CN108923540B - Power distribution network feeder load acquisition method and device based on segmented measurement - Google Patents

Power distribution network feeder load acquisition method and device based on segmented measurement Download PDF

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CN108923540B
CN108923540B CN201810989822.5A CN201810989822A CN108923540B CN 108923540 B CN108923540 B CN 108923540B CN 201810989822 A CN201810989822 A CN 201810989822A CN 108923540 B CN108923540 B CN 108923540B
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value
distribution area
power distribution
target power
load
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CN108923540A (en
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李文云
曹敏
刘柱揆
刘红文
王洪林
苏兴磊
吴楚
杨志斌
赵现平
王科
黄星
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Electric Power Research Institute of Yunnan Power Grid Co Ltd
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Electric Power Research Institute of Yunnan Power Grid Co Ltd
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    • H02J13/0079—
    • 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
    • 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

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Abstract

The embodiment of the application discloses a method and a device for acquiring feeder load of a power distribution network based on sectional measurement, firstly, according to acquired measured feeder load data at two ends of a target power distribution area, calculating total load of the target power distribution area and an actual terminal power value of the target power distribution area, then according to the total load of the target power distribution area and an acquired estimated value of branch point load capacity, calculating each branch point load value of the target power distribution area, acquiring a first load calculation value of M sections of feeders in the target power distribution area, then acquiring a calculated terminal complex power value of the target power distribution area, then comparing the calculated terminal complex power value of the target power distribution area with the actual terminal complex power value of the target power distribution area, calculating an absolute value of a difference value of the two values, and continuously iterating through a preset threshold value to reduce the absolute value until the requirement that the absolute value is smaller than the preset threshold value is met.

Description

Method and device for acquiring feeder load of power distribution network based on segmented measurement
Technical Field
The application relates to the field of distribution automation systems, in particular to a method and a device for acquiring feeder load of a power distribution network based on sectional measurement.
Background
In the electric power system, the distribution automation system guarantees the reliability of power supply and distribution of a distribution network. As shown in fig. 1, a power distribution automation system is generally divided into 3 levels: the power distribution dispatching center, the power distribution substation and the measuring equipment layer are connected through a communication network at different levels. The power distribution dispatching center is the core for determining the operation mode of the whole power distribution network, the power distribution substation is an intermediate link for connecting a measuring equipment layer and the power distribution dispatching center, the measuring equipment layer consists of a plurality of measuring equipment arranged at the load position along a feeder line and is used for measuring the load of the feeder line in real time and providing data support for realizing power distribution automation, and the load of the feeder line comprises a voltage effective value, a current effective value, active power, reactive power and the like.
The distribution network is divided into a plurality of distribution areas, one distribution area includes a plurality of feeder lines, and measuring equipment is generally installed at the load position along the feeder lines and used for measuring the load of the feeder lines in real time. The medium-voltage distribution network in the distribution network is high in structural complexity, the number of feeder sections and the number of loads are large, and measuring equipment cannot be installed at all loads in the medium-voltage distribution network generally but is installed selectively in consideration of cost. Under the condition, the feeder load of the measuring equipment which is not installed cannot be obtained, so that data support cannot be provided for realizing distribution automation. For this situation, a common solution at present is to replace the feeder load of the neighboring measuring device not installed with the feeder load obtained by the installed measuring device in a distribution area of the medium voltage distribution network, or to obtain the average feeder load value by calculating the difference of the feeder loads obtained by the measuring devices at both ends when the measuring device is not installed in the middle several feeder sections in a distribution area of the medium voltage distribution network, and then dividing the difference by the number of feeder sections in the distribution area, and using the obtained average feeder load value as the feeder load of each feeder section in the distribution area.
However, in the research process of the present application, the inventor finds that the medium voltage distribution network has a complex structure, the loads accessed by each feeder have different differences, the loads accessed by different feeders at different time points also have different changes, and if a known feeder load or a feeder load average value is used for replacing an unknown feeder load, the obtained feeder load has a large error with the actual feeder load. The feeder load plays an important role in realizing distribution automation, and when a distribution automation system needs to perform advanced functions such as security assessment, network reconstruction and load prediction, reliable feeder load is required to be used as data support, so that a method for acquiring the feeder load of a distribution network is urgently needed to improve the accuracy of acquiring the feeder load in the prior art.
Disclosure of Invention
In order to improve the accuracy of acquiring the load of the feeder line of the power distribution network in the prior art, the invention discloses a method and a device for acquiring the load of the feeder line of the power distribution network based on sectional measurement through the following embodiments.
In a first aspect of the present invention, a method for acquiring feeder load of a distribution network based on segmented measurement is disclosed, which includes:
11 Obtaining head end measurement data and tail end measurement data of a target power distribution area, wherein the target power distribution area is any one of power distribution areas needing to obtain feeder loads in a power distribution network, the target power distribution area comprises M sections of feeders, the head end measurement data of the target power distribution area comprises a head end voltage measurement value, a head end active power measurement value and a head end reactive power measurement value, and the tail end measurement data of the target power distribution area comprises a tail end active power measurement value and a tail end reactive power measurement value;
12 Calculating a total load of the target power distribution area and a terminal complex power actual value of the target power distribution area according to the head end measurement data and the terminal measurement data of the target power distribution area, wherein the total load of the target power distribution area comprises a total active power value and a total reactive power value of the target power distribution area;
13 Obtaining an estimated value of a load capacity of a branch point of the target power distribution area, and obtaining a load value of each branch point of the target power distribution area according to a total load of the target power distribution area and the estimated value of the load capacity of the branch point, where the branch point is a node of a load connected to an end of each feeder line in the M feeder lines, the load value of the branch point is a load connected to an end of each feeder line, the load value of each branch point includes a calculated value of active power and a calculated value of reactive power, and the calculated value of complex power of each branch point is obtained according to the calculated value of active power and the calculated value of reactive power of each branch point;
14 Obtaining first calculated load values for M feeder sections in the target power distribution area based on the head end measured data for the target power distribution area and each branch point load value for the target power distribution area, wherein the first calculated load values include a head end calculated load value and a tail end calculated load value, the head end calculated load values include a head end calculated current value, a head end calculated voltage value and a head end calculated complex power value, and the tail end calculated load values include a tail end calculated current value, a tail end calculated voltage value and a tail end calculated complex power value;
15 Obtaining an absolute value deltaS of a difference value between a terminal complex power calculated value of the target power distribution area and a terminal complex power actual value of the target power distribution area, wherein the terminal complex power calculated value of the target power distribution area is a terminal complex power calculated value of the last feeder line in the M feeder lines;
16 ) determining whether the absolute value Δ S is smaller than a preset first threshold value epsilon;
17 If the absolute value Δ S is greater than or equal to the first threshold value epsilon, obtaining a difference value between the total load of the target power distribution area and the absolute value Δ S, updating the total load of the target power distribution area to the difference value, and returning to execute the operation of the step 13) according to the updated total load of the target power distribution area;
18 If the absolute value deltas is smaller than the first threshold epsilon, determining the feeder load of the distribution network as a load calculation value of the M feeder sections;
19 Obtaining the feeder load of the distribution network according to the first load calculation value of the M feeder sections.
Optionally, calculating a total load of the target power distribution area and an actual value of the terminal complex power of the target power distribution area according to the head end measurement data and the terminal measurement data of the target power distribution area, including:
calculating the total load of the target power distribution area according to the head end active power measured value, the head end reactive power measured value, the tail end active power measured value and the tail end reactive power measured value of the target power distribution area by the following formula:
P A ＝P 1 -P 2 ；
Q A ＝Q 1 -Q 2 ；
wherein, P A Is the total active power value, Q, of the target power distribution area A Is the total reactive power value, P, of the target distribution area 1 Is the first end active power measurement, Q, of the target distribution area 1 Is a head end reactive power measurement value, P, of the target distribution area 2 Is a terminal active power measurement, Q, of the target distribution area 2 Is an end reactive power measurement value for the target power distribution zone;
according to the terminal active power measurement value and the terminal reactive power measurement value of the target power distribution area, acquiring a terminal complex power actual value of the target power distribution area through the following formula:
S 2 ＝P 2 +jQ 2 ；
wherein S is 2 Is the terminal complex power actual value of the target power distribution area, and j is an imaginary unit.
Optionally, obtaining a first load calculation value of M feeder lines in the target power distribution area according to the head end measurement data of the target power distribution area and the load value of each branch point of the target power distribution area, including:
acquiring a terminal load calculation value of a first section of feeder line and a head end load calculation value of a second section of feeder line in the target power distribution area according to the head end measurement data of the target power distribution area and the branch point load value of the first section of feeder line in the target power distribution area;
and acquiring a terminal load calculated value of the a-th section feeder line and a head load calculated value of the (a + 1) th section feeder line in the target distribution area until acquiring a terminal load calculated value of the M-th section feeder line according to the head load calculated value of the a-th section feeder line in the target distribution area and the branch point load value of the a-th section feeder line in the target distribution area, wherein a is a positive integer less than M.
Optionally, obtaining a terminal load calculation value of the first section of feeder line and a head load calculation value of the second section of feeder line in the target power distribution area according to the head measurement data of the target power distribution area and the branch point load value of the first section of feeder line in the target power distribution area, includes:
according to the head end measurement data of the target power distribution area, acquiring a head end complex power actual value of the target power distribution area through the following formula:
S 1 ＝P 1 +jQ 1 ；
wherein S is 1 Is the actual value of the head end complex power of the target distribution area, j is an imaginary unit, P 1 Is a measurement value, Q, of the active power at the head end of the target distribution area 1 The first-end reactive power measurement value of the target power distribution area is obtained;
obtaining a current calculation value of a first section of feeder line in the target power distribution area according to the head end voltage measurement value of the target power distribution area and the head end complex power actual value of the target power distribution area by the following formula:
Figure GDA0003331480490000041
wherein the content of the first and second substances,
Figure GDA0003331480490000042
is a calculated value of the current of the first section of the feeder line in the target distribution area,
Figure GDA0003331480490000043
is a head end voltage measurement of the target power distribution area;
acquiring an impedance value of each feeder line section in the target power distribution area, and acquiring a voltage calculation value of a branch point of a first feeder line section in the target power distribution area according to the impedance value of the first feeder line section in the target power distribution area, a current calculation value of the first feeder line section in the target power distribution area and a head end voltage measurement value of the target power distribution area by the following formula:
Figure GDA0003331480490000044
wherein the content of the first and second substances,
Figure GDA0003331480490000045
is a calculated voltage value, Z, of a branch point of a first section of the feeder line in the target distribution area LN1 Is an impedance value of a first section of feeder line in the target power distribution area;
according to the voltage calculation value of the branch point of the first section of the feeder line in the target power distribution area and the current calculation value of the first section of the feeder line in the target power distribution area, acquiring a terminal complex power calculation value of the first section of the feeder line in the target power distribution area through the following formula:
Figure GDA0003331480490000046
wherein S is LN1 Is a calculated value of the terminal complex power of the first section of feeder line in the target power distribution area;
acquiring a complex power calculated value of a branch point load of a first section of feeder line in the target power distribution area, and acquiring a current calculated value of the branch point load of the first section of feeder line in the target power distribution area according to the complex power calculated value of the branch point load of the first section of feeder line in the target power distribution area and a voltage calculated value of the branch point of the first section of feeder line in the target power distribution area by the following formula:
Figure GDA0003331480490000047
wherein the content of the first and second substances,
Figure GDA0003331480490000048
is the calculated value of the current of the branch point load of the first section of the feeder line in the target distribution area, S L1 Is a complex power calculation value of a branch point load of a first section of feeder line in the target power distribution area;
according to the current calculated value of the first section of feeder line in the target power distribution area and the current calculated value of the branch point load of the first section of feeder line in the target power distribution area, obtaining the current calculated value of the second section of feeder line in the target power distribution area through the following formula:
Figure GDA0003331480490000051
wherein the content of the first and second substances,
Figure GDA0003331480490000052
is the calculated current value of the second section of feeder line in the target power distribution area;
according to the calculated current value of the second section of feeder line in the target power distribution area and the calculated voltage value of the branch point of the first section of feeder line in the target power distribution area, the calculated first-end complex power value of the second section of feeder line in the target power distribution area is obtained through the following formula:
Figure GDA0003331480490000053
wherein S is LN2 Is a first-end complex power calculated value of a second section of the feeder line in the target power distribution area.
Optionally, when the measurement data at the two ends of the target power distribution area does not have power measurement data, the method for acquiring the feeder load of the power distribution network further includes:
51 Obtaining head end measurement data and tail end measurement data of the target power distribution area, wherein the measurement data are current measurement values and voltage measurement values;
52 Calculating a total current of the target power distribution area according to the head end current measurement value and the tail end current measurement value of the target power distribution area;
53 Obtaining an estimated value of the load capacity of branch points in the target power distribution area, and distributing the current value of each branch point load in the target power distribution area according to the total current of the target power distribution area and the estimated value of the load capacity of the branch points;
54 Obtaining second load calculation values of M feeder lines in the target power distribution area according to the head end measurement data of the target power distribution area and the current value of each branch point load of the target power distribution area, wherein the second load calculation values include a current calculation value and a voltage calculation value;
55 Obtaining an absolute value Δ I of a difference between a calculated terminal current value of the target power distribution area and a measured terminal current value of the target power distribution area, wherein the calculated terminal current value of the target power distribution area is a calculated current value of a last feeder in the M feeder sections;
56 ) determining whether the absolute value Δ I is smaller than a preset first threshold value epsilon;
57 If the absolute value Δ I is greater than or equal to the first threshold value epsilon, obtaining a difference value between the total current of the target power distribution area and the absolute value Δ I, updating the total current of the target power distribution area to the difference value, and returning to execute the operation of the step 53) according to the updated total current of the target power distribution area;
58 If the absolute value delta I is smaller than the first threshold value epsilon, determining the feeder load of the power distribution network as a load calculation value of the M feeder sections;
59 Obtaining the feeder load of the distribution network according to the second load calculation value of the M feeder lines.
Optionally, calculating the total current of the target power distribution area according to the head end current measurement value and the tail end current measurement value of the target power distribution area, including:
obtaining the total current of the target power distribution area according to the head end current measurement value and the tail end current measurement value of the target power distribution area through the following formula:
I A ＝I 1 -I 2 ；
wherein, I A Is the target distribution area total current, I 1 Is a head end current measurement value, I, of the target distribution area 2 Is an end current measurement of the target power distribution zone.
Optionally, obtaining a second load calculation value of M feeder lines in the target power distribution area according to the head end measurement data of the target power distribution area and the current value of each branch point load in the target power distribution area, including:
acquiring a second load calculation value of a second section of feeder line in the target power distribution area according to the head end measurement data of the target power distribution area and the current value of the branch point load of the first section of feeder line in the target power distribution area;
and acquiring a second load calculation value of the (a + 1) th feeder line in the target power distribution area according to the second load calculation value of the a-th feeder line in the target power distribution area and the current value of the branch point load of the a-th feeder line in the target power distribution area until acquiring a second load calculation value of the M-th feeder line, wherein a is a positive integer smaller than M.
Optionally, obtaining a second load calculation value of a second section of feeder line in the target power distribution area according to the head end measurement data of the target power distribution area and the current value of the branch point load of the first section of feeder line in the target power distribution area, includes:
acquiring the resistance value of each section of feeder line in the target power distribution area, and acquiring a voltage calculation value of a branch point of a first section of feeder line in the target power distribution area according to the resistance value of a first section of feeder line in the target power distribution area, the head end current measurement value and the head end voltage measurement value of the target power distribution area by the following formula:
Figure GDA0003331480490000061
wherein the content of the first and second substances,
Figure GDA0003331480490000062
is a calculated value of the voltage at the branch point of the first stage feeder line in the target distribution area,
Figure GDA0003331480490000063
is a head end voltage measurement, R, of the target distribution area LN1 Is the resistance of the first section of the feed line in the target distribution area,
Figure GDA0003331480490000064
is a head end current measurement of the target power distribution area;
according to the head end current measurement value of the target power distribution area and the current value of the branch point load of the first section of feeder line in the target power distribution area, obtaining the current calculation value of the second section of feeder line in the target power distribution area through the following formula:
Figure GDA0003331480490000065
wherein the content of the first and second substances,
Figure GDA0003331480490000066
is a calculated value of the current of the second section of the feeder line in the target power distribution area,
Figure GDA0003331480490000067
is the current value of the branch point load of the first section of the feeder line in the target distribution area.
In a second aspect of the present invention, a distribution network feeder load obtaining apparatus based on segmented measurement is disclosed, which includes:
the first measurement data acquisition module is used for acquiring head end measurement data and tail end measurement data of a target power distribution area, wherein the target power distribution area is any one of power distribution areas needing to acquire feeder loads in a power distribution network, the target power distribution area comprises M sections of feeders, the head end measurement data of the target power distribution area comprises a head end voltage measurement value, a head end active power measurement value and a head end reactive power measurement value, and the tail end measurement data of the target power distribution area comprises a tail end active power measurement value and a tail end reactive power measurement value;
a total load calculation module, configured to obtain a total load of the target power distribution area and a terminal complex power actual value of the target power distribution area according to head end measurement data and terminal measurement data of the target power distribution area, where the total load of the target power distribution area includes a total active power value and a total reactive power value of the target power distribution area;
a first distribution module, configured to obtain an estimated value of a branch point load capacity of the target power distribution area, and obtain each branch point load value of the target power distribution area according to a total load of the target power distribution area and the estimated value of the branch point load capacity, where the branch point is a node at which a load is connected to an end of each feeder in the M feeder sections, the branch point load is a load connected to an end of each feeder, each branch point load value includes an active power calculated value and a reactive power calculated value, and a complex power calculated value of each branch point load is obtained according to the active power calculated value and the reactive power calculated value of each branch point load;
a first calculated load value obtaining module, configured to obtain first calculated load values of M feeder segments in the target power distribution area according to the head end measurement data of the target power distribution area and each branch point load value of the target power distribution area, where the first calculated load value includes a head end load calculated value and a tail end load calculated value, the head end load calculated value includes a head end current calculated value, a head end voltage calculated value and a head end complex power calculated value, and the tail end load calculated value includes a tail end current calculated value, a tail end voltage calculated value and a tail end complex power calculated value;
a first absolute value obtaining module, configured to obtain an absolute value Δ S of a difference between a terminal complex power calculated value of the target power distribution area and a terminal complex power actual value of the target power distribution area, where the terminal complex power calculated value of the target power distribution area is a terminal complex power calculated value of a last feeder line in the M feeder lines;
the first judgment module is used for judging whether the absolute value delta S is smaller than a preset first threshold value epsilon or not;
a first execution module, configured to, if the absolute value Δ S is greater than or equal to the first threshold value epsilon, obtain a difference between a total load of the target power distribution area and the absolute value Δ S, update the total load of the target power distribution area to the difference, and return to execute an operation of the first distribution module according to the updated total load of the target power distribution area;
a second execution module, configured to determine that the feeder load of the power distribution network is a load calculation value of the M feeder sections if the absolute value Δ S is smaller than the first threshold epsilon;
and the first feeder line load obtaining module is used for obtaining the feeder line load of the power distribution network according to the first load calculation value of the M feeder lines.
Optionally, when the measurement data at two ends of the target power distribution area does not have power measurement data, the feeder load acquiring device for the power distribution network further includes:
the second measurement data acquisition module is used for acquiring head end measurement data and tail end measurement data of the target power distribution area, wherein the measurement data are a current measurement value and a voltage measurement value;
the total current calculation module is used for calculating the total current of the target power distribution area according to the head end current measurement value and the tail end current measurement value of the target power distribution area;
the second distribution module is used for acquiring the estimated value of the branch point load capacity of the target power distribution area and distributing the current value of each branch point load of the target power distribution area according to the total current of the target power distribution area and the estimated value of the branch point load capacity;
a second load calculation value obtaining module, configured to obtain second load calculation values of M feeder lines in the target power distribution area according to the data measured at the head end of the target power distribution area and the current value of each branch point load of the target power distribution area, where the second load calculation values include a current calculation value and a voltage calculation value;
a second absolute value obtaining module, configured to obtain an absolute value Δ I of a difference between a calculated value of a terminal current of the target power distribution area and a measured value of the terminal current of the target power distribution area, where the calculated value of the terminal current of the target power distribution area is a calculated value of a current of a last feeder line of the M feeder lines;
the second judgment module is used for judging whether the absolute value delta I is smaller than a preset first threshold value epsilon or not;
a third executing module, configured to, if the absolute value Δ I is greater than or equal to the first threshold value ∈, obtain a difference between the target power distribution area total current and the absolute value Δ I, update the target power distribution area total current to the difference, and return to execute an operation of the second distributing module according to the updated target power distribution area total current;
a fourth execution module, configured to determine that the feeder load of the power distribution network is a load calculation value of the M feeder sections if the absolute value Δ I is smaller than the first threshold value ∈;
and the second feeder line load obtaining module is used for obtaining the feeder line load of the power distribution network according to the second load calculation value of the M feeder lines.
According to the method and the device for acquiring the feeder load of the power distribution network based on the sectional measurement, firstly, the total load of a target power distribution area and the actual value of the tail end power of the target power distribution area are calculated according to the acquired measured feeder load data at two ends of the target power distribution area, then, the load value of each branch point of the target power distribution area is calculated according to the total load of the target power distribution area and the acquired estimated value of the load capacity of the branch point, a first load calculation value of M feeder lines in the target power distribution area is acquired, then, the calculated value of the tail end complex power of the target power distribution area is acquired, the calculated value of the tail end complex power of the target power distribution area is compared with the actual value of the tail end complex power of the target power distribution area, the absolute value of the difference between the two values is calculated, iteration is continuously carried out through a preset threshold value until the absolute value is smaller than the preset threshold value, so that the continuously adjusted feeder load is acquired, and the load acquisition precision of the feeder line is greatly improved.
Drawings
In order to more clearly describe the technical solution of the present application, the drawings required to be used in the embodiments will be briefly described below, and it is obvious for those skilled in the art to obtain other drawings without inventive labor.
Fig. 1 is a schematic diagram of a power distribution automation system as disclosed in the prior art;
fig. 2 is a schematic workflow diagram of a method for acquiring feeder load of a distribution network based on sectional measurement according to an embodiment of the present invention;
fig. 3 is a schematic view of an application scenario of a power distribution network feeder load acquisition method based on sectional measurement according to an embodiment of the present invention;
fig. 4 is a flowchart of another method for acquiring feeder load of distribution network based on segmented measurement according to an embodiment of the present invention
Fig. 5 is a flowchart illustrating a method for acquiring feeder load of a power distribution network based on segmented measurement according to another embodiment of the present disclosure;
fig. 6 is a schematic structural diagram of a feeder load acquisition device for a power distribution network based on segmented measurement according to an embodiment of the present invention;
fig. 7 is a schematic structural diagram of another distribution network feeder load acquisition device based on segmented measurement according to an embodiment of the present invention.
Detailed Description
In order to improve the accuracy of acquiring the feeder load of the power distribution network in the prior art, the invention discloses a method and a device for acquiring the feeder load of the power distribution network based on sectional measurement through the following embodiments.
In order to make the aforementioned objects, features and advantages of the present application more comprehensible, the present application is described in further detail with reference to the accompanying drawings and the detailed description.
Referring to a work flow diagram shown in fig. 2, a method for acquiring a feeder load of a power distribution network based on segmented measurement disclosed by the embodiment of the invention comprises the following steps:
step S101, obtaining head end measurement data and tail end measurement data of a target power distribution area, wherein the target power distribution area is any one of power distribution areas needing to obtain feeder loads in a power distribution network, the target power distribution area comprises M sections of feeders, the head end measurement data of the target power distribution area comprises a head end voltage measurement value, a head end active power measurement value and a head end reactive power measurement value, and the tail end measurement data of the target power distribution area comprises a tail end active power measurement value and a tail end reactive power measurement value.
Step S102, calculating a total load of the target power distribution area and a terminal complex power actual value of the target power distribution area according to the head end measurement data and the terminal measurement data of the target power distribution area, wherein the total load of the target power distribution area comprises a total active power value and a total reactive power value of the target power distribution area.
Step S103, obtaining an estimated value of a branch point load capacity of the target power distribution area, and obtaining each branch point load value of the target power distribution area according to a total load of the target power distribution area and the estimated value of the branch point load capacity, where the branch point is a node of a load connected to a terminal of each feeder line in the M feeder lines, the branch point load is a load connected to a terminal of each feeder line, each branch point load value includes an active power calculated value and a reactive power calculated value, and a complex power calculated value of each branch point load is obtained according to the active power calculated value and the reactive power calculated value of each branch point load.
Step S104, obtaining first load calculation values of M feeder sections in the target power distribution area according to the head end measurement data of the target power distribution area and each branch point load value of the target power distribution area, where the first load calculation values include a head end load calculation value and a tail end load calculation value, the head end load calculation values include a head end current calculation value, a head end voltage calculation value and a head end complex power calculation value, and the tail end load calculation values include a tail end current calculation value, a tail end voltage calculation value and a tail end complex power calculation value.
Step S105, obtaining an absolute value Δ S of a difference between the calculated value of the terminal complex power in the target power distribution area and the actual value of the terminal complex power in the target power distribution area, where the calculated value of the terminal complex power in the target power distribution area is a calculated value of the terminal complex power of the last feeder in the M feeder sections.
Step S106, determining whether the absolute value Δ S is smaller than a preset first threshold value ∈, if not, performing the operation of step S107, and if so, performing the operation of step S108.
And step S107, if the absolute value delta S is greater than or equal to the first threshold epsilon, acquiring a difference value between the total load of the target power distribution area and the absolute value delta S, updating the total load of the target power distribution area into the difference value, and returning to execute the operation of the step S103 according to the updated total load of the target power distribution area.
And step S108, if the absolute value delta S is smaller than the first threshold epsilon, determining the feeder load of the power distribution network as a first load calculation value of the M feeder sections.
Step S109, obtaining the feeder load of the distribution network according to the first load calculation value of the M feeder sections.
According to the method and the device for acquiring the feeder load of the power distribution network based on the sectional measurement, firstly, the total load of a target power distribution area and the actual value of the tail end power of the target power distribution area are calculated according to the acquired measured feeder load data at two ends of the target power distribution area, then, the load value of each branch point of the target power distribution area is calculated according to the total load of the target power distribution area and the acquired estimated value of the load capacity of the branch point, a first load calculation value of M feeder lines in the target power distribution area is acquired, then, the calculated value of the tail end complex power of the target power distribution area is acquired, the calculated value of the tail end complex power of the target power distribution area is compared with the actual value of the tail end complex power of the target power distribution area, the absolute value of the difference between the calculated value and the actual value of the tail end complex power of the target power distribution area is calculated, the total load of the target power distribution area is iterated continuously through a preset threshold value, the absolute value is reduced gradually until the requirement that the absolute value is smaller than the preset threshold value is met, the continuously adjusted feeder line load is acquired, and the feeder line load acquisition precision is greatly improved.
As an example, in this embodiment or some other embodiments of the present invention, fig. 3 is a schematic view of an application scenario of a feeder load obtaining method for a power distribution network based on section measurement, where the power distribution network in the figure is divided into a power distribution area a, a power distribution area B and other power distribution areas by switching devices, where the switching devices are an egress breaker SW1, a feeder switch SW2 and a feeder switch SW3, the power distribution area a includes M sections of feeders and N loads, and a structure of the power distribution area B is consistent with a structure of the power distribution area a, but a number of feeder sections and a number of loads included in the power distribution area B may not be consistent with the power distribution area a. When the feeder load of the power distribution network is obtained, a certain power distribution area needing to obtain the feeder load can be selected at will to be used as a target power distribution area for calculation.
Further, in step S102, calculating a total load of the target power distribution area and an actual terminal complex power value of the target power distribution area according to the head end measurement data and the terminal measurement data of the target power distribution area, including:
calculating the total load of the target power distribution area according to the measurement value of the active power at the head end, the measurement value of the reactive power at the head end, the measurement value of the active power at the tail end and the measurement value of the reactive power at the tail end of the target power distribution area by the following formula:
P A ＝P 1 -P 2 ；
Q A ＝Q 1 -Q 2 ；
wherein, P A Is the total active power value, Q, of the target power distribution area A Is the total reactive power value, P, of the target distribution area 1 Is the first end active power measurement, Q, of the target distribution area 1 Is a head end reactive power measurement, P, of the target distribution area 2 Is a terminal active power measurement, Q, of the target distribution area 2 Is an end reactive power measurement of the target power distribution area.
According to the terminal active power measurement value and the terminal reactive power measurement value of the target power distribution area, acquiring a terminal complex power actual value of the target power distribution area through the following formula:
S 2 ＝P 2 +jQ 2 ；
wherein S is 2 Is the terminal complex power actual value of the target power distribution area, and j is an imaginary unit.
In addition, in step S103, a branch point load capacity estimation value of the target power distribution area is obtained, and each branch point load value of the target power distribution area is obtained according to the total load of the target power distribution area and the branch point load capacity estimation value, where the branch point is a node of an incoming load at an end of each feeder line in the M feeder lines, the branch point load is an incoming load at an end of each feeder line, and each branch point load value includes an active power calculation value and a reactive power calculation value, and a complex power calculation value of each branch point load is obtained according to the active power calculation value and the reactive power calculation value of each branch point load. As an example, in this or other embodiments of the invention, the first two branch point load values of the target power distribution area are obtained according to the following formula:
P L1 ＝P A ·S BL1 /(S BL1 +S BL2 )；
Q L1 ＝Q A ·S BL1 /(S BL1 +S BL2 )；
P L2 ＝P A ·S BL2 /(S BL1 +S BL2 )；
Q L2 ＝Q A ·S BL2 /(S BL1 +S BL2 )；
wherein, P L1 Is the calculated value of the active power of the branch point load of the first section of the feeder line in the target distribution area, Q L1 Is a calculated value of reactive power, P, of a branch point load of a first section of feeder line in said target distribution area L2 Is the calculated value of the active power, Q, of the branch point load of the second section of the feeder line in the target distribution area L2 Is a calculated reactive power value of a branch point load of a second feeder in said target distribution area, S BL1 Is an estimate of the branch point load capacity of the first feeder section in said target distribution area, S BL2 Is an estimate of the branch point load capacity, P, of a second feeder line in said target distribution area A Is the total active power value, Q, of the target power distribution area A Is the total reactive power value of the target power distribution area.
As an example, in this embodiment or other embodiments of the present invention, the complex power calculated value of the first two branch point loads is obtained according to the real power calculated value and the reactive power calculated value of the first two branch point loads by the following formula:
S L1 ＝P L1 +jQ L1 ；
S L2 ＝P L2 +jQ L2 ；
wherein S is L1 Is a complex power calculation value of a branch point load of a first section of a feeder line in the target power distribution area, S L2 Is a complex power calculation value of a branch point load of a second section of the feeder line in the target power distribution area, j is a virtualNumber units.
When the load values of other branch points in the target power distribution area are obtained, the calculation can be performed according to the total load of the target power distribution area and the estimated load capacity value corresponding to the branch point by the same method.
Further, in step S104, obtaining first calculated load values of M feeder lines in the target power distribution area according to the head end measurement data of the target power distribution area and each branch point load value of the target power distribution area, including:
and acquiring a terminal load calculation value of the first section of feeder line and a head load calculation value of the second section of feeder line in the target power distribution area according to the head measurement data of the target power distribution area and the branch point load value of the first section of feeder line in the target power distribution area.
And acquiring a terminal load calculation value of the a-th section feeder line and a head load calculation value of the (a + 1) th section feeder line in the target power distribution area according to the head load calculation value of the a-th section feeder line in the target power distribution area and the branch point load value of the a-th section feeder line in the target power distribution area until acquiring a terminal load calculation value of the M-th section feeder line, wherein a is a positive integer smaller than M.
Further, obtaining a terminal load calculation value of the first section of feeder line and a head load calculation value of the second section of feeder line in the target power distribution area according to the head measurement data of the target power distribution area and the branch point load value of the first section of feeder line in the target power distribution area, includes:
according to the head end measurement data of the target power distribution area, acquiring a head end complex power actual value of the target power distribution area through the following formula:
S 1 ＝P 1 +jQ 1 ；
wherein S is 1 Is the head end complex power actual value, P, of the target distribution area 1 Is the first end active power measurement, Q, of the target distribution area 1 Is a head end reactive power measurement value of the target distribution area, and j is an imaginary unit.
According to the head end voltage measurement value of the target power distribution area and the head end complex power actual value of the target power distribution area, obtaining a current calculation value of a first section of feeder line in the target power distribution area through the following formula:
Figure GDA0003331480490000121
wherein the content of the first and second substances,
Figure GDA0003331480490000131
is a calculated value of the current of the first section of the feeder line in the target distribution area,
Figure GDA0003331480490000132
is a head end voltage measurement of the target power distribution area.
Acquiring an impedance value of each feeder line section in the target power distribution area, and acquiring a voltage calculation value of a branch point of a first feeder line section in the target power distribution area according to the impedance value of the first feeder line section in the target power distribution area, a current calculation value of the first feeder line section in the target power distribution area and a head end voltage measurement value of the target power distribution area by the following formula:
Figure GDA0003331480490000133
wherein, the first and the second end of the pipe are connected with each other,
Figure GDA0003331480490000134
is a calculated voltage value of a branch point of a first section of the feeder line in the target distribution area, Z LN1 Is the impedance value of the first section of the feeder line in the target power distribution area.
According to the voltage calculated value of the branch point of the first section of the feeder line in the target power distribution area and the current calculated value of the first section of the feeder line in the target power distribution area, acquiring a terminal complex power calculated value of the first section of the feeder line in the target power distribution area through the following formula:
Figure GDA0003331480490000135
wherein S is LN1 ' is a calculated complex power at the end of the first section of the feeder in the target distribution area.
Acquiring a complex power calculated value of a branch point load of a first section of feeder line in the target power distribution area, and acquiring a current calculated value of the branch point load of the first section of feeder line in the target power distribution area according to the complex power calculated value of the branch point load of the first section of feeder line in the target power distribution area and a voltage calculated value of the branch point of the first section of feeder line in the target power distribution area by the following formula:
Figure GDA0003331480490000136
wherein, the first and the second end of the pipe are connected with each other,
Figure GDA0003331480490000137
is the calculated value of the current of the branch point load of the first section of the feeder line in the target distribution area, S L1 Is a complex power calculation of the branch point load of the first section of the feeder line in the target distribution area.
According to the current calculated value of the first section of feeder line in the target power distribution area and the current calculated value of the branch point load of the first section of feeder line in the target power distribution area, obtaining the current calculated value of the second section of feeder line in the target power distribution area through the following formula:
Figure GDA0003331480490000138
wherein the content of the first and second substances,
Figure GDA0003331480490000139
is a calculated current value of the second section of the feeder line in the target power distribution area.
According to the calculated current value of the second section of feeder line in the target power distribution area and the calculated voltage value of the branch point of the first section of feeder line in the target power distribution area, the calculated first-end complex power value of the second section of feeder line in the target power distribution area is obtained through the following formula:
Figure GDA0003331480490000141
wherein S is LN2 Is a first-end complex power calculated value of a second section of the feeder line in the target power distribution area.
Fig. 4 is disclosed in the embodiment of the present invention for the solutions disclosed in step S101 to step S109. The 3 dotted line frames in the figure divide the work flow of acquiring the feeder load of the whole power distribution network into 3 stages, wherein the first stage is a flow of acquiring the load of a target feeder, the second stage is a flow of acquiring the feeder load of a target power distribution area, and the third stage is a flow of acquiring the feeder load of the whole power distribution network. Through the work flow of fig. 4, the feeder load of the whole distribution network can be completely calculated.
Further, referring to a work flow chart shown in fig. 5, in the method for acquiring a feeder load of a power distribution network based on a segmented measurement disclosed in the embodiment of the present invention, when there is no power measurement data in measurement data at two ends of the target power distribution area, the method for acquiring a feeder load of a power distribution network further includes the following steps:
step S201, obtaining head end measurement data and tail end measurement data of the target power distribution area, where the measurement data are a current measurement value and a voltage measurement value.
Step S202, calculating the total current of the target power distribution area according to the head end current measurement value and the tail end current measurement value of the target power distribution area.
Step S203, obtaining an estimated value of the branch point load capacity of the target power distribution area, and distributing a current value of each branch point load of the target power distribution area according to the total current of the target power distribution area and the estimated value of the branch point load capacity.
Step S204, obtaining a second load calculation value of M feeder sections in the target power distribution area according to the head end measurement data of the target power distribution area and the current value of each branch point load of the target power distribution area, where the second load calculation value includes a current calculation value and a voltage calculation value.
Step S205, obtaining an absolute value Δ I of a difference between a calculated value of the terminal current of the target power distribution area and a measured value of the terminal current of the target power distribution area, where the calculated value of the terminal current of the target power distribution area is a calculated value of the current of a last feeder in the M feeder segments.
In step S206, it is determined whether the absolute value Δ I is smaller than a preset first threshold value ∈.
Step S207, if the absolute value Δ I is greater than or equal to the first threshold value ∈, obtaining a difference between the target power distribution area total current and the absolute value Δ I, updating the target power distribution area total current to the difference, and returning to execute the operation of step S203 according to the updated target power distribution area total current.
Step S208, if the absolute value Δ I is smaller than the first threshold value epsilon, determining that the feeder load of the distribution network is the load calculation value of the M feeder sections.
And step S209, acquiring the feeder load of the power distribution network according to the second load calculation value of the M feeder sections.
Further, in step S202, the calculating a total current of the target power distribution area according to the head end current measurement value and the tail end current measurement value of the target power distribution area includes:
obtaining the total current of the target power distribution area according to the head end current measurement value and the tail end current measurement value of the target power distribution area through the following formula:
I A ＝I 1 -I 2 ；
wherein, I A Is the target distribution area total current, I 1 Is a head end current measurement, I, of the target distribution area 2 Is an end current measurement of the target power distribution zone.
Further, in step S203, an estimated value of the branch point load capacity of the target power distribution area is obtained, and a current value of each branch point load of the target power distribution area is distributed according to the total current of the target power distribution area and the estimated value of the branch point load capacity. As an example, in this or other embodiments of the present invention, the current values of the first two branch point loads of the target power distribution area are obtained according to the following formula:
Figure GDA0003331480490000151
Figure GDA0003331480490000152
wherein, the first and the second end of the pipe are connected with each other,
Figure GDA0003331480490000153
is the current value of the branch point load of the first section of the feeder line in said target distribution area,
Figure GDA0003331480490000154
is the current value, I, of the branch point load of the second section of the feeder line in the target distribution area A Is the target distribution area total current, S BL1 Is an estimate of the branch point load capacity of the first feeder section in said target distribution area, S BL2 Is an estimate of the branch point load capacity of the second feeder in the target distribution area.
Further, in step S204, the obtaining a second load calculation value of M feeder lines in the target power distribution area according to the head end measurement data of the target power distribution area and the current value of each branch point load in the target power distribution area includes:
and acquiring a second load calculation value of a second section of feeder line in the target power distribution area according to the head end measurement data of the target power distribution area and the current value of the branch point load of the first section of feeder line in the target power distribution area.
And acquiring a second load calculation value of the (a + 1) th feeder line in the target power distribution area according to the second load calculation value of the a-th feeder line in the target power distribution area and the current value of the branch point load of the a-th feeder line in the target power distribution area until acquiring a second load calculation value of the M-th feeder line, wherein a is a positive integer smaller than M.
Further, the obtaining a second load calculation value of a second section of feeder line in the target power distribution area according to the head end measurement data of the target power distribution area and the current value of the branch point load of the first section of feeder line in the target power distribution area includes:
acquiring the resistance value of each section of feeder line in the target power distribution area, and acquiring a voltage calculation value of a branch point of the first section of feeder line in the target power distribution area according to the resistance value of the first section of feeder line in the target power distribution area, the head end current measurement value and the head end voltage measurement value of the target power distribution area by the following formula:
Figure GDA0003331480490000161
wherein, the first and the second end of the pipe are connected with each other,
Figure GDA0003331480490000162
is a calculated voltage value of a branch point of a first section of the feeder line in the target distribution area,
Figure GDA0003331480490000163
is a head end voltage measurement, R, of the target distribution area LN1 Is the resistance value of the first segment of the feeder line in the target power distribution area,
Figure GDA0003331480490000164
is a head end current measurement value for the target power distribution area.
According to the head end current measurement value of the target power distribution area and the current value of the branch point load of the first section of feeder line in the target power distribution area, obtaining the current calculation value of the second section of feeder line in the target power distribution area through the following formula:
Figure GDA0003331480490000165
wherein the content of the first and second substances,
Figure GDA0003331480490000166
is a calculated value of the current of the second section of the feeder line in the target power distribution area,
Figure GDA0003331480490000167
is the current value of the branch point load of the first section of the feeder line in the target distribution area.
In step S104, if the second load calculation value of the M feeder lines in the target power distribution area is obtained and a reactive power value needs to be calculated, a fixed power factor may be obtained, and then the reactive power value is calculated according to the fixed power factor.
The following are embodiments of the apparatus of the present invention that may be used to perform embodiments of the method of the present invention. For details which are not disclosed in the embodiments of the apparatus of the present invention, reference is made to the embodiments of the method of the present invention.
Accordingly, another embodiment of the present invention discloses a distribution network feeder load obtaining device based on sectional measurement, referring to the schematic structural diagram shown in fig. 6, the distribution network feeder load obtaining device based on sectional measurement includes: the feeder load measurement system comprises a first measurement data acquisition module 10, a total load calculation module 20, a first distribution module 30, a first load calculation value acquisition module 40, a first absolute value acquisition module 50, a first judgment module 60, a first execution module 70, a second execution module 80 and a first feeder load acquisition module 90.
The first measurement data acquisition module 10 is configured to acquire head end measurement data and tail end measurement data of a target power distribution area, where the target power distribution area is any one of power distribution areas in which feeder loads need to be acquired in a power distribution network, the target power distribution area includes M sections of feeders, the head end measurement data of the target power distribution area includes a head end voltage measurement value, a head end active power measurement value and a head end reactive power measurement value, and the tail end measurement data of the target power distribution area includes a tail end active power measurement value and a tail end reactive power measurement value.
The total load calculation module 20 is configured to obtain a total load of the target power distribution area and a terminal complex power actual value of the target power distribution area according to the head-end measurement data and the terminal measurement data of the target power distribution area, where the total load of the target power distribution area includes a total active power value and a total reactive power value of the target power distribution area.
The first distribution module 30 is configured to obtain an estimated value of a branch point load capacity of the target power distribution area, and obtain each branch point load value of the target power distribution area according to a total load of the target power distribution area and the estimated value of the branch point load capacity, where the branch point is a node at which a load is connected to an end of each feeder line in the M feeder lines, the branch point load is a load connected to an end of each feeder line, each branch point load value includes an active power calculated value and a reactive power calculated value, and a complex power calculated value of each branch point load is obtained according to the active power calculated value and the reactive power calculated value of each branch point load.
The first load calculation value obtaining module 40 is configured to obtain first load calculation values of M feeder sections in the target power distribution area according to the head end measurement data of the target power distribution area and each branch point load value of the target power distribution area, where the first load calculation values include a head end load calculation value and a tail end load calculation value, the head end load calculation values include a head end current calculation value, a head end voltage calculation value, and a head end complex power calculation value, and the tail end load calculation values include a tail end current calculation value, a tail end voltage calculation value, and a tail end complex power calculation value.
The first absolute value obtaining module 50 is configured to obtain an absolute value Δ S of a difference between a terminal complex power calculated value of the target power distribution area and a terminal complex power actual value of the target power distribution area, where the terminal complex power calculated value of the target power distribution area is a terminal complex power calculated value of a last feeder line in the M feeder lines.
The first determining module 60 is configured to determine whether the absolute value Δ S is smaller than a preset first threshold value epsilon.
The first executing module 70 is configured to, if the absolute value Δ S is greater than or equal to the first threshold value epsilon, obtain a difference between the total load of the target power distribution area and the absolute value Δ S, update the total load of the target power distribution area to the difference, and return to execute the operation of the first distributing module 30 according to the updated total load of the target power distribution area.
The second executing module 80 is configured to determine that the feeder load of the power distribution network is the load calculation value of the M feeder sections if the absolute value Δ S is smaller than the first threshold value epsilon.
The first feeder load obtaining module 90 is configured to obtain a feeder load of the power distribution network according to the first load calculation value of the M feeder sections.
Further, referring to the schematic structural diagram shown in fig. 7, in the feeder load acquisition device for a power distribution network based on segmented measurement disclosed in the embodiment of the present invention, when there is no power measurement data in measurement data at two ends of the target power distribution area, the feeder load acquisition device for a power distribution network further includes: the second measurement data acquiring module 100, the total current calculating module 200, the second distributing module 300, the second load calculation value acquiring module 400, the second absolute value acquiring module 500, the second determining module 600, the third executing module 700, the fourth executing module 800, and the second feeder load acquiring module 900.
The second measurement data acquiring module 100 is configured to acquire head end measurement data and tail end measurement data of the target power distribution area, where the measurement data are a current measurement value and a voltage measurement value.
The total current calculating module 200 is configured to calculate a total current of the target power distribution area according to the head end current measurement value and the tail end current measurement value of the target power distribution area.
The second allocating module 300 is configured to obtain an estimated value of the branch point load capacity of the target power distribution area, and allocate a current value of each branch point load of the target power distribution area according to the total current of the target power distribution area and the estimated value of the branch point load capacity.
The second load calculation value obtaining module 400 is configured to obtain second load calculation values of M feeder lines in the target power distribution area according to the head end measurement data of the target power distribution area and the current value of each branch point load of the target power distribution area, where the second load calculation values include a current calculation value and a voltage calculation value.
The second absolute value obtaining module 500 is configured to obtain an absolute value Δ I of a difference between a calculated value of a terminal current of the target power distribution area and a measured value of the terminal current of the target power distribution area, where the calculated value of the terminal current of the target power distribution area is a calculated value of a current of a last feeder line of the M feeder lines.
The second determining module 600 is configured to determine whether the absolute value Δ I is smaller than a preset first threshold value epsilon.
The third executing module 700 is configured to, if the absolute value Δ I is greater than or equal to the first threshold value epsilon, obtain a difference between the total current of the target power distribution area and the absolute value Δ I, update the total current of the target power distribution area to the difference, and return to execute the operation of the second distributing module 300 according to the updated total current of the target power distribution area.
The fourth executing module 800 is configured to determine that the feeder load of the power distribution network is the load calculation value of the M feeder sections if the absolute value Δ I is smaller than the first threshold value epsilon.
The second feeder load obtaining module 900 is configured to obtain the feeder load of the power distribution network according to the second load calculation value of the M feeder sections.
In specific implementation, the present application further provides a computer storage medium, where the computer storage medium may store a program, and the program may include some or all of the steps in the embodiments of the method provided in the present application when executed. The storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM) or a Random Access Memory (RAM).
Those skilled in the art will clearly understand that the techniques in the embodiments of the present application may be implemented by way of software plus a required general hardware platform. Based on such understanding, the technical solutions in the embodiments of the present application may be essentially implemented or a part contributing to the prior art may be embodied in the form of a software product, which may be stored in a storage medium, such as a ROM/RAM, a magnetic disk, an optical disk, etc., and includes several instructions for enabling a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the method described in the embodiments or some parts of the embodiments of the present application.
The same and similar parts among the various embodiments in this specification may be referred to each other. In particular, as for the apparatus embodiment, since it is substantially similar to the method embodiment, the description is relatively simple, and reference may be made to the description in the method embodiment for relevant points.
The above-described embodiments of the present application do not limit the scope of the present application.

Claims (10)

1. A method for acquiring feeder load of a power distribution network based on segmented measurement is characterized by comprising the following steps:
11 Obtaining head end measurement data and tail end measurement data of a target power distribution area, wherein the target power distribution area is any one of power distribution areas needing to obtain feeder loads in a power distribution network, the target power distribution area comprises M sections of feeders, the head end measurement data of the target power distribution area comprises a head end voltage measurement value, a head end active power measurement value and a head end reactive power measurement value, and the tail end measurement data of the target power distribution area comprises a tail end active power measurement value and a tail end reactive power measurement value;
12 Calculating a total load of the target power distribution area and a terminal complex power actual value of the target power distribution area according to the head end measurement data and the terminal measurement data of the target power distribution area, wherein the total load of the target power distribution area comprises a total active power value and a total reactive power value of the target power distribution area;
13 Obtaining an estimated value of a load capacity of a branch point of the target power distribution area, and obtaining a load value of each branch point of the target power distribution area according to a total load of the target power distribution area and the estimated value of the load capacity of the branch point, where the branch point is a node of a load connected to an end of each feeder line in the M feeder lines, the load value of the branch point is a load connected to an end of each feeder line, the load value of each branch point includes a calculated value of active power and a calculated value of reactive power, and the calculated value of complex power of each branch point is obtained according to the calculated value of active power and the calculated value of reactive power of each branch point;
14 Obtaining first calculated load values for M feeder sections in the target power distribution area based on the head end measured data for the target power distribution area and each branch point load value for the target power distribution area, wherein the first calculated load values include a head end calculated load value and a tail end calculated load value, the head end calculated load values include a head end calculated current value, a head end calculated voltage value and a head end calculated complex power value, and the tail end calculated load values include a tail end calculated current value, a tail end calculated voltage value and a tail end calculated complex power value;
15 Obtaining an absolute value deltaS of a difference value between a terminal complex power calculated value of the target power distribution area and a terminal complex power actual value of the target power distribution area, wherein the terminal complex power calculated value of the target power distribution area is a terminal complex power calculated value of the last feeder line in the M feeder lines;
16 ) determining whether the absolute value Δ S is smaller than a preset first threshold value epsilon;
17 If the absolute value Δ S is greater than or equal to the first threshold value epsilon, obtaining a difference value between the total load of the target power distribution area and the absolute value Δ S, updating the total load of the target power distribution area to the difference value, and returning to execute the operation of the step 13) according to the updated total load of the target power distribution area;
18 If the absolute value deltas is smaller than the first threshold epsilon, determining the feeder load of the distribution network as a first load calculation value of the M feeder sections;
19 Obtaining the feeder load of the distribution network according to the first load calculation value of the M feeder sections.
2. The method of claim 1, wherein calculating the target distribution area total load and the target distribution area terminal complex power actual value based on the head end measured data and the terminal measured data of the target distribution area comprises:
calculating the total load of the target power distribution area according to the measurement value of the active power at the head end, the measurement value of the reactive power at the head end, the measurement value of the active power at the tail end and the measurement value of the reactive power at the tail end of the target power distribution area by the following formula:
P A ＝P 1 -P 2 ；
Q A ＝Q 1 -Q 2 ；
wherein, P A Is the total active power value, Q, of the target power distribution area A Is the total reactive power value, P, of the target distribution area 1 Is a measurement value, Q, of the active power at the head end of the target distribution area 1 Is a head end reactive power measurement, P, of the target distribution area 2 Is a terminal active power measurement, Q, of the target distribution area 2 Is an end reactive power measurement value for the target power distribution zone;
according to the terminal active power measurement value and the terminal reactive power measurement value of the target power distribution area, acquiring a terminal complex power actual value of the target power distribution area through the following formula:
S 2 ＝P 2 +jQ 2 ；
wherein S is 2 Is the terminal complex power actual value of the target power distribution area, and j is an imaginary unit.
3. The method of claim 1, wherein obtaining the first calculated load values for M feeder segments in the target distribution area based on the head end measurement data for the target distribution area and the load values at each branch point of the target distribution area comprises:
acquiring a terminal load calculation value of a first section of feeder line and a head end load calculation value of a second section of feeder line in the target power distribution area according to the head end measurement data of the target power distribution area and the branch point load value of the first section of feeder line in the target power distribution area;
and acquiring a terminal load calculation value of the a-th section feeder line and a head load calculation value of the (a + 1) th section feeder line in the target power distribution area according to the head load calculation value of the a-th section feeder line in the target power distribution area and the branch point load value of the a-th section feeder line in the target power distribution area until acquiring a terminal load calculation value of the M-th section feeder line, wherein a is a positive integer smaller than M.
4. The method of claim 3, wherein obtaining the calculated end load value for the first section of the feeder and the calculated head load value for the second section of the feeder in the target distribution area based on the measured head end data for the target distribution area and the branch point load value for the first section of the feeder in the target distribution area comprises:
according to the head end measurement data of the target power distribution area, acquiring a head end complex power actual value of the target power distribution area through the following formula:
S 1 ＝P 1 +jQ 1 ；
wherein S is 1 Is the actual value of the head-end complex power of the target distribution area, j is an imaginary unit, P 1 Is the first end active power measurement, Q, of the target distribution area 1 Is a head end reactive power measurement value of the target power distribution area;
obtaining a current calculation value of a first section of feeder line in the target power distribution area according to the head end voltage measurement value of the target power distribution area and the head end complex power actual value of the target power distribution area by the following formula:
Figure FDA0003331480480000031
wherein the content of the first and second substances,
Figure FDA0003331480480000032
is a calculated value of the current of the first section of the feeder line in the target distribution area,
Figure FDA0003331480480000033
is a head end voltage measurement of the target power distribution area;
acquiring an impedance value of each feeder in the target power distribution area, and acquiring a voltage calculation value of a branch point of a first feeder in the target power distribution area according to the impedance value of the first feeder in the target power distribution area, a current calculation value of the first feeder in the target power distribution area, and a voltage measurement value of a head end of the target power distribution area by the following formula:
Figure FDA0003331480480000034
wherein the content of the first and second substances,
Figure FDA0003331480480000035
is a calculated voltage value, Z, of a branch point of a first section of the feeder line in the target distribution area LN1 Is an impedance value of a first section of feeder line in the target power distribution area;
according to the voltage calculation value of the branch point of the first section of the feeder line in the target power distribution area and the current calculation value of the first section of the feeder line in the target power distribution area, acquiring a terminal complex power calculation value of the first section of the feeder line in the target power distribution area through the following formula:
Figure FDA0003331480480000036
wherein S is LN1 ' is aCalculating the terminal complex power of a first section of feeder line in the target power distribution area;
obtaining a complex power calculation value of a branch point load of a first feeder line section in the target power distribution area, and obtaining a current calculation value of the branch point load of the first feeder line section in the target power distribution area according to the complex power calculation value of the branch point load of the first feeder line section in the target power distribution area and a voltage calculation value of the branch point of the first feeder line section in the target power distribution area by the following formula:
Figure FDA0003331480480000037
wherein the content of the first and second substances,
Figure FDA0003331480480000038
is the calculated value of the current of the branch point load of the first section of the feeder line in the target distribution area, S L1 Is a complex power calculation value of a branch point load of a first section of feeder line in the target power distribution area;
according to the current calculated value of the first section of feeder line in the target power distribution area and the current calculated value of the branch point load of the first section of feeder line in the target power distribution area, obtaining the current calculated value of the second section of feeder line in the target power distribution area through the following formula:
Figure FDA0003331480480000041
wherein the content of the first and second substances,
Figure FDA0003331480480000042
is the current calculated value of the second section of feeder line in the target power distribution area;
according to the calculated current value of the second section of the feeder line in the target power distribution area and the calculated voltage value of the branch point of the first section of the feeder line in the target power distribution area, acquiring a calculated first-end complex power value of the second section of the feeder line in the target power distribution area through the following formula:
Figure FDA0003331480480000043
wherein S is LN2 Is a first-end complex power calculated value of a second section of the feeder line in the target power distribution area.
5. The method of claim 1, wherein when there is no power measurement data measured across the target power distribution area, the method further comprises:
51 Obtaining head end measurement data and tail end measurement data of the target power distribution area, wherein the measurement data are current measurement values and voltage measurement values;
52 Calculating a total current of the target power distribution area according to the head end current measurement value and the tail end current measurement value of the target power distribution area;
53 Obtaining an estimated value of the branch point load capacity of the target power distribution area, and distributing a current value of each branch point load of the target power distribution area according to the total current of the target power distribution area and the estimated value of the branch point load capacity;
54 Obtaining second load calculation values of M feeder lines in the target power distribution area according to the head end measurement data of the target power distribution area and the current value of each branch point load of the target power distribution area, wherein the second load calculation values include a current calculation value and a voltage calculation value;
55 Obtaining an absolute value Δ I of a difference between a calculated value of a terminal current of the target power distribution area and a measured value of a terminal current of the target power distribution area, wherein the calculated value of the terminal current of the target power distribution area is a calculated value of a current of a last feeder line of the M feeder lines;
56 ) determining whether the absolute value Δ I is smaller than a preset first threshold value epsilon;
57 If the absolute value Δ I is greater than or equal to the first threshold value epsilon, obtaining a difference value between the total current of the target power distribution area and the absolute value Δ I, updating the total current of the target power distribution area to the difference value, and returning to execute the operation of the step 53) according to the updated total current of the target power distribution area;
58 If the absolute value delta I is smaller than the first threshold value epsilon, determining the feeder load of the power distribution network as a load calculation value of the M feeder sections;
59 Obtaining the feeder load of the distribution network according to the second load calculation value of the M feeder sections.
6. The method of claim 5, wherein said calculating said target power distribution area total current from said target power distribution area head end current measurement and tail end current measurement comprises:
obtaining the total current of the target power distribution area according to the head end current measurement value and the tail end current measurement value of the target power distribution area through the following formula:
I A ＝I 1 -I 2 ；
wherein, I A Is the target distribution area total current, I 1 Is a head end current measurement, I, of the target distribution area 2 Is an end current measurement of the target power distribution area.
7. The method of claim 5, wherein obtaining second load calculations for M feeder sections in the target distribution area based on the head end measurement data for the target distribution area and the current values for each branch point load in the target distribution area comprises:
acquiring a second load calculation value of a second section of feeder line in the target power distribution area according to the head end measurement data of the target power distribution area and the current value of the branch point load of the first section of feeder line in the target power distribution area;
and acquiring a second load calculation value of the (a + 1) th feeder line in the target power distribution area according to the second load calculation value of the a-th feeder line in the target power distribution area and the current value of the branch point load of the a-th feeder line in the target power distribution area until acquiring a second load calculation value of the M-th feeder line, wherein a is a positive integer smaller than M.
8. The method of claim 7, wherein obtaining a second calculated load value for a second feeder section in the target distribution area based on head end measurement data for the target distribution area and current values for branch point loads for a first feeder section in the target distribution area comprises:
acquiring the resistance value of each section of feeder line in the target power distribution area, and acquiring a voltage calculation value of a branch point of the first section of feeder line in the target power distribution area according to the resistance value of the first section of feeder line in the target power distribution area, the head end current measurement value and the head end voltage measurement value of the target power distribution area by the following formula:
Figure FDA0003331480480000051
wherein, the first and the second end of the pipe are connected with each other,
Figure FDA0003331480480000052
is a calculated value of the voltage at the branch point of the first stage feeder line in the target distribution area,
Figure FDA0003331480480000053
is a head end voltage measurement, R, of the target distribution area LN1 Is the resistance of the first section of the feed line in the target distribution area,
Figure FDA0003331480480000054
is a head end current measurement value of the target power distribution area;
according to the head end current measurement value of the target power distribution area and the current value of the branch point load of the first section of feeder line in the target power distribution area, obtaining the current calculation value of the second section of feeder line in the target power distribution area through the following formula:
Figure FDA0003331480480000055
wherein, the first and the second end of the pipe are connected with each other,
Figure FDA0003331480480000056
is the calculated current value of the second section of feeder line in the target power distribution area,
Figure FDA0003331480480000057
is the current value of the branch point load of the first section of the feeder line in the target distribution area.
9. The utility model provides a distribution network feeder load acquisition device based on segmentation is measurationed which characterized in that includes:
the first measurement data acquisition module is used for acquiring head end measurement data and tail end measurement data of a target power distribution area, wherein the target power distribution area is any one of power distribution areas needing to acquire feeder loads in a power distribution network, the target power distribution area comprises M sections of feeders, the head end measurement data of the target power distribution area comprises a head end voltage measurement value, a head end active power measurement value and a head end reactive power measurement value, and the tail end measurement data of the target power distribution area comprises a tail end active power measurement value and a tail end reactive power measurement value;
a total load calculation module, configured to obtain a total load of the target power distribution area and an actual terminal complex power value of the target power distribution area according to the head-end measurement data and the terminal measurement data of the target power distribution area, where the total load of the target power distribution area includes a total active power value and a total reactive power value of the target power distribution area;
a first distribution module, configured to obtain an estimated value of a load capacity of a branch point of the target power distribution area, and obtain a load value of each branch point of the target power distribution area according to a total load of the target power distribution area and the estimated value of the load capacity of the branch point, where the branch point is a node of a load connected to an end of each feeder in the M feeder sections, the load value of the branch point is a load connected to an end of each feeder section, and each branch point load value includes an active power calculated value and a reactive power calculated value, and obtain a complex power calculated value of each branch point load according to the active power calculated value and the reactive power calculated value of each branch point load;
a first calculated load value obtaining module, configured to obtain first calculated load values of M feeder segments in the target power distribution area according to the head end measurement data of the target power distribution area and each branch point load value of the target power distribution area, where the first calculated load value includes a head end load calculated value and a tail end load calculated value, the head end load calculated value includes a head end current calculated value, a head end voltage calculated value and a head end complex power calculated value, and the tail end load calculated value includes a tail end current calculated value, a tail end voltage calculated value and a tail end complex power calculated value;
a first absolute value obtaining module, configured to obtain an absolute value Δ S of a difference between a terminal complex power calculated value of the target power distribution area and a terminal complex power actual value of the target power distribution area, where the terminal complex power calculated value of the target power distribution area is a terminal complex power calculated value of a last feeder line in the M feeder lines;
the first judgment module is used for judging whether the absolute value delta S is smaller than a preset first threshold value epsilon or not;
a first execution module, configured to, if the absolute value Δ S is greater than or equal to the first threshold value ∈, obtain a difference between the total load of the target power distribution area and the absolute value Δ S, update the total load of the target power distribution area to the difference, and return to execute an operation of the first distribution module according to the updated total load of the target power distribution area;
a second execution module, configured to determine that the feeder load of the power distribution network is a load calculation value of the M feeder sections if the absolute value Δ S is smaller than the first threshold epsilon;
and the first feeder line load obtaining module is used for obtaining the feeder line load of the power distribution network according to the first load calculation value of the M feeder lines.
10. The apparatus of claim 9, wherein when there is no power measurement data measured across the target power distribution area, the distribution network feeder load acquisition apparatus further comprises:
the second measurement data acquisition module is used for acquiring head end measurement data and tail end measurement data of the target power distribution area, wherein the measurement data are a current measurement value and a voltage measurement value;
the total current calculation module is used for calculating the total current of the target power distribution area according to the head end current measurement value and the tail end current measurement value of the target power distribution area;
the second distribution module is used for acquiring the estimated value of the branch point load capacity of the target power distribution area and distributing the current value of each branch point load of the target power distribution area according to the total current of the target power distribution area and the estimated value of the branch point load capacity;
a second load calculation value obtaining module, configured to obtain second load calculation values of M feeder lines in the target power distribution area according to the data measured at the head end of the target power distribution area and the current value of each branch point load of the target power distribution area, where the second load calculation values include a current calculation value and a voltage calculation value;
a second absolute value obtaining module, configured to obtain an absolute value Δ I of a difference between a calculated value of a terminal current of the target power distribution area and a measured value of the terminal current of the target power distribution area, where the calculated value of the terminal current of the target power distribution area is a calculated value of a current of a last feeder line of the M feeder lines;
the second judgment module is used for judging whether the absolute value delta I is smaller than a preset first threshold value epsilon or not;
a third executing module, configured to, if the absolute value Δ I is greater than or equal to the first threshold value ∈, obtain a difference between the total current of the target power distribution area and the absolute value Δ I, update the total current of the target power distribution area to the difference, and return to execute an operation of the second distributing module according to the updated total current of the target power distribution area;
a fourth execution module, configured to determine that the feeder load of the power distribution network is a load calculation value of the M feeder sections if the absolute value Δ I is smaller than the first threshold value ∈;
and the second feeder line load obtaining module is used for obtaining the feeder line load of the power distribution network according to the second load calculation value of the M feeder lines.
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