CN104021268B - A kind of transmission cross-section economic electric transmission power based on risk analyses determines method online - Google Patents

Abstract

The invention discloses a kind of transmission cross-section economic electric transmission power based on risk analyses determines method online, belong to Power System and its Automation technical field.Online acquisition grid model data of the invention, divides equally transmitted power interval, the economic benefit that transmits electricity under each transmitted power of parallel computation and system safety and stability risk between the transmitted power bound of transmission cross-section, and then calculates transmission of electricity risk benefit under the transmitted power；Again by risk benefit of transmitting electricity under com-parison and analysis difference transmitted power, the optimal economic electric transmission performance number of transmission cross-section is determined.The present invention considers transmission of electricity benefit and system safety hazards, propose transmission cross-section optimal economic conveying power and determine method online, can achieve the economy of transmission of electricity and effective balance of system stability, be beneficial to the nargin that transmission cross-section is made full use of in consideration system security constraint premise, improve economy and the safety of Operation of Electric Systems.

Description

A kind of transmission cross-section economic electric transmission power based on risk analyses determines method online

Technical field

The invention belongs to Power System and its Automation technical field, more precisely the present invention relates to a kind of be based on risk The transmission cross-section economic electric transmission power of analysis determines method online.

Background technology

The ability to transmit electricity of transmission cross-section is the important indicator of dispatching of power netwoks operation department concern.For ensureing power system security Stable operation, the actual section ability to transmit electricity that formulates also are subject in addition to the thermally-stabilised of equipment itself, the constraint of insulating requirements is subject to The constraint of the system security and stability such as power system transient stability, voltage stabilization, frequency stable.《Guiding rules of power system safety and stability》Rule Determine to take no action to should ensure that system stable operation under N-1 failures, emergent control measure under N-2 failures, can be taken to ensure system Stable operation, effective guarantee China's power system safe and stable operation for many years, but there is also certain limitation：Due to not having The probability for having consideration different faults to occur or probability, the consequence for also not accounting for bringing after different faults cause system unstability are poor Different, caused by this deterministic treatment principle, one of problem is the ability to transmit electricity for seriously constraining transmission cross-section, have impact on The economic benefit of transmission of electricity.

Billinton, Kurugan et al. divide in the probability of assessment different faults type, the position of fault, critical clearing time On the basis of cloth characteristic, it is proposed that a kind of probabilistic method of assessment system stability, although it is contemplated that the difference of failure possibility occurrence Different, but which has the disadvantage not consider the probability for causing unstability and consequence of failure, thus just cannot Comprehensive Evaluation failure serious Degree.Methods of risk assessment by the risk on system and its affects to carry out comprehensive assessment, can give from the angle of economic cost Go out the order of severity difference of different faults, be suitably applied the occasion that balance economy and security and stability have contradiction, and auxiliary Help others make the reason decision-making of the moderate controllable, better economic benefit of risk.But had not yet to see based on risk analysis method so far Determine the economic electric transmission power of transmission cross-section, so as to the report for instructing management and running to control.

Extensive new energy power generation grid-connection is run and the optimization on a large scale by transmission cross-section long distance power transmission for resource is matched somebody with somebody Put, energy-conserving and environment-protective create huge economic benefit, the constraint yet with system security and stability causes the actual transmission of electricity of section Power is seriously restricted, and the electric power system dispatching operation method based on traditional definitiveness, conservatism is stable in safeguards system But the economic benefit of transmission of electricity is sacrificed while property, and this present situation needs change badly.Method based on risk considers economy and is System stability effective balance, for formulate transmission cross-section optimal economic transmitted power provide a kind of effective ways, therefore this Bright be intended to by system safety and stability risk analyses, and consider transmission of electricity benefit and system safety hazards, propose transmission cross-section Optimal economic conveying power determines method online, is desired for management and running decision-making and provides reference.

Content of the invention

The purpose of the present invention is：In order to overcome the deficiencies in the prior art, a kind of transmission cross-section based on risk analyses is given Economic electric transmission power determines method online.The method is considered transmission of electricity benefit and is by system safety and stability risk analyses System security risk, online determination transmission cross-section optimal economic conveying power.When transmission cross-section is operated near economic electric transmission power, The economy that can be transmitted electricity with active balance and system safety and stability risk, obtain the scheduling fortune that risk is sane, economic benefit is good Row strategy.Regulation and control department arranges subsequent period transmission cross-section transmitted power according to the transmission cross-section economy conveying power for determining online Size, contributes to the level that becomes more meticulous for lifting management and running, ensures safety and the economy of Operation of Electric Systems.

Specifically, the present invention is realized using following technical scheme, is comprised the following steps：

1) grid equipment model and parameter, current operating condition, transmission cross-section examination are obtained online at power grid regulation center Forecast failure collection and its probability of happening, transmitted power upper limit P of transmission cross-section_maxWith lower limit P_min；

2) by the transmitted power of transmission cross-section in its lower limit P_minWith upper limit P_maxBetween be divided into M equal portions, obtain between bound Between different transmitted power P_j：

3) different transmitted power P are asked for respectively_jUnder transmission of electricity risk benefit Y_dea(P_j)；

4) each P of comparison_jUnder transmission of electricity risk benefit, determine approximation P of economic electric transmission power_sim：

P_sim=P_k, and Y_dea(P_k)=max { Y_dea(P_j) (k 1～M-1 of ∈, j=1～M-1) (2)

5) willInterval is divided into M ' equal portions, obtains between the interval up and down Different section transmitted powers between limitJ=1～M ' -1；Ask for respectively Different transmitted power values P_j' under transmission of electricity risk benefit Y_dea(P_j′)；

6) each P of comparison_j' under transmission of electricity risk benefit, determine the economic electric transmission power P of transmission cross-section_opt：

P_opt=P_k', and Y_dea(P_k')=max { Y_dea(P_j') (k ∈ 1～M ' -1, j=1～M ' -1) (3).

Above-mentioned technical proposal is further characterized by, the step 1) in, transmitted power upper limit P_maxFrom power grid regulation portion Door is obtained and has contemplated that transmission cross-section equipment is thermally-stabilised and insulating requirements are constrained, transmitted power lower limit P_minTrue according to scheduling requirement Fixed, P if without scheduling requirement_minValue is zero.

Above-mentioned technical proposal is further characterized by, the step 3) or step (5) in transmission of electricity risk benefit ask for Specifically include following steps：

3-1) in the giving of transmission cross-section, receiving end is scaled generator output and payload so that section of interest Transmitted power be P_jOr P_j′；

3-2) in line computation transmission cross-section transmitted power P_jOr P_j' under the emergent control measure that optimizes under each forecast failure；

3-3) transmitted power P is asked for by formula (4)_jOr P_jEconomic benefit E of ' lower transmission of electricity_tra(P_j) or E_tra(P_j′)：

In formula, T_obvIt is the time cycle in line computation transmission of electricity risk benefit；C_uitFor the economic benefit that unit conveys electric energy；

3-4) transmitted power P is asked for by formula (5)_jOr P_j' under system unstability risk R_sys(P_j) or R_sys(P_j′)：

In formula (5), N is the forecast failure number of transmission cross-section examination；P_r(i) be failure i in time T_obvInterior generation is general Rate；J (i) is the total cost for making system keep stable emergent control measure under failure i, according to step 3-2) obtained by urgent Control measure are calculated, and method is as follows：

In formula (6), K_gMachine number is cut for emergent control under failure i；ΔP_g(i,k₁) it is kth under failure i₁Individual cut machine measure Cut machine amount；C_g(k₁) it is kth₁The individual loss cost for cutting machine measure unit of electrical energy；T_g(i,k₁) it is kth under failure i₁Individual cut unit Recover after Failure elimination to the required time estimated value of bringing normally into operation；C_g-rst(k₁) it is kth₁Individual cut unit recovers to put into operation generation Valency；K_lCount for emergent control cutting load under failure i；ΔP_l(i,k₂) it is kth under failure i₂The cutting load amount of individual cutting load point；C_l (k₂) it is kth₂Individual cutting load unit of electrical energy loss；T_l(i,k₂) it is kth under failure i₂Individual cutting load point recovers to normal power supply institute Take time；

3-5) transmitted power P is asked for by formula (7)_jOr P_j' under transmission of electricity risk benefit Y_dea(P_j) or Y_dea(P_j′)：

Above-mentioned technical proposal is further characterized by, M=N_C+ 1, N_CFor computer check figure；WhenIt is whole During number,WhenWhen being not integer, M ' values be more thanMinimum Integer, wherein ε_PFor computational accuracy.

Above-mentioned technical proposal is further characterized by, the step 3) and step 5) in, for different transmitted power values Lower transmission of electricity risk benefit, improves computational efficiency using by transmitted power parallel computation.

Beneficial effects of the present invention are as follows：The present invention propose transmission cross-section transmit electricity under a certain transmitted power benefit, be System safety and stability risk and the computational methods of transmission of electricity risk benefit, set up the online method for determining economic electric transmission power, can be electricity The adjustment of the Force system method of operation and control decision etc. provide more specifically quantitative analysiss and decision support；Propose by two steps The method of risk benefit of respectively transmitting electricity under the interval parallel computation difference transmitted power of transmission of electricity, is conducive to improving computational efficiency.This Bright implement can active balance transmission of electricity economy and system safety and stability risk, obtain that risk is sane, economic benefit is good Management and running strategy, improves economy and the safety of Operation of Electric Systems.

Description of the drawings

Flow charts of the Fig. 1 for the inventive method.

Specific embodiment

With reference to the accompanying drawings and with reference to example the present invention is described in further detail.

In Fig. 1, step 1 is described, and obtains grid equipment model and parameter, current operation online from power grid regulation center (probability of happening of failure is according to operating in power grid regulation portion for operating mode, the forecast failure collection of transmission cross-section examination and its probability of happening Other support systems of door or application software are obtained)；Obtain from power grid regulation department and have contemplated that transmission cross-section equipment is thermally-stabilised, exhausted Edge requires upper limit P of constraint_max；According to the transmitted power lower limit P that scheduling requirement determines_min(if not requiring, value is Zero), P_minCan also be empirically determined according to dispatching.

In Fig. 1, step 2 is described, by the transmitted power of transmission cross-section in its lower limit P_minWith upper limit P_maxBetween be divided into M etc. Part, respectively obtain different transmitted power P_j：

In formula (1), M=N_C+ 1, N_CFor computer check figure.

In Fig. 1, step 3 is described, and asks for different transmitted power P respectively_jUnder transmission of electricity risk benefit Y_dea(P_j).Right In each transmitted power P_j(j=1～M-1), calculates its risk benefit Y of transmitting electricity respectively using by the parallel method of transmitted power_dea (P_j), for a certain transmitted power P_jUnder transmission of electricity risk benefit Y_dea(P_j), its calculating process comprises the steps.

Step 3-1：In the sending of transmission cross-section, receiving end is scaled generator output and payload so that of interest The transmitted power of section is P_j；

Step 3-2：In line computation transmission cross-section transmitted power P_jThe emergent control measure of lower optimization, the emergent control measure Ripe business software can be utilized to solve；

Step 3-3：Transmitted power P is asked for by formula (2)_jEconomic benefit E of lower transmission of electricity_tra(P_j)：

E_tra(P_j)=P_j×T_obv×C_uit(2)

In formula, T_obvIt is the time cycle in line computation transmission of electricity risk benefit, typically can use T_obv=1h；C_uitDefeated for unit The economic benefit of power transmission energy.

Step 3-4：Transmitted power P is asked for by formula (3)_jRisk R of lower system unstability_sys(P_j)：

In formula (3), N is the forecast failure number of transmission cross-section examination；P_r(i) be failure i in time T_obvInterior generation is general Rate；J (i) is the total cost for making system keep stable emergent control measure under failure i, according to step 3-2 obtained by urgent Control measure are calculated, and method is as follows：

In formula (4), K_gMachine number is cut for emergent control under failure i；ΔP_g(i,k₁) it is kth under failure i₁Individual cut machine measure Cut machine amount；C_g(k₁) it is kth₁The individual loss cost for cutting machine measure unit of electrical energy；T_g(i,k₁) it is kth under failure i₁Individual cut unit Recover after Failure elimination to the required time estimated value of bringing normally into operation, the desirable historical statistical data meansigma methodss of its value；C_g-rst (k₁) it is kth₁Individual cut unit recovers the cost that puts into operation；K_lCount for emergent control cutting load under failure i；ΔP_l(i,k₂) it is failure Kth under i₂The cutting load amount of individual cutting load point；C_l(k₂) it is kth₂Individual cutting load unit of electrical energy loss；T_l(i,k₂) under failure i Kth₂The time required to individual cutting load point recovers to normal power supply, the desirable historical statistical data meansigma methodss of its value.

Step 3-5：Transmitted power P is asked for by formula (5)_jUnder transmission of electricity risk benefit Y_dea(P_j)：

Y_dea(P_j)=E_tra(P_j)-R_sys(P_j) (5)

In Fig. 1, step 4 is described, and compares P_jUnder transmission of electricity risk benefit, determine the approximation of economic electric transmission power P_sim：

P_sim=P_k, and Y_dea(P_k)=max { Y_dea(P_j) (k 1～M-1 of ∈, j=1～M-1) (6)

In Fig. 1, step 5 is described, willInterval is divided into M ' equal portions, Obtain different section transmitted powers between the interval boundj =1～M ' -1；Different transmitted power values P are asked for respectively_j' under transmission of electricity risk benefit Y_dea(P_j′).Y is asked for here_dea(P_j′) Method and step 3) identical, simply in each correlation formula transmitted power difference (will P_jReplace with P_j′).WhenWhen being integer, WhenWhen being not integer, M ' values be more thanSmallest positive integral, wherein ε_PFor computational accuracy, its concrete numerical value is determined according to management and running demand, typically may be used Take 50MW≤ε_P≤200MW.

In step 3 and step 5, for risk benefit of transmitting electricity under different transmitted power values, can adopt and press transmitted power Parallel computation is improving computational efficiency.

In Fig. 1, step 6 is described, each P of comparison_j' under transmission of electricity risk benefit, determine the economic electric transmission work(of transmission cross-section Rate P_opt：

P_opt=P_k', and Y_dea(P_k')=max { Y_dea(P_j') (k ∈ 1～M ' -1, j=1～M ' -1) (7)

Although the present invention is disclosed as above with preferred embodiment, embodiment is not for limiting the present invention's.Not Depart from the spirit and scope of the present invention, any equivalence changes that is done or retouching also belong to the protection domain of the present invention.Cause The content that this protection scope of the present invention should be defined with claims hereof is as standard.

Claims (5)

1. a kind of transmission cross-section economic electric transmission power based on risk analyses determines method online, it is characterised in that including as follows Step：

1) power grid regulation center obtain online grid equipment model and parameter, current operating condition, transmission cross-section examination pre- Think fault set and its probability of happening, transmitted power upper limit P of transmission cross-section_maxWith lower limit P_min；

2) by the transmitted power of transmission cross-section in its lower limit P_minWith upper limit P_maxBetween be divided into M equal portions, obtain between bound Different transmitted power P_j：

$P_j=P_{min}+\frac{P_{max}-P_{min}}{M}\×j---\left(1\right)$

Wherein, j=1～M-1；

3) different transmitted power P are asked for respectively_jUnder transmission of electricity risk benefit Y_dea(P_j)；

4) each P of comparison_jUnder transmission of electricity risk benefit, determine approximation P of economic electric transmission power_sim：

P_sim=P_k, and Y_dea(P_k)=max { Y_dea(P_j)} (2)

Wherein, 1～M-1 of k ∈, j=1～M-1；

5) willInterval is divided into M ' equal portions, obtain between the interval bound it Between different section transmitted powerJ=1～M ' -1；Difference is asked for respectively Transmitted power value P '_jUnder transmission of electricity risk benefit Y_dea(P′_j)；

6) each P ' of comparison_jUnder transmission of electricity risk benefit, determine the economic electric transmission power P of transmission cross-section_opt：

P_opt=P '_k, and Y_dea(P′_k)=max { Y_dea(P′_j)} (3)

Wherein, k ∈ 1～M ' -1, j=1～M ' -1.

2. the transmission cross-section economic electric transmission power based on risk analyses according to claim 1 determines method online, and which is special Levy and be, the step 1) in, transmitted power upper limit P_maxTransmission cross-section equipment heat is obtained and is had contemplated that from power grid regulation department The constraint of stable and insulating requirements, transmitted power lower limit P_minDetermined according to scheduling requirement, P if without scheduling requirement_minValue It is zero.

3. the transmission cross-section economic electric transmission power based on risk analyses according to claim 1 determines method online, and which is special Levy and be, the step 3) or step 5) in transmission of electricity risk benefit ask for specifically include following steps：

3-1) in the giving of transmission cross-section, receiving end is scaled generator output and payload so that section of interest defeated Electrical power is P_jOr P '_j；

3-2) in line computation transmission cross-section transmitted power P_jOr P '_jUnder the emergent control measure that optimizes under each forecast failure；

3-3) transmitted power P is asked for by formula (4)_jOr P '_jEconomic benefit E of lower transmission of electricity_tra(P_j) or E_tra(P′_j)：

$\begin{array}{c}{E}_{tra}\left(P_j\right)=P_j\×T_{obv}\×C_{uit}\\ E_{tra}\left(P_j^{\′}\right)=P_j^{\′}\×T_{obv}\×C_{uit}\end{array}---\left(4\right)$

In formula, T_obvIt is the time cycle in line computation transmission of electricity risk benefit；C_uitFor the economic benefit that unit conveys electric energy；

3-4) transmitted power P is asked for by formula (5)_jOr P '_jUnder system unstability risk R_sys(P_j) or R_sys(P′_j)：

$\begin{array}{c}{R}_{sys}\left(P_j\right)=\underset{i=1}{\overset{N}{\Σ}}\[P_r\left(i\right)\×J\left(i\right)\]\\ R_{sys}\left(P_j^{\′}\right)=\underset{i=1}{\overset{N}{\Σ}}\[P_r\left(i\right)\×J\left(i\right)\]\end{array}---\left(5\right)$

In formula (5), N is the forecast failure number of transmission cross-section examination；P_r(i) be failure i in time T_obvInterior probability of happening；J(i) For making system keep total cost of stable emergent control measure under failure i, according to step 3-2) obtained by emergent control arrange Apply and calculated, method is as follows：

$\begin{array}{c}J\left(i\right)=\underset{k_1=1}{\overset{K_g}{\Σ}}\[{\mathrm{\ΔP}}_g(i,k_1)\·C_g\left(k_1\right)\·T_g(i,k_1)+C_{g-rst}\left(k_1\right)\]\\ +\underset{k_2=1}{\overset{K_l}{\Σ}}\[{\mathrm{\ΔP}}_l(i,k_2)\·C_l\left(k_2\right)\·T_l(i,k_2)\]\end{array}---\left(6\right)$

In formula (6), K_gMachine number is cut for emergent control under failure i；ΔP_g(i,k₁) it is kth under failure i₁Individual cut machine measure cut machine Amount；C_g(k₁) it is kth₁The individual loss cost for cutting machine measure unit of electrical energy；T_g(i,k₁) it is kth under failure i₁Individual cut unit is in event Barrier recovers to the required time estimated value of bringing normally into operation after eliminating；C_g-rst(k₁) it is kth₁Individual cut unit recovers the cost that puts into operation；K_l Count for emergent control cutting load under failure i；ΔP_l(i,k₂) it is kth under failure i₂The cutting load amount of individual cutting load point；C_l(k₂) For kth₂Individual cutting load unit of electrical energy loss；T_l(i,k₂) it is kth under failure i₂Individual cutting load point recovers to be taken to normal power supply Between；

3-5) transmitted power P is asked for by formula (7)_jOr P '_jUnder transmission of electricity risk benefit Y_dea(P_j) or Y_dea(P′_j)：

$\begin{array}{c}{Y}_{dea}\left(P_j\right)=E_{tra}\left(P_j\right)-R_{sys}\left(P_j\right)\\ Y_{dea}\left(P_j^{\′}\right)=E_{tra}\left(P_j^{\′}\right)-R_{sys}\left(P_j^{\′}\right)\end{array}---\left(7\right).$

4. the transmission cross-section economic electric transmission power based on risk analyses according to claim 1 determines method online, and which is special Levy and be, M=N_C+ 1, N_CFor computer check figure；WhenWhen being integer, WhenWhen being not integer, M ' values be more thanSmallest positive integral, wherein ε_PFor computational accuracy.

5. the transmission cross-section economic electric transmission power based on risk analyses according to claim 4 determines method online, and which is special Levy and be, the step 3) and step 5) in, for risk benefit of transmitting electricity under different transmitted power values, adopt and press transmitted power simultaneously Row calculating is improving computational efficiency.