CN115411729A - Voltage stability judging method and device for power system - Google Patents
Voltage stability judging method and device for power system Download PDFInfo
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- 238000000034 method Methods 0.000 title claims abstract description 28
- 230000009471 action Effects 0.000 claims abstract description 13
- 238000012216 screening Methods 0.000 claims description 7
- 238000010586 diagram Methods 0.000 description 5
- 244000144730 Amygdalus persica Species 0.000 description 3
- 235000006040 Prunus persica var persica Nutrition 0.000 description 3
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 239000010117 shenhua Substances 0.000 description 3
- 239000002023 wood Substances 0.000 description 3
- 241000334161 Cercis chinensis Species 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000002459 sustained effect Effects 0.000 description 2
- 241000220487 Bauhinia Species 0.000 description 1
- 235000008331 Pinus X rigitaeda Nutrition 0.000 description 1
- 235000011613 Pinus brutia Nutrition 0.000 description 1
- 241000018646 Pinus brutia Species 0.000 description 1
- 235000018907 Tylosema fassoglense Nutrition 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
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- 238000004088 simulation Methods 0.000 description 1
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- 230000001052 transient effect Effects 0.000 description 1
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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
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H1/00—Details of emergency protective circuit arrangements
- H02H1/0007—Details of emergency protective circuit arrangements concerning the detecting means
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H1/00—Details of emergency protective circuit arrangements
- H02H1/0061—Details of emergency protective circuit arrangements concerning transmission of signals
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
- H02H7/28—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured for meshed systems
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Abstract
The invention discloses a voltage stability judging method and a voltage stability judging device of a power system, wherein the method comprises the following steps: when a main protection action rejection fault occurs in any voltage node, positioning the fault voltage node and selecting an initial low-voltage node from a plurality of voltage nodes; performing homonymous combination on the plurality of initial low-voltage nodes, and selecting the initial low-voltage nodes meeting the preset continuous low-voltage condition as target low-voltage nodes; traversing the node topology by taking the fault voltage node as a starting point, and determining the node distance between each target low-voltage node and the fault voltage node; and searching the node topology by adopting the low-voltage node of the target to which the maximum node distance belongs, and determining the voltage state of the power system based on the search result, thereby accurately judging whether the voltage state of the power system is actually stable.
Description
Technical Field
The invention relates to the technical field of voltage stability judgment, in particular to a method and a device for judging voltage stability of an electric power system.
Background
In recent years, the problem of voltage stabilization in power systems is receiving increasing attention. In a receiving end area, the transient voltage stability problem of the power system caused by insufficient local reactive power is particularly prominent, and if the voltage stability of the receiving end area cannot be reliably evaluated and control measures cannot be taken in time, voltage breakdown and power failure accidents in a large range are likely to be caused.
In a conventional power system, it is generally necessary to ensure that the voltage of each bus is stable after a fault occurs, and specifically, the voltage stability determination is performed in a manner that the voltage level cannot be lower than a certain set value within a period of time, for example, a typical setting scheme sets the set value to 0.75p.u. and sets the time to 1s.
In the prior art, main protection refusal is also an important fault, and is different from common single-line and double-line tripping faults and the like in that the main protection refusal can jump out all outgoing lines after the fault, so that at least one bus (namely a main protection refusal point) is necessary to be an isolated node after the fault, and voltage instability exists. However, the judgment does not consider the factor that the voltage stability is not affected by the instability of the node which is separated from the system after the fault occurs, and whether the power system is actually in the voltage stable state cannot be accurately judged.
Disclosure of Invention
The invention provides a method and a device for judging voltage stability of a power system, which solve the technical problem that in the prior art, voltage instability judgment of faults such as main protection failure does not consider the factor that node instability separated from the system after the fault does not influence voltage stability, and whether the power system is actually in a voltage stable state or not can not be accurately judged.
The invention provides a voltage stability judging method of an electric power system, wherein the electric power system comprises a plurality of voltage nodes, the voltage nodes form a node topology, and the method comprises the following steps:
when a main protection action rejection fault of any one voltage node is detected, positioning the fault voltage node and selecting an initial low-voltage node from the voltage nodes;
performing homonymous combination on the plurality of initial low-voltage nodes, and selecting the initial low-voltage nodes meeting a preset continuous low-voltage condition as target low-voltage nodes;
traversing the node topology with the fault voltage node as a starting point, and determining a node distance between each target low-voltage node and the fault voltage node;
and searching the node topology by adopting the maximum low-voltage node of the node distance belonging target, and determining the voltage state of the power system based on the search result.
Optionally, the step of locating a failed voltage node and selecting an initial low voltage node from the plurality of voltage nodes when detecting that a main protection rejection fault occurs in any one of the voltage nodes includes:
when detecting that any one voltage node has a main protection refusing fault, positioning the voltage node with the main protection refusing fault as a fault voltage node;
and selecting a voltage node with the current voltage smaller than a preset voltage per unit value to determine as an initial low-voltage node.
Optionally, the initial low-voltage node is provided with a node name; the step of performing homonymous combination on the plurality of initial low-voltage nodes and selecting the initial low-voltage node satisfying a preset continuous low-voltage condition as a target low-voltage node includes:
carrying out homonymy combination on the initial low-voltage nodes according to the node names to obtain a plurality of intermediate low-voltage nodes;
and selecting the middle low-voltage node with the voltage grade larger than the preset grade threshold value and the low-voltage duration time larger than or equal to the preset time threshold value as the target low-voltage node.
Optionally, the step of traversing the node topology with the faulty voltage node as a starting point to determine a node distance between each target low-voltage node and the faulty voltage node includes:
traversing the node topology by taking the fault voltage node as a starting point, determining a target low voltage node adjacent to the starting point and marking a node distance as a preset node distance;
judging whether a target low-voltage node which does not mark the node distance exists;
if yes, the target low-voltage node marked with the node distance is used as a new starting point;
increasing the preset node distance according to a preset distance value;
skipping to execute the step of traversing the node topology, determining a target low-voltage node adjacent to the starting point and marking the node distance as a preset node distance until no target low-voltage node which is not marked with the node distance exists.
Optionally, the step of searching the node topology by using the maximum node distance to the target low-voltage node, and determining the voltage state of the power system based on the search result includes:
traversing the node topology, and judging whether a line connected with the voltage node exists between the maximum node and the target low-voltage node;
if the voltage state of the power system is the voltage instability state, judging that the voltage state of the power system at the current moment is a voltage instability state;
if not, judging whether the maximum node distance at the current moment is a preset distance threshold value or not;
if not, deleting all target low-voltage nodes corresponding to the maximum node distance, and skipping to execute the step of judging whether the maximum node distance at the current moment is a preset distance threshold value;
and if so, determining that the voltage state of the power system at the current moment is a voltage stable state.
The invention provides a voltage stability judging device of an electric power system, wherein the electric power system comprises a plurality of voltage nodes, the voltage nodes form a node topology, and the device comprises:
the low-voltage node selection module is used for positioning a fault voltage node and selecting an initial low-voltage node from a plurality of voltage nodes when a main protection refusal fault is detected to occur on any one of the voltage nodes;
the node merging and screening module is used for performing homonymous merging on the plurality of initial low-voltage nodes and selecting the initial low-voltage nodes meeting the preset continuous low-voltage condition as target low-voltage nodes;
a node distance determining module, configured to traverse the node topology with the fault voltage node as a starting point, and determine a node distance between each target low-voltage node and the fault voltage node;
and the voltage state determining module is used for searching the node topology by adopting the maximum low-voltage node to which the node distance belongs, and determining the voltage state of the power system based on the searching result.
Optionally, the low-voltage node selection module is specifically configured to:
when detecting that any one voltage node has a main protection refusing fault, positioning the voltage node with the main protection refusing fault as a fault voltage node;
and selecting a voltage node with the current voltage smaller than the preset voltage per unit value to be determined as an initial low-voltage node.
Optionally, the initial low-voltage node is provided with a node name; the node merging and screening module is specifically configured to:
carrying out homonymous combination on the initial low-voltage nodes according to the node names to obtain a plurality of intermediate low-voltage nodes;
and selecting the middle low-voltage node with the voltage grade larger than the preset grade threshold value and the low-voltage duration time larger than or equal to the preset time threshold value as the target low-voltage node.
Optionally, the node distance determining module is specifically configured to:
traversing the node topology by taking the fault voltage node as a starting point, determining a target low-voltage node adjacent to the starting point and marking a node distance as a preset node distance;
judging whether a target low-voltage node which does not mark the node distance exists;
if yes, the target low-voltage node marked with the node distance is used as a new starting point;
increasing the preset node distance according to a preset distance value;
and skipping to execute the step of traversing the node topology, determining a target low-voltage node adjacent to the starting point and marking the node distance as a preset node distance until no target low-voltage node which is not marked with the node distance exists.
Optionally, the voltage status determining module is specifically configured to:
traversing the node topology, and judging whether a line connected with the voltage node exists between the maximum node and the target low-voltage node;
if the voltage state of the power system is the voltage instability state, judging that the voltage state of the power system at the current moment is a voltage instability state;
if not, judging whether the maximum node distance at the current moment is a preset distance threshold value or not;
if not, deleting all target low-voltage nodes corresponding to the maximum node distance, and skipping to execute the step of judging whether the maximum node distance at the current moment is a preset distance threshold value;
and if so, determining that the voltage state of the power system at the current moment is a voltage stable state.
According to the technical scheme, the invention has the following advantages:
when a main protection action rejection fault of any voltage node is detected, positioning the fault voltage node and selecting an initial low-voltage node from a plurality of voltage nodes; performing homonymous combination on the plurality of initial low-voltage nodes, and selecting the initial low-voltage nodes meeting the preset continuous low-voltage condition as target low-voltage nodes; traversing the node topology by taking the fault voltage node as a starting point, and determining the node distance between each target low-voltage node and the fault voltage node; and searching the node topology by adopting the low-voltage node of the target to which the maximum node distance belongs, and determining the voltage state of the power system based on the search result, thereby accurately judging whether the voltage state of the power system is actually stable.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.
Fig. 1 is a flowchart illustrating a method for determining voltage stability of an electrical power system according to an embodiment of the present invention;
fig. 2 is a flowchart illustrating a method for determining voltage stability of an electrical power system according to a second embodiment of the present invention;
fig. 3 is a schematic node topology diagram of an electrical power system according to an embodiment of the present invention;
fig. 4 is a schematic node topology diagram of an electrical power system according to another embodiment of the present invention;
fig. 5 is a block diagram of a voltage stability determination device of an electric power system according to a third embodiment of the present invention.
Detailed Description
The embodiment of the invention provides a method and a device for judging voltage stability of a power system, which are used for solving the technical problem that in the prior art, voltage instability judgment of faults such as main protection refusal does not consider the factor that the voltage stability is not influenced by the node instability of a separation system after the faults, and whether the power system is actually in a voltage stable state or not cannot be accurately judged.
In order to make the objects, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the embodiments described below are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 1, fig. 1 is a flowchart illustrating a method for determining voltage stability of an electrical power system according to an embodiment of the present invention.
The invention provides a voltage stability judging method of an electric power system, wherein the electric power system comprises a plurality of voltage nodes, the voltage nodes form a node topology, and the method comprises the following steps:
the main protection action rejection fault refers to a fault type that the fault can be removed in the shortest time within the whole protection range of the protected element, other non-fault parts in the system can be ensured to continue to operate for protection, and the breaker does not act after a tripping or closing signal is sent when the protection needs tripping.
In the embodiment of the application, when a main protection action rejection fault occurs in a voltage node in a power system, the voltage node with the main protection action rejection fault is positioned to serve as a fault voltage node, and an initial low-voltage node lower than a threshold value is selected from a plurality of voltage nodes according to the voltage amplitude of each voltage node at the current moment.
It should be noted that before the detection of the power system, the initial low-voltage node may be selected while the fault voltage node is determined by performing the simulation of the main protection rejection fault tripping all outgoing lines at a certain specified voltage node.
and according to the node name of each initial low-voltage node, performing homonymy combination on each initial low-voltage node on the node topology, and meanwhile, selecting the initial low-voltage node meeting the continuous low-voltage condition to determine as the target low-voltage node.
The sustained low voltage condition includes, but is not limited to, a limit of a voltage level and a limit of a sustained low voltage time.
after the fault voltage node is determined, traversing the node topology by taking the position of the fault voltage node in the node topology as a starting point, and determining the node distance between each target low-voltage node and the fault voltage node according to the node topology by taking the position of the fault voltage node as 0.
And 104, searching node topology by adopting the low-voltage node of the target to which the maximum node distance belongs, and determining the voltage state of the power system based on the search result.
After the distance of each node is determined, searching node topology from a target low-voltage node farthest from a fault voltage node, judging whether circuits connected to other voltage nodes exist in the target low-voltage node to which the largest node is located according to the node topology, if yes, judging that the voltage state of the power system is voltage instability, if not, further judging whether the largest node distance is a preset distance threshold, and if yes, judging that the power state of the power system is voltage stability.
In the embodiment of the application, when a main protection rejection fault occurs in any voltage node, the fault voltage node is positioned, and an initial low-voltage node is selected from a plurality of voltage nodes; performing homonymous combination on the plurality of initial low-voltage nodes, and selecting the initial low-voltage nodes meeting the preset continuous low-voltage condition as target low-voltage nodes; traversing the node topology by taking the fault voltage node as a starting point, and determining the node distance between each target low-voltage node and the fault voltage node; and searching the node topology by adopting the low-voltage node of the target to which the maximum node distance belongs, and determining the voltage state of the power system based on the search result, thereby accurately judging whether the voltage state of the power system is actually stable.
Referring to fig. 2, fig. 2 is a flowchart illustrating a voltage stability determination method for an electrical power system according to a second embodiment of the present invention.
The invention provides a voltage stability judging method of an electric power system, wherein the electric power system comprises a plurality of voltage nodes, the voltage nodes form a node topology, and the method comprises the following steps:
optionally, step 201 may comprise the sub-steps of:
when detecting that any voltage node has a main protection refusing fault, positioning the voltage node with the main protection refusing fault as a fault voltage node;
and selecting a voltage node with the current voltage smaller than a preset voltage per unit value to determine as an initial low-voltage node.
In the embodiment of the application, when a main protection action rejection fault occurs in any voltage node, the voltage node where the main protection action rejection fault occurs is located as a fault voltage node, and a voltage node of which the current voltage is smaller than a preset voltage threshold value, for example, a voltage per unit value, is selected from all the voltage nodes to be determined as an initial low voltage node.
Wherein the voltage per unit value may be set to 0.75p.u.
optionally, the initial low voltage node is provided with a node name, and step 202 may include the following sub-steps:
carrying out homonymy combination on the initial low-voltage nodes according to the node names to obtain a plurality of intermediate low-voltage nodes;
and selecting the middle low-voltage node with the voltage grade larger than the preset grade threshold value and the low-voltage duration time larger than or equal to the preset time threshold value as the target low-voltage node.
In this embodiment, each initial low-voltage node is provided with a node name, the initial low-voltage nodes are merged according to the same name of each node, the initial low-voltage nodes with the same node name are merged, meanwhile, a plurality of obtained intermediate low-voltage nodes are screened, and the intermediate low-voltage node with a voltage level greater than a preset level threshold and a low-voltage duration greater than or equal to a preset time threshold is selected as a target low-voltage node.
For example, removing nodes of 110kV class and below (due to the main concern about nodes of 220kV and above), and removing part of the low voltage time insufficient nodes (i.e. less than 1 s), table 1 of the initial low voltage nodes can be as follows:
| numbering | Node name | Low voltage threshold | Starting time (second) | Duration (seconds) |
| 292 | Gui Hechi K1525 | 0.750 | 0.200 | 1.400 |
| 293 | Gui Hechi K2525 | 0.750 | 0.200 | 1.400 |
| 614 | Gui Hechi 505225 | 0.750 | 0.210 | 1.390 |
| 615 | Gui Hechi D1525 | 0.750 | 0.300 | 0.810 |
| 2002 | Gui Qingyuan 1115 | 0.750 | 0.380 | 0.780 |
| 616 | Gui Hechi D2525 | 0.750 | 0.300 | 0.750 |
| 2032 | Gui Duoji D1115 | 0.750 | 0.370 | 0.470 |
TABLE 1
As can be seen from the above table, after the initial low-voltage nodes are combined under the same name, the obtained intermediate low-voltage node is the bay river pond, the voltage levels of the qingyuan and multi-gigabit sites are low, the duration is insufficient, the obtained target low-voltage node is the bay river pond, the low-voltage threshold is 0.750, the duration is 1.400, and the starting time is 0.200.
optionally, step 203 may comprise the sub-steps of:
traversing the node topology by taking the fault voltage node as a starting point, determining a target low voltage node adjacent to the starting point and marking the node distance as a preset node distance;
judging whether a target low-voltage node with an unmarked node distance exists or not;
if so, taking the target low-voltage node with the marked node distance as a new starting point;
increasing the preset node distance according to the preset distance value;
and skipping to execute the step of traversing the node topology, determining a target low-voltage node adjacent to the starting point and marking the node distance as a preset node distance until no target low-voltage node with unmarked node distance exists.
In the embodiment of the application, the position of a fault voltage node in a node topology is taken as a starting point, the node topology is traversed, a target low-voltage node adjacent to the starting point is determined, the node distance of the target low-voltage node is marked as a preset node distance, whether a target low-voltage node not marked with the node distance exists is further judged, if the target low-voltage node exists, the target low-voltage node of each marked node distance is taken as a new starting point, the preset node distance is increased according to a preset distance value to serve as a new preset node distance, the remaining node topology is traversed again by using the new starting point, the target low-voltage node adjacent to the new starting point is determined, and the new preset node distance is marked until all the target low-voltage nodes are marked with the preset node distances.
step 205, if yes, determining that the voltage state of the power system at the current moment is a voltage instability state;
in step 208, if yes, it is determined that the voltage state of the power system at the current time is a voltage stable state.
Referring to fig. 3, fig. 3 shows a node topology according to an embodiment of the present application.
In the embodiment of the application, when the main protection action rejection fault occurs to the voltage node of the peach loosening station, the initial low-voltage node is selected and the operation is carried outMerging the same names, screening initial low-voltage nodes with the voltage grades larger than a preset grade threshold value and the low-voltage duration time larger than or equal to a preset time threshold value as target low-voltage nodes,as shown in table 2 below:
| number of | Node name | Low voltage threshold | Starting time (second) | Duration (seconds) |
| 8267 | Qian Song peach 51525. | 0.75 | 0.22 | 1.38 |
| 8374 | Qian Huayuan D1115. | 0.75 | 0.26 | 1.34 |
| 8351 | Qian Chang xing D1115. | 0.75 | 0.28 | 1.24 |
| 8382 | Qian Xiu mountain D1115. | 0.75 | 0.3 | 1.19 |
TABLE 2
In this embodiment, after merging, removing the low voltage level node and removing the node with insufficient low voltage time, the remaining nodes include: the method comprises the steps of calculating node distances between target low-voltage nodes and a pine peach station, determining that the nodes at 1 distance are the Huayuan and the Xiushan, and determining that the nodes at 2 distance are the giant trees. And judging whether the huge wood station is connected with other voltage nodes or not, if the huge wood station is not connected with the other voltage nodes, deleting the huge wood nodes, judging the Huayuan and the Xiushan, and judging that the voltage state of the power system at the current moment is the voltage stable state after determining that the two points are not connected with the system.
Referring to fig. 4, fig. 4 is a schematic node topology diagram of an electrical power system according to another embodiment of the present invention.
In this embodiment, after the single-phase main protection of the jiu long-run station is refused, the nodes with low voltage class and the nodes with low voltage and insufficient time are merged and removed, wherein the jiu long-run node is different from the jiu long-run node 22 and the fu Cheng Hefu in 22 voltage classes, which are respectively 500kV and 220kV classes, and are connected through a transformer instead of a line, the same point is calculated, and the remaining nodes include: qindi, jiugong, fucheng, zhucheng (Shenhua), duhai, zijing, pingyang, kongkou, faimean, sun Dong, and the corresponding node distances are calculated by the combined pulling as shown in Table 3 below:
| station | Distance between two adjacent plates |
| Jiulong (Jiulong) | 0 |
| Qinzhou two | 1 |
| Fu Cheng (good fortune) | 1 |
| Punching mouth | 1 |
| Pearl city (Shenhua) | 2 |
| Combined traction (i.e. combined traction) | 2 |
| Safety for |
2 |
| |
2 |
| |
2 |
| |
2 |
| Pier sea | 3 |
TABLE 3
The pier sea node with the distance of 3 is only connected with the Pingyang and the bauhinia, and is arranged in the original low-voltage node, so that the layer is deleted. In the layer with the distance of 2, the Zhucheng (Shenhua) is connected with the Meilin, the Cercis chinensis is connected with the Tieshan, and the washout is connected with Yan Ling, and the points are not arranged in the original low-voltage nodes, so that the power system is in a voltage instability state after the single-phase main protection of the Jiulong station refuses to operate.
In the embodiment of the application, when a main protection action rejection fault occurs to any voltage node, the fault voltage node is positioned, and an initial low-voltage node is selected from a plurality of voltage nodes; performing homonymous combination on the plurality of initial low-voltage nodes, and selecting the initial low-voltage nodes meeting the preset continuous low-voltage condition as target low-voltage nodes; traversing the node topology by taking the fault voltage node as a starting point, and determining the node distance between each target low-voltage node and the fault voltage node; and searching the node topology by adopting the low-voltage node of the target to which the maximum node distance belongs, and determining the voltage state of the power system based on the search result, thereby accurately judging whether the voltage state of the power system is actually stable.
Referring to fig. 5, fig. 5 is a block diagram of a voltage stability determination device of an electrical power system according to a third embodiment of the present invention.
The embodiment of the invention provides a voltage stability judging device of an electric power system, wherein the electric power system comprises a plurality of voltage nodes, the voltage nodes form a node topology, and the device comprises:
a low-voltage node selection module 401, configured to, when detecting that a main protection denial fault occurs at any one voltage node, locate a fault voltage node and select an initial low-voltage node from multiple voltage nodes;
a node merging and screening module 402, configured to perform homonymous merging on multiple initial low-voltage nodes, and select an initial low-voltage node that meets a preset continuous low-voltage condition as a target low-voltage node;
a node distance determining module 403, configured to traverse the node topology with the fault voltage node as a starting point, and determine a node distance between each target low-voltage node and the fault voltage node;
and a voltage state determining module 404, configured to search the node topology by using the low-voltage node to which the maximum node distance belongs, and determine the voltage state of the power system based on the search result.
Optionally, the low-voltage node selection module 401 is specifically configured to:
when detecting that any voltage node has a main protection refusing fault, positioning the voltage node with the main protection refusing fault as a fault voltage node;
and selecting a voltage node with the current voltage smaller than the preset voltage per unit value to be determined as an initial low-voltage node.
Optionally, the initial low-voltage node is provided with a node name; the node merging and screening module 402 is specifically configured to:
carrying out homonymy combination on the initial low-voltage nodes according to the node names to obtain a plurality of intermediate low-voltage nodes;
and selecting the middle low-voltage node with the voltage grade larger than the preset grade threshold value and the low-voltage duration time larger than or equal to the preset time threshold value as the target low-voltage node.
Optionally, the node distance determining module 403 is specifically configured to:
traversing the node topology by taking the fault voltage node as a starting point, determining a target low voltage node adjacent to the starting point and marking the node distance as a preset node distance;
judging whether a target low-voltage node with an unmarked node distance exists or not;
if so, taking the target low-voltage node with the marked node distance as a new starting point;
increasing the preset node distance according to the preset distance value;
and skipping to execute the step of traversing the node topology, determining a target low-voltage node adjacent to the starting point and marking the node distance as a preset node distance until no target low-voltage node with unmarked node distance exists.
Optionally, the voltage state determining module 404 is specifically configured to:
traversing the node topology, and judging whether a line connected with a voltage node exists in the target low-voltage node with the maximum node distance;
if the voltage state of the power system is the voltage instability state, judging that the voltage state of the power system at the current moment is a voltage instability state;
if not, judging whether the maximum node distance at the current moment is a preset distance threshold value or not;
if not, deleting all target low-voltage nodes corresponding to the maximum node distance, and skipping to execute the step of judging whether the maximum node distance at the current moment is a preset distance threshold value;
if yes, the voltage state of the power system at the current moment is judged to be a voltage stable state.
It can be clearly understood by those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described apparatuses and modules may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.
In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention 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 solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. A method for judging voltage stability of an electric power system, wherein the electric power system comprises a plurality of voltage nodes, and the plurality of voltage nodes form a node topology, the method comprising:
when a main protection action rejection fault occurs to any one voltage node, positioning the fault voltage node and selecting an initial low-voltage node from the voltage nodes;
performing homonymous combination on the plurality of initial low-voltage nodes, and selecting the initial low-voltage nodes meeting a preset continuous low-voltage condition as target low-voltage nodes;
traversing the node topology with the fault voltage node as a starting point, and determining a node distance between each target low-voltage node and the fault voltage node;
and searching the node topology by adopting the maximum low-voltage node of the node distance belonging target, and determining the voltage state of the power system based on the search result.
2. The method of claim 1, wherein said step of locating a failed voltage node and selecting an initial low voltage node from a plurality of said voltage nodes upon detecting a primary protection rejection fault at any one of said voltage nodes comprises:
when detecting that any one voltage node has a main protection refusing fault, positioning the voltage node with the main protection refusing fault as a fault voltage node;
and selecting a voltage node with the current voltage smaller than a preset voltage per unit value to determine as an initial low-voltage node.
3. The method of claim 1, wherein the initial low voltage node is provided with a node name; the step of performing homonymous combination on the plurality of initial low-voltage nodes and selecting the initial low-voltage node satisfying a preset continuous low-voltage condition as a target low-voltage node includes:
carrying out homonymy combination on the initial low-voltage nodes according to the node names to obtain a plurality of intermediate low-voltage nodes;
and selecting the middle low-voltage node with the voltage grade larger than the preset grade threshold value and the low-voltage duration larger than or equal to the preset time threshold value as the target low-voltage node.
4. The method of claim 1, wherein said step of traversing said node topology starting from said failed voltage node to determine a node distance between each of said target low voltage nodes and said failed voltage node comprises:
traversing the node topology by taking the fault voltage node as a starting point, determining a target low-voltage node adjacent to the starting point and marking a node distance as a preset node distance;
judging whether a target low-voltage node which does not mark the node distance exists;
if so, taking the target low-voltage node marked with the node distance as a new starting point;
increasing the preset node distance according to a preset distance value;
and skipping to execute the step of traversing the node topology, determining a target low-voltage node adjacent to the starting point and marking the node distance as a preset node distance until no target low-voltage node which is not marked with the node distance exists.
5. The method of claim 1, wherein the step of searching the node topology using the maximum node distance to the target low voltage node, and determining the voltage state of the power system based on the searching result comprises:
traversing the node topology, and judging whether a line connected with the voltage node exists between the maximum node and the target low-voltage node;
if the voltage state of the power system is the voltage instability state, judging that the voltage state of the power system at the current moment is a voltage instability state;
if not, judging whether the maximum node distance at the current moment is a preset distance threshold value or not;
if not, deleting all target low-voltage nodes corresponding to the maximum node distance, and skipping to execute the step of judging whether the maximum node distance at the current moment is a preset distance threshold value;
and if so, determining that the voltage state of the power system at the current moment is a voltage stable state.
6. A voltage stability determination apparatus for an electric power system, wherein the electric power system includes a plurality of voltage nodes, and a node topology is formed by the plurality of voltage nodes, the apparatus comprising:
the low-voltage node selection module is used for positioning a fault voltage node and selecting an initial low-voltage node from a plurality of voltage nodes when a main protection action rejection fault of any one voltage node is detected;
the node merging and screening module is used for performing homonymous merging on the plurality of initial low-voltage nodes and selecting the initial low-voltage nodes meeting the preset continuous low-voltage condition as target low-voltage nodes;
a node distance determining module, configured to traverse the node topology with the fault voltage node as a starting point, and determine a node distance between each target low-voltage node and the fault voltage node;
and the voltage state determining module is used for searching the node topology by adopting the maximum low-voltage node to which the node distance belongs, and determining the voltage state of the power system based on the searching result.
7. The apparatus of claim 6, wherein the low voltage node selection module is specifically configured to:
when detecting that any one voltage node has a main protection refusing fault, positioning the voltage node with the main protection refusing fault as a fault voltage node;
and selecting a voltage node with the current voltage smaller than a preset voltage per unit value to determine as an initial low-voltage node.
8. The apparatus of claim 6, wherein the initial low voltage node is provided with a node name; the node merging and screening module is specifically configured to:
carrying out homonymy combination on the initial low-voltage nodes according to the node names to obtain a plurality of intermediate low-voltage nodes;
and selecting the middle low-voltage node with the voltage grade larger than the preset grade threshold value and the low-voltage duration time larger than or equal to the preset time threshold value as the target low-voltage node.
9. The apparatus of claim 6, wherein the node distance determining module is specifically configured to:
traversing the node topology by taking the fault voltage node as a starting point, determining a target low-voltage node adjacent to the starting point and marking a node distance as a preset node distance;
judging whether a target low-voltage node which does not mark the node distance exists;
if yes, the target low-voltage node marked with the node distance is used as a new starting point;
increasing the preset node distance according to a preset distance value;
and skipping to execute the step of traversing the node topology, determining a target low-voltage node adjacent to the starting point and marking the node distance as a preset node distance until no target low-voltage node which is not marked with the node distance exists.
10. The apparatus of claim 6, wherein the voltage status determination module is specifically configured to:
traversing the node topology, and judging whether a line connected with the voltage node exists between the maximum node and the target low-voltage node;
if the voltage state of the power system is the voltage instability state, judging that the voltage state of the power system at the current moment is a voltage instability state;
if not, judging whether the maximum node distance at the current moment is a preset distance threshold value or not;
if not, deleting all target low-voltage nodes corresponding to the maximum node distance, and skipping to execute the step of judging whether the maximum node distance at the current moment is a preset distance threshold value;
and if so, determining that the voltage state of the power system at the current moment is a voltage stable state.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008187825A (en) * | 2007-01-30 | 2008-08-14 | Mitsubishi Electric Corp | Distance relaying apparatus |
| CN103532520A (en) * | 2013-11-03 | 2014-01-22 | 南京南瑞集团公司 | Reactive power compensation device control method for preventing large-scale chain offline of wind generation sets |
| CN104993466A (en) * | 2015-06-30 | 2015-10-21 | 南方电网科学研究院有限责任公司 | Cascading fault fast dynamic simulation method applicable to alternating current-direct current power grid |
| CN109188138A (en) * | 2018-09-11 | 2019-01-11 | 广东电网有限责任公司 | A kind of voltage dip frequency appraisal procedure and device |
| CN109256774A (en) * | 2018-10-18 | 2019-01-22 | 全球能源互联网研究院有限公司 | A kind of power grid subgraph partitioning method and device based on voltage class |
| CN109872112A (en) * | 2017-12-05 | 2019-06-11 | 国家电网公司 | A kind of full-automatic closed loop detection method and device of intelligent substation |
| CN112491057A (en) * | 2020-10-10 | 2021-03-12 | 东北电力大学 | Distributed energy storage control method with aim of eliminating node voltage out-of-limit of power distribution network |
| CN114611278A (en) * | 2022-03-03 | 2022-06-10 | 四川大学 | Multi-stage voltage sag state estimation method |
-
2022
- 2022-09-30 CN CN202211213218.6A patent/CN115411729B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008187825A (en) * | 2007-01-30 | 2008-08-14 | Mitsubishi Electric Corp | Distance relaying apparatus |
| CN103532520A (en) * | 2013-11-03 | 2014-01-22 | 南京南瑞集团公司 | Reactive power compensation device control method for preventing large-scale chain offline of wind generation sets |
| CN104993466A (en) * | 2015-06-30 | 2015-10-21 | 南方电网科学研究院有限责任公司 | Cascading fault fast dynamic simulation method applicable to alternating current-direct current power grid |
| CN109872112A (en) * | 2017-12-05 | 2019-06-11 | 国家电网公司 | A kind of full-automatic closed loop detection method and device of intelligent substation |
| CN109188138A (en) * | 2018-09-11 | 2019-01-11 | 广东电网有限责任公司 | A kind of voltage dip frequency appraisal procedure and device |
| CN109256774A (en) * | 2018-10-18 | 2019-01-22 | 全球能源互联网研究院有限公司 | A kind of power grid subgraph partitioning method and device based on voltage class |
| CN112491057A (en) * | 2020-10-10 | 2021-03-12 | 东北电力大学 | Distributed energy storage control method with aim of eliminating node voltage out-of-limit of power distribution network |
| CN114611278A (en) * | 2022-03-03 | 2022-06-10 | 四川大学 | Multi-stage voltage sag state estimation method |
Non-Patent Citations (3)
| Title |
|---|
| RIFAT ARA 等: "A Reliable Protection Scheme for Fast DC Fault Clearance in a VSC-Based Meshed MTDC Grid", 《IEEE ACCESS》, 21 May 2020 (2020-05-21), pages 88188 - 88199, XP011789385, DOI: 10.1109/ACCESS.2020.2993001 * |
| 杨文辉 等: "关键后备保护过负荷闭锁方案研究", 《华北电力大学学报》, vol. 38, no. 3, 31 May 2011 (2011-05-31), pages 1 - 6 * |
| 郑浩野: "基于时序网络结合深度学习的变电站继电保护故障诊断方法", 《电子器件》, vol. 45, no. 2, 30 April 2022 (2022-04-30), pages 396 - 402 * |
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