CN116388206B - Load shedding calculation method, system and readable medium under transformer N-1 fault - Google Patents
Load shedding calculation method, system and readable medium under transformer N-1 fault Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/12—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load
- H02J3/14—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load by switching loads on to, or off from, network, e.g. progressively balanced loading
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J2203/00—Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
- H02J2203/10—Power transmission or distribution systems management focussing at grid-level, e.g. load flow analysis, node profile computation, meshed network optimisation, active network management or spinning reserve management
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Abstract
The application belongs to the technical field of power distribution network fault recovery, and discloses a load shedding calculation method, a system and a readable medium under a transformer N-1 fault, wherein the calculation method comprises the steps of obtaining networking parameters of a flexible interconnection power distribution network; and determining a load shedding scheme according to the capacity constraint of the flexible interconnection device, the capacity constraint of the transformer, the node voltage constraint of the fault area and the voltage constraint of the non-fault area based on networking parameters. According to the application, the capacity constraint of the transformer, the capacity constraint and the voltage constraint of the flexible interconnection device and the cooperation of the energy storage device and the flexible interconnection device are comprehensively considered, so that the load-shedding scheme is rapidly determined, the power interaction effect of the flexible interconnection device among different areas under the fault condition can be effectively exerted, and the power supply reliability is improved; the method has high calculation speed, can effectively meet the requirement of on-line operation control, considers the importance degree of different loads, can recover the load with high importance degree preferentially, and is suitable for the flexible interconnection distribution network with the distributed power supply and the large-capacity access.
Description
Technical Field
The application belongs to the technical field of power distribution network fault recovery, and particularly relates to a load shedding calculation method, a system and a readable medium under a transformer N-1 fault.
Background
In recent years, the development of modern power electronic control technology accelerates the power electronic process of a power system. The flexible interconnection device is a novel interconnection switch based on the power electronic technology, the power supply mode of the traditional power distribution network of closed loop design and open loop operation is changed, the system has the advantages of an open loop network and a closed loop network, and under the fault working condition of the power distribution network, a non-fault area can supply power for the fault area through the flexible interconnection device, so that the power distribution network has great potential in the aspect of protecting domestic electricity.
The flexible interconnection device is influenced by the capacity of the flexible interconnection device, after a transformer fault occurs, load shedding needs to be carried out on a fault platform area, the flexible interconnection device has high response speed, and the requirement on the calculation speed of the load shedding is high. At present, the existing load shedding calculation method mainly aims at the traditional alternating current power distribution network, the operation characteristics of the flexible interconnection power distribution network are not considered, and meanwhile, the calculation speed is difficult to meet the operation requirements of the flexible interconnection device.
Disclosure of Invention
Aiming at the problems, the application provides a load shedding calculation method, a system and a readable medium under the condition of a transformer N-1 fault, which adopt the following technical scheme:
a load shedding calculation method under a transformer N-1 fault comprises the following steps: acquiring networking parameters of the flexible interconnection power distribution network; and determining a load shedding scheme according to the capacity constraint of the flexible interconnection device, the capacity constraint of the transformer, the node voltage constraint of the fault area and the voltage constraint of the non-fault area based on networking parameters.
Further, the networking parameters comprise a topological structure, an importance level of a load, a line parameter and a load parameter of the flexible interconnection power distribution network.
Further, based on networking parameters, determining a load shedding scheme according to flexible interconnection device capacity constraint, transformer capacity constraint, fault area node voltage constraint and non-fault area voltage constraint, comprising the following steps:
determining a first load scheme according to capacity constraint of the flexible interconnection device based on networking parameters;
determining a second cut-load scheme according to the first cut-load scheme and the transformer capacity constraint;
determining a third load shedding scheme according to the second load shedding scheme and the node voltage constraint of the fault area;
and determining a final cut load scheme according to the third cut load scheme and the non-fault zone voltage constraint.
Further, based on networking parameters, determining a first load-shedding scheme according to capacity constraints of the flexible interconnection device, including the following steps:
determining a first all-load capacity of a fault area according to SOP capacity constraint based on networking parameters;
when the first cut load capacity is a positive value, starting from the outlet of the fault side transformer, cutting off the load according to the importance level sequence of the load until the cut load capacity reaches the first cut load capacity.
Further, based on the networking parameters, determining a first load-shedding scheme according to capacity constraint of the flexible interconnection device, and further comprising the following steps:
when the first load capacity is negative, calculating from the outlet of the fault side transformer, and determining the distributed power supply needing to be cut off.
Further, determining a second cut-load scheme based on the first cut-load scheme and the transformer capacity constraint, comprising the steps of:
determining a second load shedding capacity of the fault transformer area according to the capacity of the non-fault transformer and the capacity of the SOP based on the first load shedding scheme;
when the second cut load capacity is a positive value, starting from the outlet of the fault side transformer, cutting off the load according to the importance level sequence of the load until the cut load capacity reaches the second cut load capacity.
Further, determining a second cut-load scheme based on the first cut-load scheme and the transformer capacity constraint, further comprising the steps of:
when the second cut load capacity is a negative value, starting calculation from the outlet of the fault side transformer, and determining the distributed power supply needing to be cut off.
Further, determining a third load shedding scheme according to the second load shedding scheme and the node voltage constraint of the fault area, wherein the method comprises the following steps of:
determining the sum of all loads of the fault area according to the second load shedding scheme;
when the sum of all loads of the fault area is positive, setting the alternating-current side voltage of the flexible interconnection device as the upper limit value of voltage permission, carrying out load flow calculation on the fault area to obtain the voltage of load nodes of the fault area, if the voltage of all nodes meets the voltage constraint, determining that load shedding is not carried out, if the voltage of the nodes is lower than the lower limit, starting from the tail end of the fault area, cutting off the load according to the importance level sequence of the load, and calculating the voltage amplitude of the out-of-limit node until the voltage of the fault area meets the constraint.
Further, determining a third load shedding scheme according to the second load shedding scheme and the node voltage constraint of the fault area, and further comprising the following steps:
when the sum of all loads of the fault area is negative, setting the alternating-current side voltage of the flexible interconnection device as the lower limit value of voltage permission, carrying out load flow calculation on the fault area to obtain the voltage of load nodes of the fault area, if the voltage of all nodes meets the voltage constraint, determining that the distributed power supply is not required to be cut off, if the node voltage is lower than the lower limit, cutting off the distributed power supply of the tail end node of the fault area, and calculating the voltage amplitude of the out-of-limit node until the voltage of the fault area meets the constraint.
Further, determining a final cut load scheme based on the third cut load scheme and the non-faulty bay voltage constraint, comprising the steps of:
according to a third load shedding scheme of the fault area, the sum of all loads of the fault area is equivalent to the equivalent load of an access node of the alternating current side of the flexible interconnection device, and according to the equivalent load of the access node of the flexible interconnection device, the sum of all loads of the non-fault area is calculated;
and when the sum of all loads of the non-fault area is positive, carrying out load flow calculation on the non-fault area to obtain node voltages, if the voltages of all the nodes meet the voltage constraint, determining that load shedding is not carried out, and if the node voltages are lower than the lower limit, starting from the tail end of the fault area, cutting off the loads according to the importance level sequence of the loads, and calculating the voltage amplitude of the out-of-limit node until the voltage of the non-fault area meets the constraint.
Further, determining a final load shedding scheme according to the third load shedding scheme and the non-fault zone voltage constraint, and further comprising the following steps:
and when the sum of all loads of the non-fault area is negative, carrying out load flow calculation on the non-fault area to obtain node voltages, if the voltages of all the nodes meet the voltage constraint, determining that the distributed power supply does not need to be cut off, if the node voltages are lower than the lower limit, cutting off the distributed power supply of the node at the tail end of the fault area, and calculating the out-of-limit node voltage amplitude until the voltage of the non-fault area meets the constraint.
Further, load is cut off according to the importance level sequence of the load, and the voltage amplitude of the out-of-limit node is calculated, comprising the following steps:
and after the load is cut off in the fault area, determining the voltage of the out-of-limit node according to the voltage of the node before the load of the end node is not cut off, the voltage of the end node of the line, the resistance of the line, the reactance of the line, the active power of the end node of the fault area is cut off, and the reactive power of the end node of the fault area is cut off.
Further, the distributed power supply of the terminal node of the fault area is cut off, and the voltage amplitude of the out-of-limit node is calculated, comprising the following steps:
and after the distributed power supplies of the end nodes of the fault area are cut off, determining the voltage of the out-of-limit node according to the voltage of the node before the load of the end node is not cut off, the voltage of the end node of the line, the resistance of the line, the reactance of the line, the active power of the distributed power supplies of the end nodes of the fault area are cut off, and the reactive power of the distributed power supplies of the end nodes of the fault area.
The application also provides a load shedding computing system under the fault of the transformer N-1, which comprises the following components:
the data acquisition module is used for acquiring networking parameters of the flexible interconnection power distribution network;
the data calculation module is used for determining a load shedding scheme according to capacity constraint of the flexible interconnection device, capacity constraint of the transformer, node voltage constraint of the fault area and voltage constraint of the non-fault area based on networking parameters.
Further, the data calculation module is specifically configured to:
determining a first load scheme according to capacity constraint of the flexible interconnection device based on networking parameters;
determining a second cut-load scheme according to the first cut-load scheme and the transformer capacity constraint;
determining a third load shedding scheme according to the second load shedding scheme and the node voltage constraint of the fault area;
and determining a final cut load scheme according to the third cut load scheme and the non-fault zone voltage constraint.
The application also provides a computer readable storage medium, on which a computer program is stored, which when being executed by a processor implements the load shedding calculation method under the fault of the transformer N-1.
The application has the beneficial effects that:
1. according to the application, the capacity constraint of the transformer, the capacity constraint and the voltage constraint of the flexible interconnection device and the cooperation of the energy storage device and the flexible interconnection device are comprehensively considered, so that the load-shedding scheme is rapidly determined, the power interaction effect of the flexible interconnection device among different areas under the fault condition can be effectively exerted, and the power supply reliability is improved; the calculation speed is high, and the requirement of on-line operation control can be effectively met.
2. The application considers the importance degree of different loads and can recover the load with high importance degree preferentially.
3. The application fully considers the situation of bidirectional flow of line power caused by the access of the distributed power supply in the flexible interconnection power distribution network, is suitable for the flexible interconnection power distribution network accessed by the distributed power supply with large capacity, and is effective for the situation that the output power of the distributed power supply is different at different moments in the day.
Additional features and advantages of the application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application. The objectives and other advantages of the application may be realized and attained by the structure particularly pointed out in the written description and drawings.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions of the prior art, the following description will briefly explain the drawings used in the embodiments or the description of the prior art, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 shows a schematic diagram of a transformer failure of a double-ended flexible interconnect distribution network;
FIG. 2 is a schematic flow diagram of a method for calculating a cut load under a fault of a transformer N-1 according to an embodiment of the present application;
FIG. 3 is a detailed flow chart of a method for calculating the cut load under the fault of the transformer N-1 according to the embodiment of the application;
fig. 4 shows a schematic structural diagram of a load shedding computing system under a fault of a transformer N-1 according to an embodiment of the present application.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
It should be noted that the terms "first," "second," and the like herein are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order.
The following is a brief description of a double-ended flexible interconnect power distribution network:
as shown in fig. 1, the double-ended flexible interconnection power distribution network includes a first transformer, a flexible interconnection device, and a second transformer, where the first transformer is connected to a first end of the flexible interconnection device, and a plurality of loads and connection lines are between the first transformer and the first end of the flexible interconnection device, for example, loads N1-N4 are included between the first transformer and the first end of the flexible interconnection device, and lines L1-L4 are included between the first transformer and the first end of the flexible interconnection device; the second transformer is connected to the second end of the flexible interconnect, and a plurality of loads and connection lines are provided between the second transformer and the second end of the flexible interconnect, for example, loads N5-N8, and lines L5-L8 are provided between the second transformer and the second end of the flexible interconnect.
The flexible interconnection device comprises an SOP (soft switching) and a bus, the SOP is used as a connecting switch between the bus and the first transformer and between the bus and the second transformer, and the SOP comprises a first voltage source converter (VSC 1), a capacitor and a second voltage source converter (VSC 2).
For example, as shown in fig. 1, when a second transformer fails, load shedding needs to be performed on a failed transformer area, so that the embodiment of the application provides a load shedding calculation method, a system and a readable medium under the condition that a transformer N-1 fails, which can be applied to a flexible interconnection power distribution network, and improve the power supply reliability of a flexible interconnection device.
As shown in fig. 2, a load shedding calculation method under a fault of a transformer N-1 includes the following steps:
s1, acquiring networking parameters of a flexible interconnection power distribution network of a low-voltage transformer area, wherein the networking parameters comprise a topological structure of the flexible interconnection power distribution network, an importance level of a load, line parameters and load parameters.
S2, determining a load shedding scheme based on networking parameters of the flexible interconnection power distribution network of the low-voltage transformer area, and according to capacity constraint of the flexible interconnection device, capacity constraint of the transformer, node voltage constraint of the fault transformer area and voltage constraint of the non-fault transformer area.
As shown in fig. 3, step S2 includes the steps of:
s21, determining a first load scheme based on networking parameters of a flexible interconnection power distribution network of a low-voltage transformer area according to capacity constraint of a flexible interconnection device, wherein the first load scheme is specifically as follows:
s211, determining first cut-off load capacity of a fault area based on networking parameters of a flexible interconnection power distribution network of a low-voltage area, determining the first cut-off load capacity of the fault area according to SOP capacity constraint, wherein after a transformer N-1 fault occurs in the flexible interconnection power distribution network, SOP supplies power to the fault area, and the transmission power of SOP needs to be smaller than the SOP capacity, and the first cut-off load capacity of the corresponding fault area is as follows:
in the method, in the process of the application,S sop,c to constrain the first tangential load capacity according to the SOP capacity,S sop,max for the capacity of the SOP,S i,load is a nodeiThe value of the power is the load power for the load node, and the value of the power is the negative value of the output power of the distributed power supply for the distributed power supply node;N fau the number of load nodes for the fault area.
S212, when the first load capacity isS sop,c In the case of positive values, in order to ensure that the SOP capacity is not out of limit, it is necessary to cut out the load, calculated from the outlet of the fault side transformer, and cut out the load in order of importance of the load, for example, in the order of three-stage load, two-stage loadAnd sequentially cutting off the loads from the first stage of load until the cut-off load capacity reaches the first cut-off load capacityS sop,c 。
S213, when the first load capacityS sop,c When the power supply is negative, in order to ensure that the SOP capacity is not out of limit, the distributed power supply needs to be cut off, and the distributed power supply needs to be cut off is determined by starting calculation from the outlet of the fault side transformer.
S22, determining a second load shedding scheme according to the first load shedding scheme and the capacity constraint of the transformer, wherein the method comprises the following steps of:
s221, based on a first load switching scheme, determining a second load switching capacity of a fault platform area according to the capacity of a non-fault transformer and the capacity of SOP, wherein after the transformer N-1 of the flexible interconnection power distribution network fails, the non-fault transformer supplies power to a load, the transmission power of the transformer needs to be smaller than the capacity of the transformer, and the second load switching capacity of the corresponding fault platform area is as follows:
in the method, in the process of the application,S tr,c a second cut load capacity constrained according to the capacity of the non-faulty transformer;N unfau the number of load nodes for the non-faulty zone,S tr,max for the capacity of the non-faulty transformer,representing the number of nodes that are still powered by the failed zone under the first load scenario.
S222, when the second load shedding capacity isS tr,c When the load is positive, in order to ensure that the capacity of the fault side transformer is not out of limit, the load needs to be cut off, the load is cut off according to the sequence of the three-stage load, the two-stage load and the one-stage load from the outlet of the fault side transformer until the cut-off load capacity reaches the second cut-off load capacityS tr,c 。
S223, when the second cutting is negativeCapacity of chargeS tr,c When the power supply is negative, in order to ensure that the capacity of the fault side transformer is not out of limit, the distributed power supply needs to be cut out, and the distributed power supply needs to be cut out is determined by starting calculation from the outlet of the fault side transformer.
S23, determining a third load shedding scheme according to the second load shedding scheme and the node voltage constraint of the fault area, wherein the method comprises the following steps of:
s231, determining the sum of all loads of the fault area according to the second load shedding scheme, and controlling the fault side of the flexible interconnection device by adopting fixed alternating voltage after a transformer at one end of the flexible interconnection power distribution network of the low-voltage area fails. According to the second load shedding scheme of the fault area determined in the step S22, calculating the sum of all loads of the fault areaThe method is characterized by comprising the following steps:
in the method, in the process of the application,N fau,she and cutting the loaded load node set for the fault station.
S232, when the sum of all loads of the fault area S equ,fau And the positive value indicates that the load power is larger than the output power of the distributed power supply, the fault area cannot be subjected to the situation that the voltage is higher than the upper limit, and only the situation that the voltage is lower than the lower limit can be caused. Setting the alternating-current side voltage of the flexible interconnection device as an upper limit value allowed by the voltage, carrying out load flow calculation on a fault platform region to obtain the voltage of load nodes of the fault platform region, if the voltage of all the nodes meets the voltage constraint, no further load shedding is needed, if the voltage of the nodes exceeds the lower limit, loads are shed according to the sequence of three-level loads, two-level loads and one-level loads from the tail end of the fault platform region, and calculating the voltage amplitude of out-of-limit nodes until the voltage of the fault platform region meets the constraint.
After the load is cut off in the fault area, the voltage amplitude of the out-of-limit node is calculated as follows: and determining the voltage of the out-of-limit node according to the voltage of the node before the load of the end node is not cut off, the voltage of the end node of the line, the resistance of the line, the reactance of the line, the active power of the end node of the cut-off fault area and the reactive power of the end node of the cut-off fault area.
For example, within a failed zone, the failed zone end nodes are cut offmOut of limit node after load of (a)iVoltage of (2)The method comprises the following steps:
wherein:load-unresolved node for end nodesiIs a voltage of (2);U j is a circuitjIs a terminal node voltage of (a);R j andX j respectively the linesjResistance and reactance of (a);B i is a nodeiTo the set of lines traversed by the SOP;P m andQ m respectively nodesmThe values of which are positive values.
S232, when the sum of all loads of the fault area S equ,fau And the load power is smaller than the output power of the distributed power supply at the moment, the lower limit situation of the voltage cannot occur in the fault area, and the upper limit situation of the voltage can only occur. Setting the alternating-current side voltage of the flexible interconnection device as a lower limit value allowed by the voltage, carrying out load flow calculation on a fault platform region to obtain the voltage of load nodes of the fault platform region, if the voltage of all nodes meets the voltage constraint, no further cutting of a distributed power supply is needed, if the node voltage is lower than the lower limit, cutting off the distributed power supply of the end node of the fault platform region, and calculating the voltage amplitude of the out-of-limit node until the voltage of the fault platform region meets the constraint.
In the fault area, the distributed power supply of the end node of the fault area is cut off, and the voltage amplitude of the out-of-limit node is calculated as follows: and determining the voltage of the out-of-limit node according to the voltage of the node before the load of the end node is not cut off, the voltage of the end node of the line, the resistance of the line, the reactance of the line, the active power of the distributed power supply for cutting off the end node of the fault area and the reactive power of the distributed power supply for cutting off the end node of the fault area.
For example, within a failed zone, the failed zone end nodes are cut offnAfter distributed power supply of (a), out-of-limit nodeiVoltage of (2)The method comprises the following steps:
in the method, in the process of the application,P n andQ n respectively nodesnThe active output power and the reactive output power of the connected distributed power supply have positive values.
S24, determining a final load shedding scheme according to the third load shedding scheme and the voltage constraint of the non-fault area.
S241, according to the third load shedding scheme of the fault area determined in S23, the sum of all loads of the fault area is equivalent to the equivalent load of the access node of the alternating current side of the flexible interconnection device, and according to the equivalent load of the access node of the flexible interconnection device, the sum of all loads of the non-fault area is calculated:
In the method, in the process of the application,S sop,equ and exchanging the equivalent load of the access node on the side for the flexible interconnection device.
S242, when the sum of all loads of the non-fault area S equ,unfau And the positive value indicates that the load power is larger than the output power of the distributed power supply, the upper voltage limit situation can not occur in the non-fault area, and the lower voltage limit situation can only occur. Carrying out load flow calculation on the non-fault area to obtain node voltage, and if the voltage of all nodes meets the voltage constraint, not needing to go onAnd cutting loads, namely cutting loads according to the sequence of the three-level loads, the two-level loads and the first-level loads from the tail end of the fault area if the node voltage is lower than the lower limit, and calculating the amplitude of the out-of-limit node voltage until the voltage of the non-fault area meets the constraint.
Cutting off end nodes of a fault area in a non-fault areamOut of limit node after load of (a)kVoltage of (2)The method comprises the following steps:
in the method, in the process of the application,load-unresolved node for end nodeskIs a voltage of (2);B sop is the set of lines through which SOP to the transformer pass.
S243, when the sum of all loads of the non-fault area S equ,unfau And the load power is smaller than the output power of the distributed power supply at the moment, the lower voltage limit situation can not occur in the non-fault area, and the upper voltage limit situation can only occur. And carrying out power flow calculation on the non-fault area to obtain node voltages, if the voltages of all the nodes meet the voltage constraint, eliminating the distributed power supply further, if the node voltages are lower than the lower limit, eliminating the distributed power supply of the node at the tail end of the fault area, and calculating the voltage amplitude of the out-of-limit node until the voltage of the non-fault area meets the constraint.
Cutting off end nodes of a fault area in the fault areanAfter distributed power supply of (a), out-of-limit nodekVoltage of (2)The method comprises the following steps:
。
according to the application, through analyzing the operation mode of the double-end flexible interconnection power distribution network transformer after faults, the capacity constraint of the transformer, the capacity constraint and the voltage constraint of the flexible interconnection device are comprehensively considered, and the coordination of the energy storage device and the flexible interconnection device is adopted, so that the load-reducing scheme is rapidly determined. The application effectively plays the role of power mutual aid of the flexible interconnection device among different areas under the fault condition, and improves the power supply reliability; the calculation speed is high, and the requirement of on-line operation control can be effectively met.
Based on the load shedding calculation method under the fault of the transformer N-1, as shown in fig. 4, the embodiment of the application also provides a load shedding calculation system under the fault of the transformer N-1, which comprises a data acquisition module and a data calculation module.
The data acquisition module is used for acquiring networking parameters of the flexible interconnection power distribution network; the data calculation module is used for determining a load shedding scheme according to capacity constraint of the flexible interconnection device, capacity constraint of the transformer, node voltage constraint of the fault area and voltage constraint of the non-fault area based on networking parameters.
The embodiment of the application also provides a computer readable storage medium, on which a computer program is stored, the computer program, when being executed by a processor, realizes the load shedding calculation method under the fault of the transformer N-1.
The computer-readable storage medium may be a non-volatile computer-readable storage medium, which may include, for example, but is not limited to: a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In embodiments of the present application, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
The application fully considers the different output power situations of the distributed power supply and the load in the flexible interconnection power distribution network, is suitable for the flexible interconnection power distribution network with the large-capacity access of the distributed power supply, can effectively exert the power interaction effect of the flexible interconnection device among different areas under the fault condition, and improves the power supply reliability; the calculation speed is high, and the requirement of on-line operation control can be effectively met.
Although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application.
Claims (11)
1. The load shedding calculation method under the fault of the transformer N-1 is characterized by comprising the following steps of:
acquiring networking parameters of the flexible interconnection power distribution network;
based on networking parameters, determining a load shedding scheme according to flexible interconnection device capacity constraint, transformer capacity constraint, fault area node voltage constraint and non-fault area voltage constraint, wherein the load shedding scheme comprises the following steps of: based on networking parameters, determining a first load shedding scheme according to flexible interconnection device capacity constraints comprises: determining a first all-load capacity of a fault area according to SOP capacity constraint based on networking parameters; when the first cut load capacity is a positive value, starting calculation from the outlet of the fault side transformer, cutting off the load according to the importance level sequence of the load until the cut load capacity reaches the first cut load capacity; determining a second cut-load scheme from the first cut-load scheme and the transformer capacity constraint includes: determining a second load shedding capacity of the fault transformer area according to the capacity of the non-fault transformer and the capacity of the SOP based on the first load shedding scheme; when the second cut load capacity is a positive value, starting calculation from the outlet of the fault side transformer, cutting off the load according to the importance level sequence of the load until the cut load capacity reaches the second cut load capacity; determining a third load shedding scheme according to the second load shedding scheme and the fault zone node voltage constraint comprises: determining the sum of all loads of the fault area according to the second load shedding scheme; when the sum of all loads of the fault area is positive, setting the alternating-current side voltage of the flexible interconnection device as the upper limit value of voltage permission, carrying out load flow calculation on the fault area to obtain the voltage of load nodes of the fault area, if the voltage of all the nodes meets the voltage constraint, determining that load shedding is not carried out, if the voltage of the nodes is lower than the lower limit, starting from the tail end of the fault area, cutting off the load according to the importance level sequence of the load, and calculating the voltage amplitude of out-of-limit node until the voltage of the fault area meets the constraint; and determining a final cut load scheme according to the third cut load scheme and the non-fault zone voltage constraint.
2. The method for calculating the cut load under the fault of the transformer N-1 according to claim 1, wherein the networking parameters comprise a topology structure, an importance level of the load, a line parameter and a load parameter of the flexible interconnection power distribution network.
3. The method for calculating the cut load under the fault of the transformer N-1 according to claim 1, wherein the first cut load scheme is determined according to the capacity constraint of the flexible interconnection device based on the networking parameters, further comprising the steps of:
when the first load capacity is negative, calculating from the outlet of the fault side transformer, and determining the distributed power supply needing to be cut off.
4. The method for load shedding calculation under a fault of a transformer N-1 according to claim 1, wherein the second load shedding scheme is determined according to the first load shedding scheme and the transformer capacity constraint, further comprising the steps of:
when the second cut load capacity is a negative value, starting calculation from the outlet of the fault side transformer, and determining the distributed power supply needing to be cut off.
5. The method for load shedding calculation under a fault of a transformer N-1 according to claim 1, wherein the third load shedding scheme is determined according to the second load shedding scheme and the fault zone node voltage constraint, further comprising the steps of:
when the sum of all loads of the fault area is negative, setting the alternating-current side voltage of the flexible interconnection device as the lower limit value of voltage permission, carrying out load flow calculation on the fault area to obtain the voltage of load nodes of the fault area, if the voltage of all nodes meets the voltage constraint, determining that the distributed power supply is not required to be cut off, if the node voltage is lower than the lower limit, cutting off the distributed power supply of the tail end node of the fault area, and calculating the voltage amplitude of the out-of-limit node until the voltage of the fault area meets the constraint.
6. The method for load shedding calculation under a fault of a transformer N-1 according to claim 1, wherein the final load shedding scheme is determined according to a third load shedding scheme and a non-fault zone voltage constraint, comprising the steps of:
according to a third load shedding scheme of the fault area, the sum of all loads of the fault area is equivalent to the equivalent load of an access node of the alternating current side of the flexible interconnection device, and according to the equivalent load of the access node of the flexible interconnection device, the sum of all loads of the non-fault area is calculated;
and when the sum of all loads of the non-fault area is positive, carrying out load flow calculation on the non-fault area to obtain node voltages, if the voltages of all the nodes meet the voltage constraint, determining that load shedding is not carried out, and if the node voltages are lower than the lower limit, starting from the tail end of the fault area, cutting off the loads according to the importance level sequence of the loads, and calculating the voltage amplitude of the out-of-limit node until the voltage of the non-fault area meets the constraint.
7. The method for load shedding calculation under a fault of a transformer N-1 according to claim 6, wherein the final load shedding scheme is determined according to a third load shedding scheme and a non-fault zone voltage constraint, further comprising the steps of:
and when the sum of all loads of the non-fault area is negative, carrying out load flow calculation on the non-fault area to obtain node voltages, if the voltages of all the nodes meet the voltage constraint, determining that the distributed power supply does not need to be cut off, if the node voltages are lower than the lower limit, cutting off the distributed power supply of the node at the tail end of the fault area, and calculating the out-of-limit node voltage amplitude until the voltage of the non-fault area meets the constraint.
8. The load shedding calculation method under a fault of a transformer N-1 according to claim 6 or 7, wherein load shedding is performed in order of importance level of the load, and the threshold crossing node voltage amplitude is calculated, comprising the steps of:
and after the load is cut off in the fault area, determining the voltage of the out-of-limit node according to the voltage of the node before the load of the end node is not cut off, the voltage of the end node of the line, the resistance of the line, the reactance of the line, the active power of the end node of the fault area is cut off, and the reactive power of the end node of the fault area is cut off.
9. The method for calculating the cut load under the fault of the transformer N-1 according to claim 7, wherein the distributed power supply of the terminal node of the fault block is cut off, and the voltage amplitude of the out-of-limit node is calculated, comprising the steps of:
and after the distributed power supplies of the end nodes of the fault area are cut off, determining the voltage of the out-of-limit node according to the voltage of the node before the load of the end node is not cut off, the voltage of the end node of the line, the resistance of the line, the reactance of the line, the active power of the distributed power supplies of the end nodes of the fault area are cut off, and the reactive power of the distributed power supplies of the end nodes of the fault area.
10. A load shedding computing system under a transformer N-1 fault, comprising:
the data acquisition module is used for acquiring networking parameters of the flexible interconnection power distribution network;
the data calculation module is used for determining a load shedding scheme according to capacity constraint of the flexible interconnection device, capacity constraint of the transformer, node voltage constraint of the fault area and voltage constraint of the non-fault area based on networking parameters, and comprises the following steps: based on networking parameters, determining a first load shedding scheme according to flexible interconnection device capacity constraints comprises: determining a first all-load capacity of a fault area according to SOP capacity constraint based on networking parameters; when the first cut load capacity is a positive value, starting calculation from the outlet of the fault side transformer, cutting off the load according to the importance level sequence of the load until the cut load capacity reaches the first cut load capacity; determining a second cut-load scheme from the first cut-load scheme and the transformer capacity constraint includes: determining a second load shedding capacity of the fault transformer area according to the capacity of the non-fault transformer and the capacity of the SOP based on the first load shedding scheme; when the second cut load capacity is a positive value, starting calculation from the outlet of the fault side transformer, cutting off the load according to the importance level sequence of the load until the cut load capacity reaches the second cut load capacity; determining a third load shedding scheme according to the second load shedding scheme and the fault zone node voltage constraint comprises: determining the sum of all loads of the fault area according to the second load shedding scheme; when the sum of all loads of the fault area is positive, setting the alternating-current side voltage of the flexible interconnection device as the upper limit value of voltage permission, carrying out load flow calculation on the fault area to obtain the voltage of load nodes of the fault area, if the voltage of all the nodes meets the voltage constraint, determining that load shedding is not carried out, if the voltage of the nodes is lower than the lower limit, starting from the tail end of the fault area, cutting off the load according to the importance level sequence of the load, and calculating the voltage amplitude of out-of-limit node until the voltage of the fault area meets the constraint; and determining a final cut load scheme according to the third cut load scheme and the non-fault zone voltage constraint.
11. A computer readable storage medium having stored thereon a computer program, which when executed by a processor implements the load shedding calculation method under a fault of the transformer N-1 as claimed in any one of claims 1 to 9.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114142515A (en) * | 2021-12-31 | 2022-03-04 | 江苏省电力试验研究院有限公司 | Distribution network flexible interconnection coordination control method and device |
| CN114462648A (en) * | 2022-03-29 | 2022-05-10 | 华北电力大学 | Power distribution network fault reconstruction based on SNOP |
| CN114530862A (en) * | 2022-01-24 | 2022-05-24 | 贵州创星电力科学研究院有限责任公司 | Load reducing method for flexible interconnected transformer substation |
| CN114665479A (en) * | 2022-05-24 | 2022-06-24 | 武汉大学 | Power distribution network power supply recovery method and system considering network reconfiguration |
| WO2022148258A1 (en) * | 2021-01-05 | 2022-07-14 | 国网上海能源互联网研究院有限公司 | Operation control method and system for court flexible interconnection system |
| CN115395557A (en) * | 2022-08-09 | 2022-11-25 | 武汉大学 | Active power distribution network fault rapid recovery method based on directed graph traversal |
| WO2022257712A1 (en) * | 2021-06-11 | 2022-12-15 | 国网上海市电力公司 | Method and system for controlling power distribution network distributed power supply energy storage for resilience improvement |
-
2023
- 2023-06-07 CN CN202310668316.7A patent/CN116388206B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022148258A1 (en) * | 2021-01-05 | 2022-07-14 | 国网上海能源互联网研究院有限公司 | Operation control method and system for court flexible interconnection system |
| WO2022257712A1 (en) * | 2021-06-11 | 2022-12-15 | 国网上海市电力公司 | Method and system for controlling power distribution network distributed power supply energy storage for resilience improvement |
| CN114142515A (en) * | 2021-12-31 | 2022-03-04 | 江苏省电力试验研究院有限公司 | Distribution network flexible interconnection coordination control method and device |
| CN114530862A (en) * | 2022-01-24 | 2022-05-24 | 贵州创星电力科学研究院有限责任公司 | Load reducing method for flexible interconnected transformer substation |
| CN114462648A (en) * | 2022-03-29 | 2022-05-10 | 华北电力大学 | Power distribution network fault reconstruction based on SNOP |
| CN114665479A (en) * | 2022-05-24 | 2022-06-24 | 武汉大学 | Power distribution network power supply recovery method and system considering network reconfiguration |
| CN115395557A (en) * | 2022-08-09 | 2022-11-25 | 武汉大学 | Active power distribution network fault rapid recovery method based on directed graph traversal |
Non-Patent Citations (1)
| Title |
|---|
| 柔性互联配电系统连锁故障风险评估;薛俞 等;《电力系统自动化》;第第45卷卷(第第8期期);112-119页 * |
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