CN108233369B - Active power distribution network load capacity safety assessment method under expected accident condition - Google Patents

Active power distribution network load capacity safety assessment method under expected accident condition Download PDF

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CN108233369B
CN108233369B CN201810090230.XA CN201810090230A CN108233369B CN 108233369 B CN108233369 B CN 108233369B CN 201810090230 A CN201810090230 A CN 201810090230A CN 108233369 B CN108233369 B CN 108233369B
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distribution network
node
active power
power distribution
formula
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CN108233369A (en
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陈永进
钟伟
吕国全
翁兴航
黄慧
郑广杰
胡烈良
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Shaoguan Power Supply Bureau Guangdong Power Grid Co Ltd
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Shaoguan Power Supply Bureau Guangdong Power Grid Co Ltd
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
    • G06Q10/00—Administration; Management
    • G06Q10/06—Resources, workflows, human or project management; Enterprise or organisation planning; Enterprise or organisation modelling
    • G06Q10/063—Operations research, analysis or management
    • G06Q10/0639—Performance analysis of employees; Performance analysis of enterprise or organisation operations
    • G06Q10/06393—Score-carding, benchmarking or key performance indicator [KPI] analysis
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J2203/00—Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
    • H02J2203/20—Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/003—Load forecast, e.g. methods or systems for forecasting future load demand

Abstract

The invention relates to the technical field of operation and control of an active power distribution network, in particular to a method for evaluating the load capacity safety of the active power distribution network under an expected accident condition. The method can consider various expected accident situations of the active power distribution network, and take account of the influence of the continuous reactive power compensation device, the discrete reactive power compensation device and the distributed power supply on the safety evaluation of the load capacity of the active power distribution network, so that the safety of the load capacity of the active power distribution network under the expected accident condition can be accurately evaluated, the defects of the traditional calculation method for the maximum power supply capacity of the power distribution network are overcome, and the safety evaluation problem of the load capacity of the active power distribution network under the expected accident condition can be accurately solved.

Description

Active power distribution network load capacity safety assessment method under expected accident condition
Technical Field
The invention relates to the technical field of operation and control of an active power distribution network, in particular to a safety assessment method for load capacity of the active power distribution network under an expected accident condition.
Background
The load capacity of the active power distribution network assigns the maximum load supply capacity of the power grid under various operation constraint conditions, and is a key index for evaluating the power supply safety operation degree of the power distribution network. In the traditional analysis of the load capacity of the power distribution network, the maximum load capacity of the power distribution network is calculated by considering only the interconnection capacity constraint among feeders, the main transformer capacity constraint and the load transfer path after the main transformer fault. Although the method is simple in calculation, the maximum load capacity of the power distribution network can be rapidly calculated. However, the actual maximum load capacity of the active power distribution network cannot be accurately calculated due to the lack of consideration of the power flow constraint, the node voltage constraint and the thermal stability constraint of the feeder, the lack of consideration of the tie switch between the section switch of the feeder and the feeder, and the lack of consideration of the situation that multiple power devices simultaneously fail.
Disclosure of Invention
The invention aims to overcome the defects of the prior art, provides a safety assessment method for the load capacity of an active power distribution network under the condition of an expected accident, and overcomes the defects of a traditional calculation method for the maximum power supply capacity of the power distribution network so as to accurately solve the safety assessment problem for the load capacity of the active power distribution network under the condition of the expected accident.
In order to solve the technical problems, the invention adopts the technical scheme that:
the method for safely evaluating the load capacity of the active power distribution network under the expected accident condition comprises the following steps:
s10, acquiring basic data of safety evaluation of the load capacity of the active power distribution network; the basic data comprise basic physical data and basic operation data, wherein the basic physical data comprise line resistance and reactance parameters, maximum current values allowed by a line, lower and upper reactive power limits of a continuous reactive power compensation device, single-group reactive power compensation capacity and maximum switching group number of a discrete reactive power compensation device, and maximum apparent power of a distributed power supply; the basic operation data comprise a lower bound and an upper bound of a node voltage amplitude value, basic state active power and reactive power of a load and an active power predicted value of a distributed power supply;
s20, determining an expected accident set of load capacity safety assessment of the active power distribution network based on the basic data in the step S10, wherein the expected accident set is selected from one or more combinations of single main transformer faults, multiple main transformer faults, single main transformer overhaul, multiple main transformer overhaul, single line faults, multiple line faults, single line overhaul and multiple line overhaul;
s30, establishing an active power distribution network load capacity safety assessment model under the condition of expected accidents based on the basic data acquired in the step S10 and the expected accident set determined in the step S20;
s40, performing convex processing on the model in the step S30, solving the model obtained after the convex processing, obtaining the load capacity of the active power distribution network, obtaining the maximum load capacity of the active power distribution network under different expected accident conditions, and evaluating the safety of the load capacity of the active power distribution network.
The method for evaluating the load capacity safety of the active power distribution network under the expected accident condition can consider various expected accident situations of the active power distribution network, and take account of the influence of the continuous reactive power compensation device, the discrete reactive power compensation device and the distributed power supply on the load capacity safety evaluation of the active power distribution network, so that the safety of the load capacity of the active power distribution network under the expected accident condition can be accurately evaluated, the defects of the traditional method for calculating the maximum power supply capacity of the power distribution network are overcome, and the problem of the safety evaluation of the load capacity of the active power distribution network under the expected accident condition can be accurately solved.
Preferably, in step S20, an expected accident is set
Figure BDA0001563477370000021
Determine the set of expected accidents
Figure BDA0001563477370000022
Preferably, the safety evaluation model for load capacity of the active distribution network under the expected accident condition in step S30 is performed according to the following steps:
s31, establishing a target function of the active power distribution network load capacity safety evaluation model under the expected accident condition by taking the maximum load capacity of the active power distribution network as a target, wherein the target function is shown as the following formula:
max λ (1)
in the formula (1), lambda is a load increase factor;
s32, determining active power distribution network node power balance constraint:
Figure BDA0001563477370000023
in formula (2):
Figure BDA0001563477370000024
and
Figure BDA0001563477370000025
respectively expected accident phisThe voltage amplitudes of nodes i and j under the condition; gijAnd BijConductance and susceptance, respectively, of the line (i, j);
Figure BDA0001563477370000026
to anticipate an accident phisVoltage phase angle difference of nodes i and j under the condition;
Figure BDA0001563477370000027
and
Figure BDA0001563477370000028
respectively expected accident phisThe active power of a generator, a load and a distributed power supply injection node i is generated under the condition;
Figure BDA0001563477370000029
and
Figure BDA00015634773700000210
respectively expected accident phisInjecting reactive power of a node i into the generator, the load, the distributed power supply, the continuous reactive power compensation device and the discrete reactive power compensation device under the condition; Θ (i) is a set of nodes connected to node i;
setting new variables
Figure BDA0001563477370000031
And
Figure BDA0001563477370000032
as follows:
Figure BDA0001563477370000033
the active distribution network node power balance constraint can be expressed as:
Figure BDA0001563477370000034
s33, determining node voltage amplitude constraint:
Figure BDA0001563477370000035
in formula (5): vi,minAnd Vi,maxRespectively a lower bound and an upper bound of the voltage amplitude of the node i;
s34, determining the current constraint of the line:
Figure BDA0001563477370000036
in formula (6):
Figure BDA0001563477370000037
and Iij,maxRespectively expected accident phisThe amplitude of the current through the line (i, j) under the conditions and its upper bound;
s35, determining operation constraint of the distribution transformer:
Figure BDA0001563477370000038
in the formula (7), the reaction mixture is,
Figure BDA0001563477370000039
is the maximum apparent power of the distribution transformer connected between the root node o and the node i of the substation;
s36, determining the operation constraint of the continuous reactive power compensation device:
Figure BDA00015634773700000310
formula (8)) The method comprises the following steps:
Figure BDA00015634773700000311
and
Figure BDA00015634773700000312
respectively expected accident phisReactive power of a continuous reactive power compensation device connected to the node i under the condition, and a lower bound and an upper bound of the reactive power;
s37, determining the operation constraint of the discrete reactive power compensation device:
Figure BDA0001563477370000041
in formula (9):
Figure BDA0001563477370000042
and
Figure BDA0001563477370000043
respectively expected accident phisReactive power and switching group number of the discrete reactive power compensation device connected to the node i under the condition;
Figure BDA0001563477370000044
and Wi DCRespectively switching the reactive power and the maximum switching group number when the discrete reactive power compensation device connected to the node i switches the single group capacity;
s38, determining the operation constraint of the distributed power supply:
Figure BDA0001563477370000045
in formula (10):
Figure BDA0001563477370000046
and
Figure BDA0001563477370000047
respectively a maximum active power predicted value and a maximum apparent power of a distributed power supply connected to a node iAt power;
Figure BDA0001563477370000048
to anticipate an accident phisA power factor angle of a distributed power supply conditionally connected at node i;
s39, determining radial grid structure constraint of the active power distribution network:
Figure BDA0001563477370000049
in formula (11): n is a node set except a root node of the transformer substation; NS is a set of substation root nodes; e is the set of the common line and the distribution transformer line; the first term of the above equation is used to determine whether the line is in the radial grid structure of the distribution network, for
Figure BDA00015634773700000410
Introducing two binary variables
Figure BDA00015634773700000411
And
Figure BDA00015634773700000412
if node j is the parent node of node i
Figure BDA00015634773700000413
Or node i is a parent node of node j
Figure BDA00015634773700000414
Then
Figure BDA00015634773700000415
At the moment, the lines (i, j) normally run in the radial distribution network frame; if it is not
Figure BDA00015634773700000416
And
Figure BDA00015634773700000417
then
Figure BDA00015634773700000418
At which point line (i, j) exits service.
Preferably, the constraint in equation (11) is used to limit each node to have only one parent node, and the constraint in equation (11) is used to limit the substation root node to have no parent node.
Preferably, step S40 is performed according to the following steps:
s41, converting the node power balance constraint of the active power distribution network into:
Figure BDA0001563477370000051
Figure BDA0001563477370000052
Figure BDA0001563477370000053
s42, converting the line current constraint into:
Figure BDA0001563477370000054
s43, converting the operation constraint of the distribution transformer into:
Figure BDA0001563477370000055
s44, expressing an objective function by using a formula (1), expressing node voltage amplitude constraint by using a formula (5), expressing continuous reactive power compensation device operation constraint by using a formula (8), expressing discrete reactive power compensation device operation constraint by using a formula (9), expressing distributed power supply operation constraint by using a formula (10), expressing active power distribution network radial grid constraint by using a formula (11), expressing active power distribution network node power balance constraint by using formulas (12) to (14), expressing line current constraint conversion by using a formula (15), and expressing distribution transformer operation constraint by using a formula (16), and obtaining a convex processed model;
s45, solving the model in the step S44 to obtain a load growth factor lambda, and calculating the load capacity TSC of the active power distribution network according to the load growth factor lambda, wherein the calculation method comprises the following steps:
Figure BDA0001563477370000061
preferably, when the actual load of the active power distribution network is greater than the maximum load capacity of the active power distribution network under the expected accident condition set in the step S40, the active power distribution network is in an unsafe operation state, and an early warning signal is sent out; and when the actual load of the active power distribution network is smaller than the maximum load capacity of the active power distribution network under the expected accident condition set in the step S40, the active power distribution network is in a safe operation state and does not need to send out an early warning signal.
Compared with the prior art, the invention has the beneficial effects that:
the method for evaluating the load capacity safety of the active power distribution network under the expected accident condition can consider various expected accident situations of the active power distribution network, and take account of the influence of the continuous reactive power compensation device, the discrete reactive power compensation device and the distributed power supply on the load capacity safety evaluation of the active power distribution network, so that the safety of the load capacity of the active power distribution network under the expected accident condition can be accurately evaluated, the defects of the traditional method for calculating the maximum power supply capacity of the power distribution network are overcome, and the problem of the safety evaluation of the load capacity of the active power distribution network under the expected accident condition can be accurately solved; on one hand, the method is beneficial to analyzing the adaptability of the existing power distribution network to load development and the load safety margin by a power distribution network management department, and is beneficial to finding the weak links of the existing network frame, thereby providing important reference information for planning of the active power distribution network; on the other hand, the power distribution network operation mode guidance can be provided for power distribution network operation management personnel, the power distribution network operation mode guidance is helpful for guaranteeing the safety and reliability of power supply of the power distribution network, and the operation level of the power distribution network is improved.
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Fig. 1 is a flowchart of an active power distribution network load capacity safety assessment method under an expected accident condition.
Detailed Description
The present invention will be further described with reference to the following embodiments. Wherein the showings are for the purpose of illustration only and are shown by way of illustration only and not in actual form, and are not to be construed as limiting the present patent; to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.
The same or similar reference numerals in the drawings of the embodiments of the present invention correspond to the same or similar components; in the description of the present invention, it should be understood that if there is an orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", etc. based on the orientation or positional relationship shown in the drawings, it is only for convenience of describing the present invention and simplifying the description, but it is not intended to indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and are not to be construed as limiting the present patent, and the specific meaning of the terms may be understood by those skilled in the art according to specific circumstances.
Example 1
Fig. 1 shows an embodiment of the safety evaluation method for load capacity of an active distribution network under an expected accident condition according to the present invention, which includes the following steps:
s10, acquiring basic data of safety evaluation of the load capacity of the active power distribution network; the basic data comprise basic physical data and basic operation data, wherein the basic physical data comprise line resistance and reactance parameters, maximum current values allowed by a line, lower and upper reactive power limits of a continuous reactive power compensation device, single-group reactive power compensation capacity and maximum switching group number of a discrete reactive power compensation device, and maximum apparent power of a distributed power supply; the basic operation data comprise a lower bound and an upper bound of a node voltage amplitude value, basic state active power and reactive power of a load and an active power predicted value of a distributed power supply;
s20, based on the basic number in the step S10According to the method, an expected accident set of the safety assessment of the load capacity of the active power distribution network is determined, wherein the expected accident is selected from one or more combinations of single main transformer faults, multiple main transformer faults, single main transformer overhaul, multiple main transformer overhaul, single line faults, multiple line faults, single line overhaul and multiple line overhaul; setting expected accidents
Figure BDA0001563477370000071
Determine the set of expected accidents
Figure BDA0001563477370000072
S30, establishing an active distribution network load capacity safety assessment model under the condition of the expected accident based on the basic data acquired in the step S10 and the expected accident set determined in the step S20, and specifically comprising the following steps:
s31, establishing a target function of the active power distribution network load capacity safety evaluation model under the expected accident condition by taking the maximum load capacity of the active power distribution network as a target, wherein the target function is shown as the following formula:
max λ (1)
in the formula (1), lambda is a load increase factor;
s32, determining active power distribution network node power balance constraint:
Figure BDA0001563477370000073
in formula (2):
Figure BDA0001563477370000074
and
Figure BDA0001563477370000075
respectively expected accident phisThe voltage amplitudes of nodes i and j under the condition; gijAnd BijConductance and susceptance, respectively, of the line (i, j);
Figure BDA0001563477370000076
to anticipate an accident phisSection under the conditionVoltage phase angle difference of points i and j;
Figure BDA0001563477370000077
Pi Land Pi DG,φsRespectively expected accident phisThe active power of a generator, a load and a distributed power supply injection node i is generated under the condition;
Figure BDA0001563477370000081
and
Figure BDA0001563477370000082
respectively expected accident phisInjecting reactive power of a node i into the generator, the load, the distributed power supply, the continuous reactive power compensation device and the discrete reactive power compensation device under the condition; Θ (i) is a set of nodes connected to node i;
setting new variables
Figure BDA0001563477370000083
And
Figure BDA0001563477370000084
as follows:
Figure BDA0001563477370000085
the active distribution network node power balance constraint can be expressed as:
Figure BDA0001563477370000086
s33, determining node voltage amplitude constraint:
Figure BDA0001563477370000087
in formula (5): vi,minAnd Vi,maxRespectively a lower bound and an upper bound of the voltage amplitude of the node i;
s34, determining the current constraint of the line:
Figure BDA0001563477370000088
in formula (6):
Figure BDA0001563477370000089
and Iij,maxRespectively expected accident phisThe amplitude of the current through the line (i, j) under the conditions and its upper bound;
s35, determining operation constraint of the distribution transformer:
Figure BDA00015634773700000810
in the formula (7), the reaction mixture is,
Figure BDA00015634773700000811
is the maximum apparent power of the distribution transformer connected between the root node o and the node i of the substation;
s36, determining the operation constraint of the continuous reactive power compensation device:
Figure BDA0001563477370000091
in formula (8):
Figure BDA0001563477370000092
and
Figure BDA0001563477370000093
respectively expected accident phisReactive power of a continuous reactive power compensation device connected to the node i under the condition, and a lower bound and an upper bound of the reactive power;
s37, determining the operation constraint of the discrete reactive power compensation device:
Figure BDA0001563477370000094
in formula (9):
Figure BDA0001563477370000095
and
Figure BDA0001563477370000096
respectively expected accident phisReactive power and switching group number of the discrete reactive power compensation device connected to the node i under the condition;
Figure BDA0001563477370000097
and Wi DCRespectively switching the reactive power and the maximum switching group number when the discrete reactive power compensation device connected to the node i switches the single group capacity;
s38, determining the operation constraint of the distributed power supply:
Figure BDA0001563477370000098
in formula (10): pi DG,PreAnd
Figure BDA0001563477370000099
respectively a maximum active power predicted value and a maximum apparent power of a distributed power supply connected to a node i;
Figure BDA00015634773700000910
to anticipate an accident phisA power factor angle of a distributed power supply conditionally connected at node i;
s39, determining radial grid structure constraint of the active power distribution network:
Figure BDA00015634773700000911
in formula (11): n is a node set except a root node of the transformer substation; NS is a set of substation root nodes; e is the set of the common line and the distribution transformer line; the first term of the above equation is used to determine whether the line is in the radial grid structure of the distribution network, for
Figure BDA00015634773700000912
Introducing two binary variables
Figure BDA00015634773700000913
And
Figure BDA00015634773700000914
if node j is the parent node of node i
Figure BDA00015634773700000915
Or node i is a parent node of node j
Figure BDA00015634773700000916
Then
Figure BDA00015634773700000917
At the moment, the lines (i, j) normally run in the radial distribution network frame; if it is not
Figure BDA00015634773700000918
And
Figure BDA00015634773700000919
then
Figure BDA00015634773700000920
At this point, line (i, j) exits service; the second constraint in the formula (11) is used for limiting each node to have only one parent node, and the third constraint in the formula (11) is used for limiting the root node of the transformer substation not to have a parent node;
s40, performing convex processing on the model in the step S30, solving the model obtained after the convex processing, obtaining the load capacity of the active power distribution network, obtaining the maximum load capacity of the active power distribution network under different expected accident conditions, and evaluating the safety of the load capacity of the active power distribution network; the specific implementation steps are as follows:
s41, converting the node power balance constraint of the active power distribution network into:
Figure BDA0001563477370000101
Figure BDA0001563477370000102
Figure BDA0001563477370000103
s42, converting the line current constraint into:
Figure BDA0001563477370000104
s43, converting the operation constraint of the distribution transformer into:
Figure BDA0001563477370000105
s44, expressing an objective function by using a formula (1), expressing node voltage amplitude constraint by using a formula (5), expressing continuous reactive power compensation device operation constraint by using a formula (8), expressing discrete reactive power compensation device operation constraint by using a formula (9), expressing distributed power supply operation constraint by using a formula (10), expressing active power distribution network radial grid constraint by using a formula (11), expressing active power distribution network node power balance constraint by using formulas (12) to (14), expressing line current constraint conversion by using a formula (15), and expressing distribution transformer operation constraint by using a formula (16), and obtaining a convex processed model;
s45, solving the model in the step S44 to obtain a load growth factor lambda, and calculating the load capacity TSC of the active power distribution network according to the load growth factor lambda, wherein the calculation method comprises the following steps:
Figure BDA0001563477370000111
when the actual load of the active power distribution network is greater than the maximum load capacity of the active power distribution network under the expected accident condition set in the step S40, the active power distribution network is in an unsafe operation state, and an early warning signal is sent out; and when the actual load of the active power distribution network is smaller than the maximum load capacity of the active power distribution network under the expected accident condition set in the step S40, the active power distribution network is in a safe operation state and does not need to send out an early warning signal.
It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims (4)

1. A safety assessment method for load capacity of an active power distribution network under an expected accident condition is characterized by comprising the following steps:
s10, acquiring basic data of safety evaluation of the load capacity of the active power distribution network; the basic data comprise basic physical data and basic operation data, wherein the basic physical data comprise line resistance and reactance parameters, maximum current values allowed by a line, lower and upper reactive power limits of a continuous reactive power compensation device, single-group reactive power compensation capacity and maximum switching group number of a discrete reactive power compensation device, and maximum apparent power of a distributed power supply; the basic operation data comprise a lower bound and an upper bound of a node voltage amplitude value, basic state active power and reactive power of a load and an active power predicted value of a distributed power supply;
s20, determining an expected accident set of load capacity safety assessment of the active power distribution network based on the basic data in the step S10, wherein the expected accident set is selected from one or more combinations of single main transformer faults, multiple main transformer faults, single main transformer overhaul, multiple main transformer overhaul, single line faults, multiple line faults, single line overhaul and multiple line overhaul;
s30, establishing an active power distribution network load capacity safety assessment model under the condition of expected accidents based on the basic data acquired in the step S10 and the expected accident set determined in the step S20;
s40, performing convex processing on the model in the step S30, solving the model obtained after the convex processing, obtaining the load capacity of the active power distribution network, obtaining the maximum load capacity of the active power distribution network under different expected accident conditions, and evaluating the safety of the load capacity of the active power distribution network;
the safety evaluation model for the load capacity of the active power distribution network under the expected accident condition in the step S30 is carried out according to the following steps:
s31, establishing a target function of the active power distribution network load capacity safety evaluation model under the expected accident condition by taking the maximum load capacity of the active power distribution network as a target, wherein the target function is shown as the following formula:
max λ (1)
in the formula (1), lambda is a load increase factor;
s32, determining active power distribution network node power balance constraint:
Figure FDA0002604626660000011
in formula (2):
Figure FDA0002604626660000021
and
Figure FDA0002604626660000022
respectively expected accident phisThe voltage amplitudes of nodes i and j under the condition; gijAnd BijConductance and susceptance, respectively, of the line (i, j);
Figure FDA0002604626660000023
to anticipate an accident phisVoltage phase angle difference of nodes i and j under the condition;
Figure FDA0002604626660000024
Pi Land, and
Figure FDA0002604626660000025
respectively expected accident phisThe active power of a generator, a load and a distributed power supply injection node i is generated under the condition;
Figure FDA0002604626660000026
Qi L、
Figure FDA0002604626660000027
and
Figure FDA0002604626660000028
respectively expected accident phisInjecting reactive power of a node i into the generator, the load, the distributed power supply, the continuous reactive power compensation device and the discrete reactive power compensation device under the condition; Θ (i) is a set of nodes connected to node i;
setting new variables
Figure FDA0002604626660000029
And
Figure FDA00026046266600000210
as follows:
Figure FDA00026046266600000211
the active distribution network node power balance constraint can be expressed as:
Figure FDA00026046266600000212
s33, determining node voltage amplitude constraint:
Figure FDA00026046266600000213
in formula (5): vi,minAnd Vi,maxRespectively being nodes iA lower and an upper voltage amplitude bound;
s34, determining the current constraint of the line:
Figure FDA00026046266600000214
in formula (6):
Figure FDA00026046266600000215
and Iij,maxRespectively expected accident phisThe amplitude of the current through the line (i, j) under the conditions and its upper bound;
s35, determining operation constraint of the distribution transformer:
Figure FDA00026046266600000216
in the formula (7), the reaction mixture is,
Figure FDA0002604626660000031
is the maximum apparent power of the distribution transformer connected between the root node o and the node i of the substation;
s36, determining the operation constraint of the continuous reactive power compensation device:
Figure FDA0002604626660000032
in formula (8):
Figure FDA0002604626660000033
and
Figure FDA0002604626660000034
respectively expected accident phisReactive power of a continuous reactive power compensation device connected to the node i under the condition, and a lower bound and an upper bound of the reactive power;
s37, determining the operation constraint of the discrete reactive power compensation device:
Figure FDA0002604626660000035
in formula (9):
Figure FDA0002604626660000036
and
Figure FDA0002604626660000037
respectively expected accident phisReactive power and switching group number of the discrete reactive power compensation device connected to the node i under the condition;
Figure FDA0002604626660000038
and Wi DCRespectively switching the reactive power and the maximum switching group number when the discrete reactive power compensation device connected to the node i switches the single group capacity;
s38, determining the operation constraint of the distributed power supply:
Figure FDA0002604626660000039
in formula (10): pi DG,PreAnd
Figure FDA00026046266600000310
respectively a maximum active power predicted value and a maximum apparent power of a distributed power supply connected to a node i;
Figure FDA00026046266600000311
to anticipate an accident phisA power factor angle of a distributed power supply conditionally connected at node i;
s39, determining radial grid structure constraint of the active power distribution network:
Figure FDA00026046266600000312
in formula (11): n is a node set except a root node of the transformer substation; NS is a set of substation root nodes; e is the set of the common line and the distribution transformer line; the first term of the above equation is used to determine whether the line is in the radial grid structure of the distribution network, for
Figure FDA00026046266600000313
Introducing two binary variables
Figure FDA00026046266600000314
And
Figure FDA00026046266600000315
if node j is the parent node of node i
Figure FDA0002604626660000041
Or node i is a parent node of node j
Figure FDA0002604626660000042
Then
Figure FDA0002604626660000043
At the moment, the lines (i, j) normally run in the radial distribution network frame; if it is not
Figure FDA0002604626660000044
And
Figure FDA0002604626660000045
then
Figure FDA0002604626660000046
At this point, line (i, j) exits service;
step S40 is performed according to the following steps:
s41, converting the node power balance constraint of the active power distribution network into:
Figure FDA0002604626660000047
Figure FDA0002604626660000048
Figure FDA0002604626660000049
s42, converting the line current constraint into:
Figure FDA00026046266600000410
s43, converting the operation constraint of the distribution transformer into:
Figure FDA00026046266600000411
s44, expressing an objective function by using a formula (1), expressing node voltage amplitude constraint by using a formula (5), expressing continuous reactive power compensation device operation constraint by using a formula (8), expressing discrete reactive power compensation device operation constraint by using a formula (9), expressing distributed power supply operation constraint by using a formula (10), expressing active power distribution network radial grid constraint by using a formula (11), expressing active power distribution network node power balance constraint by using formulas (12) to (14), expressing line current constraint conversion by using a formula (15), and expressing distribution transformer operation constraint by using a formula (16), and obtaining a convex processed model;
s45, solving the model in the step S44 to obtain a load increase factor lambda, and calculating the load capacity TSC of the active power distribution network according to the load increase factor, wherein the calculation method comprises the following steps:
Figure FDA0002604626660000051
2. the method for safely evaluating the load capacity of the active distribution network under the expected accident condition according to claim 1, wherein the expected accident is set in step S20
Figure FDA0002604626660000052
S is 1,2, …, S, and the set of expected accidents is determined to be
Figure FDA0002604626660000053
3. The safety assessment method for load capacity of the active power distribution network under the expected accident condition according to claim 1, wherein the second term in the formula (11) is used for limiting each node to have only one parent node, and the third term in the formula (11) is used for limiting the root node of the substation not to have the parent node.
4. The active power distribution network load capacity safety assessment method under the expected accident condition according to claim 1, wherein when the actual load of the active power distribution network is greater than the maximum load capacity of the active power distribution network under the expected accident condition set in the step S40, the active power distribution network is in an unsafe operation state and sends out an early warning signal; and when the actual load of the active power distribution network is smaller than the maximum load capacity of the active power distribution network under the expected accident condition set in the step S40, the active power distribution network is in a safe operation state and does not need to send out an early warning signal.
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Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1143593A1 (en) * 1995-12-20 2001-10-10 General Dynamics Ordnance and Tactical Systems, Inc. Load distribution and management system
CN101431238A (en) * 2008-09-12 2009-05-13 天津天大求实电力新技术股份有限公司 Power distribution network power supply capacity evaluation method considering N-1 criterion
CN102025153A (en) * 2010-12-15 2011-04-20 天津大学 Method for accurately calculating maximum power supply capacity of medium voltage distribution network
CN104716641A (en) * 2015-01-06 2015-06-17 上海电力学院 Method for assessing power supply capacity of power distribution network provided with distributed generation
CN106169750A (en) * 2016-07-29 2016-11-30 清华大学 A kind of active distribution network net capability computational methods lax based on second order cone
CN107394785A (en) * 2017-07-03 2017-11-24 中国南方电网有限责任公司电网技术研究中心 The method and device of power distribution network vulnerability assessment

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1143593A1 (en) * 1995-12-20 2001-10-10 General Dynamics Ordnance and Tactical Systems, Inc. Load distribution and management system
CN101431238A (en) * 2008-09-12 2009-05-13 天津天大求实电力新技术股份有限公司 Power distribution network power supply capacity evaluation method considering N-1 criterion
CN102025153A (en) * 2010-12-15 2011-04-20 天津大学 Method for accurately calculating maximum power supply capacity of medium voltage distribution network
CN104716641A (en) * 2015-01-06 2015-06-17 上海电力学院 Method for assessing power supply capacity of power distribution network provided with distributed generation
CN106169750A (en) * 2016-07-29 2016-11-30 清华大学 A kind of active distribution network net capability computational methods lax based on second order cone
CN107394785A (en) * 2017-07-03 2017-11-24 中国南方电网有限责任公司电网技术研究中心 The method and device of power distribution network vulnerability assessment

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