical scheme is described in detail above in association with accompanying drawing, by technical scheme, being capable of basis Different power distribution networks or same power distribution network being actually needed in different run times, can flexibly change the important of each risk indicator Grade, and respectively the risk level of system can be provided from entirety and/or single index, help dispatcher to integrate, analyze, carry Refining power distribution network in substantial amounts of operation information, for power distribution network safe early warning and stable operation play important directive function, and While every risk assessment index is quickly provided, it is ensured that the accuracy of risk assessment, strengthen the control to risk level.

The preferred embodiments of the present invention are the foregoing is only, the present invention is not limited to, for the skill of this area For art personnel, the present invention can have various modifications and variations.It is all within the spirit and principles in the present invention, made any repair Change, equivalent, improvement etc., should be included within the scope of the present invention.

Claims

1. a kind of power distribution network operation risk assessment method containing distributed power source, it is characterised in that include：

Determine the malfunction set in power distribution network；

According to default probability of malfunction assignment rule, the probability that each failure occurs in the malfunction set is calculated；

According to default computation rule, corresponding evaluation index value when calculating each failure generation in the malfunction set, And the probability occurred according to the corresponding evaluation index value of described each failure and described each failure, obtain each failure Risk assessment desired value；

The operation risk assessment desired value of the power distribution network is determined according to the risk assessment desired value of each failure；

The default probability of malfunction assignment rule is specifically included：

The malfunction set is divided into into line fault collection and other fault sets, the probability that the line fault collection occurs is set Be set to the first probability, the probability that described other fault sets occur be set to into the second probability, wherein, first probability with it is described Second probability sum is 1；

Arbitrary corresponding of line fault is concentrated according to corresponding first probability of the line fault collection, and the line fault The first ratio between the total length of the length of one circuit and the corresponding all circuits of the line fault collection, calculates described arbitrary The probability that line fault occurs；And

According to corresponding second probability of described other fault sets, and the corresponding length of arbitrary other failures in described other fault sets Between the total long-term operating statistic probability of phase operating statistic probability every other failure corresponding with described other fault sets Two ratios, calculate the probability that described arbitrary other failures occur；

The power distribution network operation risk assessment method containing distributed power source, also includes：

The weighted value of every operation risk index in by presetting disposal methods power distribution network；

The default processing method includes：

The weighted value of every operation risk index is fitted according to the first preset formula and the second preset formula, its In：First preset formula is：

Second preset formula is：

Wherein, when operation risk index is node voltage mean value specification, a_maxFor upper critical value, a of the node voltage_minFor The lower critical value of the node voltage, q (x)_Rise、q(x)_DropFor the weighted value of the node voltage, x is node voltage value, and k is tune Integral coefficient, A_Rise、A_Drop、B_Rise、B_DropSetting value is, wherein, A_Rise、A_DropFor magnification function value, make functional value interval in [0.005,1] It is interior, B_Rise、B_DropFor setting tolerance size；

When operation risk index is that node voltage is too high gets over line index, a_maxFor the upper critical value of the node voltage, q (x)_Rise For the weighted value of the node voltage, x is node voltage value, and k is regulation coefficient, A_Rise、B_RiseSetting value is, wherein, A_RiseFor Magnification function value, makes functional value interval interior in [0.005,1], B_RiseFor setting tolerance size；

When operation risk index is that node voltage is too low gets over line index, a_minFor the lower critical value of the node voltage, q (x)_Drop For the weighted value of the node voltage, x is node voltage value, and k is regulation coefficient, A_Drop、B_DropSetting value is, wherein, A_DropFor Magnification function value, makes functional value interval interior in [0.005,1], B_DropFor setting tolerance size；

When operation risk index is line transmission overload objective, a_maxFor upper critical value, a of line transmission power_minFor described The lower critical value of line transmission power, q (x)_Rise、q(x)_DropFor the weighted value of the line transmission power, x is line transmission power Value, k is regulation coefficient, A_Rise、A_Drop、B_Rise、B_DropSetting value is, wherein, A_Rise、A_DropFor magnification function value, functional value is set to exist [0.005,1] in interval, B_Rise、B_DropFor setting tolerance size；When operation risk index is equipment operating overload index, a_max For upper critical value, a that equipment runs power_minFor the lower critical value that the equipment runs power, q (x)_Rise、q(x)_DropSet for described The weighted value of received shipment row power, x is that equipment runs performance number, and k is regulation coefficient, A_Rise、A_Drop、B_Rise、B_DropSetting value is, wherein, A_Rise、A_DropFor magnification function value, make functional value interval interior in [0.005,1], B_Rise、B_DropFor setting tolerance size；

The computing formula of the node voltage mean value specification value is：

Wherein, U_avgFor the mean value of the node voltage, U_overBe the node voltage be higher than the critical value when voltage, U_lowerThe voltage being less than for the node voltage during critical value, q (x)_{Rise θ}、q(x)_{Drop θ}For the weighted value of the node voltage, p_iFor the probability that arbitrary circuit or equipment i in the malfunction set break down, W_iFor arbitrary circuit or equipment i Important level, θ is the corresponding numbering of all nodes, U under arbitrary circuit or equipment i malfunctions_{Overvoltage node θ calculated values} For the magnitude of voltage in all node voltages higher than standard voltage value, U_{Lower voltage node θ calculated value}To be less than in all node voltages The magnitude of voltage of standard voltage value, U_{Overvoltage critical value}For default overtension critical value, U_{Low-voltage critical value}It is critical for default brownout Value,

The computing formula of the line transmission overload objective value is:

Wherein, L_overFor the through-put power during line transmission more than through-put power rated value, q (x)_{Rise θ}For line transmission power Weighted value, p_iFor the probability that circuit or equipment i described in the malfunction set break down, W_iFor circuit or equipment i Important level, θ is the corresponding numbering of all circuits, I under arbitrary circuit or equipment i malfunctions_{Overload circuit θ calculated values}For Through-put power of the through-put power more than the circuit of the through-put power rated value of the circuit；I_{The effective limits of circuit θ}For the circuit The through-put power rated value,

The computing formula of the equipment operating overload desired value is：

Wherein, E_overFor the operation power for exceeding operation power rating in equipment running process, q (x)_{Rise θ}Power is run for equipment Weighted value, p_iFor the probability that arbitrary circuit or equipment i in the malfunction set break down, W_iFor arbitrary circuit Or the important level of equipment i, θ is the corresponding numbering of all equipment under arbitrary circuit or equipment i malfunctions, S_{Overload prevention device θ calculated values}To run the operation power of equipment of the power more than the operation power rating of the equipment；S_{The effective limits of equipment θ}Refer to The operation power rating of the equipment.

2. the power distribution network operation risk assessment method containing distributed power source according to claim 1, it is characterised in that described Evaluation index value includes overall operation desired value and individual event operating index value, wherein, the overall operation desired value includes node Average voltage desired value, the individual event operating index value includes the too high more line desired value of node voltage, the too low more line of node voltage Desired value, line transmission overload objective value and equipment operating overload desired value.

3. the power distribution network operation risk assessment method containing distributed power source according to claim 2, it is characterised in that also wrap Include：

For the evaluation index value, important level is set, and

It is that the evaluation index value arranges corresponding weighted value according to the important level.

4. a kind of power distribution network operation risk assessment system containing distributed power source, it is characterised in that include：

Determining unit, for determining power distribution network in malfunction set；

First computing unit, according to default probability of malfunction assignment rule, calculates each failure in the malfunction set and sends out Raw probability；

Second computing unit, it is corresponding when calculating each failure in the malfunction set to comment according to default computation rule Estimate desired value, the probability occurred with the corresponding evaluation index value of described each failure and described each failure, obtain it is described each The risk assessment desired value of failure；

3rd computing unit, according to the risk assessment desired value of each failure the operation risk assessment of the power distribution network is determined Desired value；

First computing unit specifically for：

The power distribution network operation risk assessment system containing distributed power source, also includes：

Critical numerical value processing unit, by the weighted value of every operation risk index in default disposal methods power distribution network；

The default processing method includes：According to the first preset formula and the second preset formula to every operation risk index Weighted value be fitted, wherein：First preset formula is：

Second preset formula is：

When operation risk index is line transmission overload objective, a_maxFor upper critical value, a of line transmission power_minFor described The lower critical value of line transmission power, q (x)_Rise、q(x)_DropFor the weighted value of the line transmission power, x is line transmission power Value, k is regulation coefficient, A_Rise、A_Drop、B_Rise、B_DropSetting value is, wherein, A_Rise、A_DropFor magnification function value, functional value is set to exist [0.005,1] in interval, B_Rise、B_DropFor setting tolerance size；

When operation risk index is equipment operating overload index, a_maxFor upper critical value, a that equipment runs power_minFor described Equipment runs the lower critical value of power, q (x)_Rise、q(x)_DropFor the weighted value that the equipment runs power, x is that equipment runs power Value, k is regulation coefficient, A_Rise、A_Drop、B_Rise、B_DropSetting value is, wherein, A_Rise、A_DropFor magnification function value, functional value is set to exist [0.005,1] in interval, B_Rise、B_DropFor setting tolerance size；

The computing formula of the node voltage mean value specification value is：

Wherein, U_avgFor the mean value of the node voltage, U_overBe the node voltage be higher than the critical value when voltage, U_lowerThe voltage being less than for the node voltage during critical value, q (x)_{Rise θ}、q(x)_{Drop θ}For the power of the node voltage Weight values, p_iFor the probability that arbitrary circuit or equipment i in the malfunction set break down, Wi is for arbitrary circuit or sets The important level of standby i, θ is the corresponding numbering of all nodes under arbitrary circuit or equipment i malfunctions, U_{Overvoltage node θ calculated values}For the magnitude of voltage in all node voltages higher than standard voltage value, U_{Lower voltage node θ calculated value}For all nodes Less than the magnitude of voltage of standard voltage value, U in voltage_{Overvoltage critical value}For default overtension critical value, U_{Low-voltage critical value}For default electricity Low critical value is pressed through,

The computing formula of the line transmission overload objective value is:

Wherein, L_overFor the through-put power during line transmission more than through-put power rated value, q (x)_{Rise θ}For line transmission power Weighted value, p_iFor the probability that arbitrary circuit or equipment i described in the malfunction set break down, W_iFor described arbitrary The important level of circuit or equipment i, θ is the corresponding volume of all circuits under arbitrary circuit or equipment i malfunctions Number, I_{Overload circuit θ calculated values}It is more than the through-put power of the circuit of the through-put power rated value of the circuit for through-put power； I_{The effective limits of circuit θ}For the through-put power rated value of the circuit,

The computing formula of the equipment operating overload desired value is：

5. the power distribution network operation risk assessment system containing distributed power source according to claim 4, it is characterised in that described Evaluation index value includes overall operation desired value and individual event operating index value, wherein, the overall operation desired value includes node Average voltage desired value, the individual event operating index value includes the too high more line desired value of node voltage, the too low more line of node voltage Desired value, line transmission overload objective value and equipment operating overload desired value.

6. the power distribution network operation risk assessment system containing distributed power source according to claim 5, it is characterised in that also wrap Include：

Second setting unit, is that the evaluation index value arranges important level, and

3rd setting unit, is that the evaluation index value arranges corresponding weighted value according to the important level.