CN103514364B - The grid equipment overload aid decision computational methods of meter and load transfer measure - Google Patents

Abstract

The invention discloses the grid equipment overload aid decision computational methods of a kind of meter and load transfer measure, belong to technical field of power system operation control.The present invention, according to the state of equipment, determines load transfer candidate's measure collection；Use DC power flow to calculate the performance indications of candidate's measure, the implementation result of performance preferably candidate's measure is checked, and determine the solution generator of overload problem, the maximum adjustment amount of load active power adjustment measure on this basis；Then, form generator, load adjustment scheme according to the computational accuracy of active power adjustment, obtain numerical procedure, determine final aid decision measure according to the check result of each scheme.The present invention adds active power adjustment measure on the basis of load transfer measure, reduce generator adjustment amount and pressure load, carry out AC power flow check by parallel computation, it is to avoid take turns iteration more, improve economy and the calculating speed of overload aid decision of aid decision measure.

Description

The grid equipment overload aid decision computational methods of meter and load transfer measure

Technical field

The invention belongs to technical field of power system operation control, more precisely, the present invention relates to a kind of suitable Based on by and load transfer measure grid equipment overload aid decision computational methods.

Background technology

It is known that overload aid decision is the critical function that electrical power system on-line safety and stability is analyzed.Work as electricity When overload problem occurring under net current state and forecast failure, by overload aid decision, it is possible in line computation Generator, load active power adjustment measure.

Comparing active power adjustment measure, load transfer controlling measurement cost is less, simple to operate, regulates the speed fast. Throwing according to circuit and transformer stops state, inspecting state and the running status of adjacent factory station equipment, permissible ONLINE RECOGNITION load transfer candidate's measure collection.If putting into operation, a circuit or a transformer cannot solve overload and ask Topic, then determine the active power adjustment amount being fully solved overload problem.Therefore, it is contemplated that pass through meter and load Turn and reduce generator adjustment amount and pressure load for measure, improve the economy of overload aid decision measure.

Summary of the invention

It is an object of the invention to: according to the running status of equipment, ONLINE RECOGNITION load transfer candidate's measure collection, Can turn for adding active power adjustment measure on the basis of load by the equipment of putting into operation, reducing generator adjustment amount and pressure is negative Lotus amount, improves the economy of overload aid decision measure.

Specifically, the present invention is to use following technical scheme to realize, and comprises the following steps:

1) by overload nargin under electrical network current state less than setting threshold value η_cr.1Equipment and forecast failure Lower overload nargin is less than setting threshold value η_cr.1Equipment join overload prevention device concentrate, by under forecast failure Apparatus overload margin of safety minimum of a value is less than setting threshold value η_cr.2Forecast failure join critical failure concentrate, If overload prevention device is concentrated with overload prevention device, then enter step 2)；Otherwise, method ends；

Described equipment refers to circuit and transformer；

2) if the switch tool group that Guan Bi and the equipment being in stoppage in transit and maintenance done state are joined directly together just can Equipment investment is run, and the joint that the node that is joined directly together of this equipment is joined directly together with overload prevention device concentrating equipment Point belongs to same electrical island, then this equipment adds the equipment that can put into operation and concentrates, if can be concentrated with by the equipment of putting into operation Can be put into operation equipment, then enter step 3)；Otherwise, step 6) is entered；

3) it is respectively directed to concentrate each equipment that can put into operation by the equipment of putting into operation, uses DC power flow estimation to put into operation and set Concentrate the overload nargin of each equipment for overload prevention device after putting into operation, and calculate the comprehensive of equipment that can put into operation Energy index, if overload prevention device concentrates the overload nargin of all devices to be all higher than specifying threshold value η_thres.on, Then enter step 4)；Otherwise enter step 5)；

Described η_thres.on＞ η_cr.1；

4) after using AC power flow to calculate putting equipment in service, overload prevention device concentrates the overload nargin of each equipment, And calculate the integrated performance index of equipment of can putting into operation, if overload prevention device is concentrated there is overload nargin less than η_cr.1 Equipment, then enter step 5)；Otherwise, using put into operation equipment maximum for integrated performance index as final control Measure processed method ends；

5) choose integrated performance index to set as to be checked putting into operation more than the put into operation equipment of given threshold value Standby, enter step 6)；

6) if there is put into operation equipment to be checked, the base for load is turned at each equipment measure that puts into operation the most respectively The solution generator of overload problem, the maximum adjustment amount of load active power adjustment measure is determined, the most directly on plinth Determine the solution generator of overload problem, the maximum adjustment amount of load active power adjustment measure；

7) according to generator, the maximum adjustment amount of load active power adjustment measure and the computational accuracy shape of active power adjustment Becoming generator, load adjustment scheme, if there is put into operation equipment to be checked, then to be checked being put into operation Equipment and generator, the combination of load adjustment scheme obtain the numerical procedure needing AC power flow to check, the most directly Connect generator, load adjustment scheme as the numerical procedure needing AC power flow to check, according to control measure Control cost ascending order numerical procedure is ranked up, by parallel computation, each scheme is carried out AC power flow for fault-free and critical failure collection is checked, if obtaining overload nargin more than η_cr.1Calculating Scheme, then terminate parallel computation, using this numerical procedure as the output of final control measure method ends； Otherwise, method ends.

Being further characterized by described step 1) of technique scheme uses different limit values to calculate electrical network With the overload nargin of jth equipment under forecast failure under current state:

When jth equipment is circuit, by formula (1) computation overload margin of safety η_j:

${\mathrm{\η}}_j=(1-\frac{I_L}{I_P})\×100\%---\left(1\right)$

Wherein, when calculating the overload nargin of circuit under electrical network current state, I_LFor circuit under current state The electric current of the bigger one end of two ends electric current, I_PElectric current is allowed for circuit under normal running (operation) conditions；When calculating, electrical network is pre- When thinking the overload nargin of circuit under fault, I_LFor the electric current of the bigger one end of circuit two ends electric current under forecast failure, I_PRun for circuit under emergency conditions and allow electric current；

When jth equipment is transformer, pacified by the overload of formula (2) each winding of calculating transformer respectively Full nargin η_j,w, the overload nargin of this transformer equipment is overload nargin in each winding of this transformer Minimum of a value:

${\mathrm{\η}}_{j,w}=(1-\frac{S_T/U_T}{S_P/U_{N,w}})\×100\%---\left(2\right)$

Wherein, the different windings of w indication transformer, U_N,wRated voltage for each winding；Work as when calculating electrical network Under front state during the overload nargin of transformer, S_TAnd U_TFor the apparent energy under winding current state and electricity Pressure, S_PFor the permission capacity of transformer under normal condition；When calculating the overload of transformer under electrical network forecast failure During margin of safety, S_TAnd U_TFor the apparent energy of winding under forecast failure and voltage, S_PFor becoming under emergency conditions The permission capacity of depressor.

Being further characterized by described step 3) and step 4) by formula (3) of technique scheme Calculating can put into operation the integrated performance index of equipment:

$p_{i_L}=\underset{j=1}{\overset{N}{\mathrm{\Σ}}}\left[S_{i_L,j}(1-{\mathrm{\η}}_j)\right]+\underset{k=1}{\overset{W}{\mathrm{\Σ}}}\underset{j_1=1}{\overset{N_k}{\mathrm{\Σ}}}\left[S_{i_L,j_1.k}(1-{\mathrm{\η}}_{j_1.k})\right]---\left(3\right)$

Wherein, i_L=1,2 ..., L, L are the sum of equipment of can putting into operation,It is i-th_LThe individual equipment that puts into operation comprehensive Performance indications, N is the sum of overload prevention device, η under current state_jOverload for jth overload prevention device is abundant Degree,It is i-th_LThe overload nargin variable quantity of jth overload prevention device after the individual putting equipment in service that puts into operation；W For the sum of overload critical failure, N_kFor the sum of overload prevention device under kth overload critical failure,For jth under kth overload critical failure₁The overload nargin of individual overload prevention device,It is i_LJth under kth overload critical failure after the individual putting equipment in service that puts into operation₁Individual overload prevention device overload nargin Variable quantity.

Being further characterized by described step 6) of technique scheme determines the generating solving overload problem Machine, the step of maximum adjustment amount of load active power adjustment measure are divided into four steps:

, if there is put into operation equipment to be checked, then according to the apparatus overload safety after putting equipment in service in the first step Nargin calculates active power adjustment measure by formula (4) and combines overload under overload under current state and forecast failure Close performance indications；Otherwise, directly by formula (4) calculate active power adjustment measure under current state overload and The integrated performance index of overload under forecast failure:

$w_{i_M}=\underset{j=1}{\overset{N}{\mathrm{\Σ}}}\left[{\mathrm{\λ}}_{i_M,j}(1-{\mathrm{\η}}_j)\right]+\underset{k=1}{\overset{W}{\mathrm{\Σ}}}\underset{j_1=1}{\overset{N_k}{\mathrm{\Σ}}}\left[{\mathrm{\λ}}_{i_M,j_1.k}(1-{\mathrm{\η}}_{j_1.k})\right]---\left(4\right)$

Wherein, i_M=1,2 ..., M, M are the sum of active power adjustment measure,It is i-th_MIndividual active power adjustment measure Integrated performance index, N is the sum of overload prevention device, η under current state_jOverload for jth overload prevention device Margin of safety,It is i-th_MThe individual active power adjustment measure active po wer sensitivity to jth overload prevention device；W was Carry the sum of safety-critical fault, N_kFor the sum of overload prevention device under kth overload critical failure, For jth under kth overload critical failure₁The overload nargin of individual overload prevention device,It is i-th_MIndividual Active power adjustment measure is to jth under kth fault₁The active po wer sensitivity of individual equipment；

Second step, is more than the active power adjustment measure alternately measure setting threshold value by integrated performance index, Choose integrated performance index be negative alternative measure as power transmission queue, the generator node in queue is exerted oneself increasing Add and the meritorious reduction of load bus；Choosing integrated performance index is that positive alternative measure is as by electricity queue, team Generator node in row is exerted oneself reduction；

3rd step, is first according to the priority of control measure order from high to low to power transmission queue with by electricity team Alternative measure in row is ranked up, then to controlling the identical alternative measure of priority by cost performance index by greatly Being ranked up to little order, cost performance index is calculated by formula (5):

$G_{i_M}=\left|w_{i_M}\right|/C_{i_M}---\left(5\right)$

Wherein,It is i-th_MThe Readjusting cost of individual active power adjustment measure unit power；

4th step, makees the maximum adjustment amount of power transmission queue with the maximum in the maximum adjustment amount by electricity queue For determining the maximum adjustment amount of numerical procedure.

Being further characterized by described step 7) of technique scheme, for different adjustment amount requirements, By the adjustment order of the control measure determined in step 6), it is sequentially adjusted in power transmission queue and each joint by electricity queue Point so that control Least-cost and cause system frequency deviation to meet due to the active power imbalance of system Service requirement, obtains numerical procedure.

Beneficial effects of the present invention is as follows: the present invention can ONLINE RECOGNITION load transfer candidate's measure collection, negative Lotus turns for adding active power adjustment measure on the basis of measure, reduces generator adjustment amount and pressure load；According to having The computational accuracy that merit adjusts forms generator, load adjustment scheme, carries out AC power flow school by parallel computation Core, it is to avoid take turns iteration more.Therefore, the present invention proposes meter and the grid equipment overload of load transfer measure are auxiliary Help decision-making computational methods can improve economy and the calculating speed of overload aid decision of aid decision measure.

Accompanying drawing explanation

Fig. 1 is the flow chart of the inventive method.

Detailed description of the invention

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

What in Fig. 1, step 1 described is less than setting threshold value η by electrical network current state overload nargin_cr.1's Under equipment and forecast failure, overload nargin is less than setting threshold value η_cr.1Equipment join overload prevention device collection In, by equipment overload nargin minimum of a value under forecast failure less than setting threshold value η_cr.2Forecast failure add Concentrate to critical failure, if overload prevention device is concentrated with overload prevention device, then enter step 2)；Otherwise, this is terminated Method.Described equipment refers to circuit and transformer.Overload nargin threshold value η_cr.1, it is used for determining that electrical network is worked as Overload prevention device under front state and forecast failure；Overload nargin threshold value η_cr.2, it is used for determining that participation calculates The forecast failure of aid decision measure integrated performance index.

Different limit values is used to calculate the overload of jth equipment under electrical network current state and forecast failure abundant Degree: when jth equipment is circuit, by formula (1) computation overload margin of safety η_j:

${\mathrm{\η}}_j=(1-\frac{I_L}{I_P})\×100\%---\left(1\right)$

Wherein, when calculating the overload nargin of circuit under electrical network current state, I_LFor circuit under current state The electric current of the bigger one end of two ends electric current, I_PElectric current is allowed for circuit under normal running (operation) conditions；When calculating, electrical network is pre- When thinking the overload nargin of circuit under fault, I_LFor the electric current of the bigger one end of circuit two ends electric current under forecast failure, I_PRun for circuit under emergency conditions and allow electric current；

When jth equipment is transformer, pacified by the overload of formula (2) each winding of calculating transformer respectively Full nargin η_j,w, the overload nargin of this transformer equipment is overload nargin in each winding of this transformer Minimum of a value:

${\mathrm{\η}}_{j,w}=(1-\frac{S_T/U_T}{S_P/U_{N,w}})\×100\%---\left(2\right)$

Wherein, the different windings of w indication transformer, U_N,wRated voltage for each winding；Work as when calculating electrical network Under front state during the overload nargin of transformer, S_TAnd U_TFor the apparent energy under winding current state and electricity Pressure, S_PFor the permission capacity of transformer under normal condition；When calculating the overload of transformer under electrical network forecast failure During margin of safety, S_TAnd U_TFor the apparent energy of winding under forecast failure and voltage, S_PFor becoming under emergency conditions The permission capacity of depressor.

If what in Fig. 1, step 2 described is to close to be joined directly together with the equipment being in stoppage in transit and maintenance done state Switch tool group just equipment investment can be run, and the node that is joined directly together of this equipment and overload prevention device collection The node that middle equipment is joined directly together belongs to same electrical island, then this equipment adds the equipment that can put into operation and concentrates, If the equipment that can put into operation can be concentrated with the equipment of putting into operation, then enter step 3)；Otherwise, step 6) is entered.

What in Fig. 1, step 3 described is to be respectively directed to concentrate each equipment that can put into operation by the equipment of putting into operation, and uses straight Flow overload prevention device after trend estimates the putting equipment in service that can put into operation and concentrate the overload nargin of each equipment, and calculate Can be put into operation the integrated performance index of equipment, if the overload nargin that overload prevention device concentrates all devices is all higher than Specify threshold value η_thres.on, wherein η_thres.on＞ η_cr.1, then step 4) is entered；Otherwise, step 5) is entered.Cross Carry margin of safety threshold value η_thres.on, for determining the put into operation equipment that overload can be completely eliminated.

The equipment that can put into operation is calculated comprehensive to transship under overload under current state and forecast failure by formula (3) Performance indications:

$p_{i_L}=\underset{j=1}{\overset{N}{\mathrm{\Σ}}}\left[S_{i_L,j}(1-{\mathrm{\η}}_j)\right]+\underset{k=1}{\overset{W}{\mathrm{\Σ}}}\underset{j_1=1}{\overset{N_k}{\mathrm{\Σ}}}\left[S_{i_L,j_1.k}(1-{\mathrm{\η}}_{j_1.k})\right]---\left(3\right)$

Wherein, i_L=1,2 ..., L, L are the sum of equipment of can putting into operation,It is i-th_LThe individual equipment that puts into operation comprehensive Performance indications, N is the sum of overload prevention device, η under current state_jOverload for jth overload prevention device is abundant Degree,It is i-th_LThe overload nargin variable quantity of jth overload prevention device after the individual putting equipment in service that puts into operation；W For the sum of overload critical failure, N_kFor the sum of overload prevention device under kth overload critical failure,For jth under kth overload critical failure₁The overload nargin of individual overload prevention device,It is i_LJth under kth overload critical failure after the individual putting equipment in service that puts into operation₁Individual overload prevention device overload nargin Variable quantity.

What in Fig. 1, step 4 described is that after using AC power flow to calculate putting equipment in service, overload prevention device concentrates each to set Standby overload nargin, and calculate the integrated performance index of the equipment that can put into operation, exist if overload prevention device is concentrated Overload nargin is less than η_cr.1Equipment, then enter step 5)；Otherwise, can by maximum for integrated performance index The equipment that puts into operation is as final control measure method ends.

What in Fig. 1, step 5 described is to choose the integrated performance index equipment more than given threshold value as treating school The put into operation equipment of core, enters step 6).

If what in Fig. 1, step 6 described is to there is put into operation equipment to be checked, set each putting into operation the most respectively Standby measure turns for determining the solution generator of overload problem, load active power adjustment measure on the basis of load Big adjustment amount, the most directly determines the maximum tune solving the generator of overload problem, load active power adjustment measure Whole amount.Determine that the step of the maximum adjustment amount solving the generator of overload problem, load active power adjustment measure is divided It is four steps:

, if there is put into operation equipment to be checked, then according to the apparatus overload safety after putting equipment in service in the first step Nargin calculates active power adjustment measure by formula (4) and combines overload under overload under current state and forecast failure Close performance indications；Otherwise, directly by formula (4) calculate active power adjustment measure under current state overload and The integrated performance index of overload under forecast failure:

$w_{i_M}=\underset{j=1}{\overset{N}{\mathrm{\Σ}}}\left[{\mathrm{\λ}}_{i_M,j}(1-{\mathrm{\η}}_j)\right]+\underset{k=1}{\overset{W}{\mathrm{\Σ}}}\underset{j_1=1}{\overset{N_k}{\mathrm{\Σ}}}\left[{\mathrm{\λ}}_{i_M,j_1.k}(1-{\mathrm{\η}}_{j_1.k})\right]---\left(4\right)$

Wherein, i_M=1,2 ..., M, M are the sum of active power adjustment measure,It is i-th_MIndividual active power adjustment measure Integrated performance index, N is the sum of overload prevention device, η under current state_jOverload for jth overload prevention device Margin of safety,It is i-th_MThe individual active power adjustment measure active po wer sensitivity to jth overload prevention device；W was Carry the sum of safety-critical fault, N_kFor the sum of overload prevention device under kth overload critical failure, For jth under kth overload critical failure₁The overload nargin of individual overload prevention device,It is i-th_MIndividual Active power adjustment measure is to jth under kth fault₁The active po wer sensitivity of individual equipment.

Second step, is more than the active power adjustment measure alternately measure setting threshold value by integrated performance index, Choose integrated performance index be negative alternative measure as power transmission queue, the generator node in queue is exerted oneself increasing Add and the meritorious reduction of load bus；Choosing integrated performance index is that positive alternative measure is as by electricity queue, team Generator node in row is exerted oneself reduction.

3rd step, is first according to the priority of control measure order from high to low to power transmission queue with by electricity team Alternative measure in row is ranked up, then to controlling the identical alternative measure of priority by cost performance index by greatly It is ranked up to little order, by formula (5) calculating cost performance index:

$G_{i_M}=\left|w_{i_M}\right|/C_{i_M}---\left(5\right)$

Wherein,It is i-th_MThe Readjusting cost of individual active power adjustment measure unit power.

4th step, makees the maximum adjustment amount of power transmission queue with the maximum in the maximum adjustment amount by electricity queue For determining the maximum adjustment amount of numerical procedure.

What in Fig. 1, step 7 described is according to generator, the maximum adjustment amount of load active power adjustment measure and to have The computational accuracy that merit adjusts forms generator, load adjustment scheme, if there is put into operation equipment to be checked, Then obtain needing AC power flow to check with generator, the combination of load adjustment scheme by put into operation equipment to be checked Numerical procedure, otherwise directly using generator, load adjustment scheme as the calculating needing AC power flow to check Scheme, is ranked up numerical procedure according to the order that the control cost of control measure is ascending, by also Row calculates and carries out each scheme checking for the AC power flow of fault-free and critical failure collection, if obtaining overload peace Full nargin is more than η_cr.1Numerical procedure, then terminate parallel computation, using this numerical procedure as final control measure Output method ends；Otherwise, method ends

For different adjustment amount requirements, by the adjustment order of the control measure determined in step 6), adjust successively Whole power transmission queue and by electricity queue each node so that control Least-cost and due to system active power not Balance and cause system frequency deviation to meet service requirement, obtain numerical procedure.

Although the present invention is open as above with preferred embodiment, but embodiment is not for limiting the present invention's. Without departing from the spirit and scope of the invention, any equivalence change done or retouching, also belong to this Bright protection domain.Therefore the content that protection scope of the present invention should be defined with claims hereof For standard.

Claims (4)

1. the grid equipment overload aid decision computational methods of meter and load transfer measure, it is characterised in that bag Include following steps:

1) by overload nargin under electrical network current state less than setting threshold value η_cr.1Equipment and forecast failure Lower overload nargin is less than setting threshold value η_cr.1Equipment join overload prevention device concentrate, by under forecast failure Apparatus overload margin of safety minimum of a value is less than setting threshold value η_cr.2Forecast failure join critical failure concentrate, If overload prevention device is concentrated with overload prevention device, then enter step 2)；Otherwise, method ends；

Described equipment refers to circuit and transformer；

2) if the switch tool group that Guan Bi and the equipment being in stoppage in transit and maintenance done state are joined directly together just can Equipment investment is run, and the joint that the node that is joined directly together of this equipment is joined directly together with overload prevention device concentrating equipment Point belongs to same electrical island, then this equipment adds the equipment that can put into operation and concentrates, if can be concentrated with by the equipment of putting into operation Can be put into operation equipment, then enter step 3)；Otherwise, step 6 is entered)；

3) it is respectively directed to concentrate each equipment that can put into operation by the equipment of putting into operation, uses DC power flow estimation to put into operation and set Concentrate the overload nargin of each equipment for overload prevention device after putting into operation, and calculate the comprehensive of equipment that can put into operation Energy index, if overload prevention device concentrates the overload nargin of all devices to be all higher than specifying threshold value η_thres.on, Then enter step 4)；Otherwise enter step 5)；

Described η_thres.on＞ η_cr.1；

The integrated performance index of equipment of can putting into operation is calculated by formula (3):

$p_{i_L}=\underset{j=1}{\overset{N}{\Σ}}\[S_{i_L,j}(1-{\mathrm{\η}}_j)\]+\underset{k=1}{\overset{W}{\Σ}}\underset{j_1=1}{\overset{N_k}{\Σ}}\[S_{i_L,j_1.k}(1-{\mathrm{\η}}_{j_1.k})\]---\left(3\right)$

Wherein, i_L=1,2 ..., L, L are the sum of equipment of can putting into operation,It is i-th_LCombining of the individual equipment that puts into operation Closing performance indications, N is the sum of overload prevention device, η under current state_jOverload for jth overload prevention device Nargin,It is i-th_LThe overload nargin variable quantity of jth overload prevention device after the individual putting equipment in service that puts into operation； W is the sum of overload critical failure, N_kFor overload prevention device total under kth overload critical failure Number,For jth under kth overload critical failure₁The overload nargin of individual overload prevention device,For I-th_LJth under kth overload critical failure after the individual putting equipment in service that puts into operation₁Individual overload prevention device overload is abundant Degree variable quantity；

4) after using AC power flow to calculate putting equipment in service, overload prevention device concentrates the overload nargin of each equipment, And the integrated performance index of the equipment that can be put into operation by formula (3) calculating, if overload prevention device is concentrated there is overload peace Full nargin is less than η_cr.1Equipment, then enter step 5)；Otherwise, maximum the putting into operation of integrated performance index is set Standby as final control measure method ends；

5) choose integrated performance index to set as to be checked putting into operation more than the put into operation equipment of given threshold value Standby, enter step 6)；

6) if there is put into operation equipment to be checked, the base for load is turned at each equipment measure that puts into operation the most respectively The solution generator of overload problem, the maximum adjustment amount of load active power adjustment measure is determined, the most directly on plinth Determine the solution generator of overload problem, the maximum adjustment amount of load active power adjustment measure；

7) according to generator, the maximum adjustment amount of load active power adjustment measure and the computational accuracy shape of active power adjustment Becoming generator, load adjustment scheme, if there is put into operation equipment to be checked, then to be checked being put into operation Equipment and generator, the combination of load adjustment scheme obtain the numerical procedure needing AC power flow to check, the most directly Connect generator, load adjustment scheme as the numerical procedure needing AC power flow to check, according to control measure Control cost ascending order numerical procedure is ranked up, by parallel computation, each scheme is carried out AC power flow for fault-free and critical failure collection is checked, if obtaining overload nargin more than η_cr.1Calculating Scheme, then terminate parallel computation, using this numerical procedure as the output of final control measure method ends； Otherwise, method ends.

The grid equipment overload aid decision of meter the most according to claim 1 and load transfer measure calculates Method, it is characterised in that described step 1) in use different limit value to calculate under electrical network current state and anticipation The overload nargin of jth equipment under fault:

When jth equipment is circuit, by formula (1) computation overload margin of safety η_j:

${\mathrm{\η}}_j=(1-\frac{I_L}{I_P})\×100\%---\left(1\right)$

Wherein, when calculating the overload nargin of circuit under electrical network current state, I_LFor circuit under current state The electric current of the bigger one end of two ends electric current, I_PElectric current is allowed for circuit under normal running (operation) conditions；When calculating, electrical network is pre- When thinking the overload nargin of circuit under fault, I_LFor the electric current of the bigger one end of circuit two ends electric current under forecast failure, I_PRun for circuit under emergency conditions and allow electric current；

When jth equipment is transformer, pacified by the overload of formula (2) each winding of calculating transformer respectively Full nargin η_j,w, the overload nargin of this transformer equipment is overload nargin in each winding of this transformer Minimum of a value:

${\mathrm{\η}}_{j,w}=(1-\frac{S_T/U_T}{S_P/U_{N,w}})\×100\%---\left(2\right)$

Wherein, the different windings of w indication transformer, U_N,wRated voltage for each winding；Work as when calculating electrical network Under front state during the overload nargin of transformer, S_TAnd U_TFor the apparent energy under winding current state and electricity Pressure, S_PFor the permission capacity of transformer under normal condition；When calculating the overload of transformer under electrical network forecast failure During margin of safety, S_TAnd U_TFor the apparent energy of winding under forecast failure and voltage, S_PFor becoming under emergency conditions The permission capacity of depressor.

The grid equipment overload aid decision of meter the most according to claim 1 and load transfer measure calculates Method, it is characterised in that described step 6) in determine solution the generator of overload problem, load active power adjustment The step of the maximum adjustment amount of measure is divided into four steps:

, if there is put into operation equipment to be checked, then according to the apparatus overload safety after putting equipment in service in the first step Nargin calculates active power adjustment measure by formula (4) and combines overload under overload under current state and forecast failure Close performance indications；Otherwise, directly by formula (4) calculate active power adjustment measure under current state overload and The integrated performance index of overload under forecast failure:

$w_{i_M}=\underset{j=1}{\overset{N}{\Σ}}\[{\mathrm{\λ}}_{i_M,j}(1-{\mathrm{\η}}_j)\]+\underset{k=1}{\overset{W}{\Σ}}\underset{j_1=1}{\overset{N_k}{\Σ}}\[{\mathrm{\λ}}_{i_M,j_1.k}(1-{\mathrm{\η}}_{j_1.k})\]---\left(4\right)$

Wherein, i_M=1,2 ..., M, M are the sum of active power adjustment measure,It is i-th_MIndividual active power adjustment measure Integrated performance index, N is the sum of overload prevention device, η under current state_jOverload for jth overload prevention device Margin of safety,It is i-th_MThe individual active power adjustment measure active po wer sensitivity to jth overload prevention device；W was Carry the sum of safety-critical fault, N_kFor the sum of overload prevention device under kth overload critical failure, For jth under kth overload critical failure₁The overload nargin of individual overload prevention device,It is i-th_MIndividual Active power adjustment measure is to jth under kth fault₁The active po wer sensitivity of individual equipment；

Second step, is more than the active power adjustment measure alternately measure setting threshold value by integrated performance index, Choose integrated performance index be negative alternative measure as power transmission queue, the generator node in queue is exerted oneself increasing Add and the meritorious reduction of load bus；Choosing integrated performance index is that positive alternative measure is as by electricity queue, team Generator node in row is exerted oneself reduction；

3rd step, is first according to the priority of control measure order from high to low to power transmission queue with by electricity team Alternative measure in row is ranked up, then to controlling the identical alternative measure of priority by cost performance index by greatly Being ranked up to little order, cost performance index is calculated by formula (5):

$G_{i_M}=\left|w_{i_M}\right|/C_{i_M}---\left(5\right)$

Wherein,It is i-th_MThe Readjusting cost of individual active power adjustment measure unit power；

4th step, makees the maximum adjustment amount of power transmission queue with the maximum in the maximum adjustment amount by electricity queue For determining the maximum adjustment amount of numerical procedure.

The grid equipment overload aid decision of meter the most according to claim 1 and load transfer measure calculates Method, it is characterised in that described step 7) in, for different adjustment amount requirements, by step 6) in really The adjustment order of fixed control measure, is sequentially adjusted in power transmission queue and each node by electricity queue so that control Least-cost and owing to the active power of system is uneven and cause system frequency deviation to meet service requirement, To numerical procedure.