Regional power grid main and distribution cooperative operation optimization method and system

Abstract

The invention discloses a regional power grid main and distribution cooperative operation optimization method and system, and the method comprises the steps: building a topological connection diagram of a regional power grid based on a connection line of a main network and a distribution network in the regional power grid, and the topological characteristics of wiring in a distribution network transformer substation; determining the working state of each edge in the topological connection diagram before optimization; wherein the working state comprises a running state or a non-running state; the weight of an edge in a non-operation state in the distribution network is set as a micro power value; taking minimization of working state change times of all edges in the topological connection diagram as an objective function, and establishing an operation optimization model of the regional power grid; and solving the operation optimization model to obtain a working state set of all edges in the distribution network, and taking the working state set as a target operation mode of the distribution network. According to the method, a more reasonable and more practical power grid operation mode can be obtained, so that the efficiency and reliability of power grid regulation and control are improved, and the application requirements of a regional power grid are better met.

Description

Technical Field

[0001] The present invention relates to the technical field of power grids, and in particular to a method and system for optimizing coordinated operation of a regional power grid main distribution system. Background Art

[0002] In the current power system, grid dispatching plays a vital role, and its main function is to ensure the efficient transmission and reasonable distribution of electric energy. In the regional power grid, the scope of dispatching usually extends from the 220kV main grid to the 10kV feeder outgoing line, covering power networks of multiple voltage levels.

[0003] In the existing regional power grid control system, although the power flow analysis software for dispatchers has been developed, its operation depends on a large amount of high-precision data. However, due to the long-term lack of maintenance, especially the large errors in the parameters of components such as lines, the accuracy and reliability of the power flow calculation results are affected. Therefore, the power flow analysis software has not been effectively used by dispatchers and operation mode planners, and its practicality is insufficient. This is also a common challenge faced by many advanced application software in the current control system.

[0004] Given that the current regional power grid operation mode and maintenance plan formulation generally lack effective automated analysis tools, resulting in extremely heavy manual workload, there is an urgent need to develop a practical operation mode optimization method to improve the efficiency of power grid regulation. Summary of the invention

[0005] The purpose of the embodiments of the present invention is to provide a method and system for optimizing the coordinated operation of the main and distribution networks of a regional power grid. A topological connection diagram of the regional power grid is constructed through the connection lines of the main grid and the distribution network, and the topological characteristics of the wiring in the distribution network substation. The optimization goal is to minimize the adjustment of the power grid operation mode. A more reasonable and practical power grid operation mode can be obtained, thereby improving the efficiency and reliability of power grid regulation and better meeting the application needs of the regional power grid.

[0006] The first embodiment of the present invention provides a method for optimizing coordinated operation of a regional power grid main distribution, including:

[0007] Based on the connection lines between the main network and the distribution network in the regional power grid, and the topological characteristics of the wiring in the distribution network substation, a topological connection diagram of the regional power grid is constructed;

[0008] Determine the working state of each edge in the topology connection diagram before optimization; wherein the working state includes: an operating state or a non-operating state; the weight of the edge in the distribution network in the non-operating state is set to a small power value;

[0009] Taking minimizing the number of working state changes of all edges in the topological connection graph as the objective function, an operation optimization model of the regional power grid is established;

[0010] The operation optimization model is solved to obtain a collection of working states of all edges in the distribution network, and the collection of working states is used as a target operation mode of the distribution network.

[0011] Optionally, the topological characteristics of the wiring in the distribution network substation include:

[0012] In the distribution network substation, each section of the bus is regarded as a node, and the equipment connected to the bus is regarded as an edge; wherein the bus includes: a high-voltage side bus and a low-voltage side bus.

[0013] Optionally, the nodes in the topological connection diagram include: a main grid substation node, a high-voltage side node and a low-voltage side node of the distribution grid substation; wherein the high-voltage side node is a high-voltage side bus node of the distribution grid substation; and the low-voltage side node is a low-voltage side bus node of the distribution grid substation.

[0014] Optionally, the working states of each edge of the main network before and after the optimization are the same.

[0015] Optionally, the objective function is determined by the following formula:

[0016]

[0017] Among them, Z is the objective function; m is the edge number; Λo is the set of edges in the non-operating state before optimization; Λi is the set of edges in the operating state before optimization; xm is the working state of edge m, if it is in the operating state, xm=1, if it is in the non-operating state, xm=0.

[0018] Optionally, the operation optimization model is configured with a distribution network operation topology constraint set and a power grid operating characteristic constraint set; wherein, the distribution network operation topology constraint set is used to limit the number of edges in the distribution network in the operating state according to the operation topology rules of the distribution network; the power grid operating characteristic constraint set is used to limit the operating parameters of each edge in the operating state and the connection nodes to meet the operating parameter rules of the regional power grid.

[0019] Optionally, the distribution network operation topology constraint condition set includes: distribution network open-loop operation topology constraint conditions and distribution network substation connection topology constraint conditions.

[0020] Optionally, the distribution network substation wiring topology constraint conditions are as follows:

[0021]

[0022] Among them, m is the edge number; Λtm is the set of edges between the high-voltage side node and the low-voltage side node of the distribution network substation in the non-operating state; Λl is the set of edges in path l connecting the two high-voltage side busbars via the edge on the low-voltage side; Ll is the number of edges in path l; Γ is the set of path numbers connecting the two high-voltage side busbars via the edge on the low-voltage side; xm is the working state of edge m, if it is in the operating state, xm=1, if it is in the non-operating state, xm=0.

[0023] Optionally, the grid operating characteristic constraint condition set includes: node power flow balance constraint conditions, main grid substation overload constraint conditions, node maximum output limit constraint conditions, connection equipment limit constraint conditions and loop limit constraint conditions.

[0024] A second aspect of the present invention provides a regional power grid main distribution coordinated operation optimization system, including:

[0025] A topology diagram construction module, used to construct a topology connection diagram of the regional power grid based on the connection lines between the main grid and the distribution grid in the regional power grid, and the topological characteristics of the wiring in the distribution grid substation;

[0026] A state determination module, used to determine the working state of each edge in the topology connection diagram before optimization; wherein the working state includes: an operating state or a non-operating state; the weight of the edge in the distribution network in the non-operating state is set to a small power value;

[0027] An optimization model building module, used to establish an operation optimization model of the regional power grid by minimizing the number of working state changes of all edges in the topological connection diagram as an objective function;

[0028] The optimization model solving module is used to solve the operation optimization model, obtain the working state collection of all edges in the distribution network, and use the working state collection as the target operation mode of the distribution network.

[0029] Compared with the prior art, the embodiment of the present invention provides a method and system for optimizing the coordinated operation of the main and distribution networks of a regional power grid, the method comprising: constructing a topological connection diagram of the regional power grid based on the connection lines of the main network and the distribution network in the regional power grid, and the topological characteristics of the wiring in the distribution network substation; determining the working state of each edge in the topological connection diagram before optimization; wherein the working state includes: operating state or non-operating state; the weight of the edge in the non-operating state in the distribution network is set to a small power value; taking the minimization of the number of working state changes of all edges in the topological connection diagram as the objective function, establishing an operation optimization model of the regional power grid; solving the operation optimization model, obtaining the working state collection of all edges in the distribution network, and taking the working state collection as the target operation mode of the distribution network. The present invention constructs a topological connection diagram of the regional power grid through the connection lines of the main network and the distribution network, and the topological characteristics of the wiring in the distribution network substation, and takes the minimum adjustment of the power grid operation mode as the optimization goal, so as to obtain a more reasonable and practical power grid operation mode, thereby improving the efficiency and reliability of power grid regulation, and better meeting the application needs of the regional power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a flow chart of an embodiment of a method for optimizing coordinated operation of a regional power grid main distribution provided by the present invention;

[0031] Figure 2 It is a schematic diagram of an embodiment of wiring in a distribution network substation provided by the present invention;

[0032] Figure 3 It is a schematic diagram of an embodiment of a topological connection diagram of a regional power grid provided by the present invention;

[0033] Figure 4 It is a schematic diagram of another embodiment of the topological connection diagram of the regional power grid provided by the present invention;

[0034] Figure 5 It is a structural schematic diagram of an embodiment of a regional power grid main distribution coordinated operation optimization system provided by the present invention. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this technical field without creative work are within the scope of protection of the present invention.

[0036] See also Figure 1 , is a flow chart of an embodiment of the method for optimizing coordinated operation of the main and distribution systems of a regional power grid provided by the present invention.

[0037] The first aspect of the present invention provides a method for optimizing coordinated operation of a regional power grid main distribution, including steps S1 to S4, which are as follows:

[0038] Step S1: constructing a topological connection diagram of the regional power grid based on the connection lines between the main grid and the distribution grid in the regional power grid and the topological characteristics of the wiring in the distribution grid substation;

[0039] Step S2: determining the working state of each edge in the topology connection diagram before optimization; wherein the working state includes: an operating state or a non-operating state; the weight of the edge in the distribution network in the non-operating state is set to a small power value;

[0040] Step S3: Taking minimizing the number of working state changes of all edges in the topological connection graph as the objective function, establishing an operation optimization model of the regional power grid;

[0041] Step S4: Solve the operation optimization model to obtain a collection of working states of all edges in the distribution network, and use the collection of working states as a target operation mode of the distribution network.

[0042] It should be noted that a topological connection diagram of a regional power grid is constructed by analyzing the connection lines of the main grid and the distribution grid in the regional power grid (i.e., the main grid operates in a ring and the distribution grid operates in an open loop), as well as the topological characteristics of the wiring in the distribution grid substation. Compared with the prior art, the embodiment of the present invention also fully considers the wiring mode in the distribution grid substation and no longer simplifies it as a load node to ensure the rationality and comprehensiveness of the topological diagram, which helps to improve the practicality of the grid operation mode.

[0043] After having a complete topological connection diagram, determine the initial working state of each edge in the diagram. Further, solve the problem with the minimum adjustment of the grid operation mode as the optimization goal, and obtain the target operation mode of the distribution network. That is, the objective function is to minimize the number of working state changes of all edges in the topological connection diagram; this means to minimize the number of switching operations of the line / equipment as much as possible, thereby effectively reducing the operational risks of the operation and maintenance personnel, improving the efficiency of maintenance work, shortening the power outage time of the equipment, and taking into account the stability of the grid.

[0044] The embodiment of the present invention constructs a topological connection diagram of a regional power grid through the connection lines of the main grid and the distribution grid, and the topological characteristics of the wiring in the distribution grid substation, and establishes an operation optimization model of a regional power grid with coordinated main and distribution grids, with the optimization goal of minimizing the adjustment of the grid operation mode. Compared with the prior art, the present invention can obtain a more reasonable and practical grid operation mode, thereby improving the efficiency and reliability of grid regulation and better meeting the application needs of the regional power grid.

[0045] In an optional embodiment, the topological characteristics of the wiring in the distribution network substation include:

[0046] In the distribution network substation, each section of the bus is regarded as a node, and the equipment connected to the bus is regarded as an edge; wherein the bus includes: a high-voltage side bus and a low-voltage side bus.

[0047] It should be noted that in regional power grid dispatching, the dispatching scope usually includes the main transformer of the 220kV substation, and the 110kV and 35kV distribution networks. Its impact range involves the 220kV main network and distribution networks of various voltage levels. Therefore, when arranging the operation mode, it is necessary to consider the impact on the main network and the distribution network at the same time, and establish a topological connection diagram including the main network and the distribution network. At present, in order to improve the reliability of power supply, the main network is usually operated in a ring (i.e., the main network topological characteristics); in order to avoid the formation of an electromagnetic ring network, reduce short-circuit fault current, simplify the configuration of relay protection devices, and reduce costs, the distribution network needs to be operated in an open loop (i.e., the distribution network topological characteristics), so the topological connection between the main network and the distribution network is different.

[0048] In addition, when formulating the operation mode, the wiring mode inside the distribution network substation must also be fully considered to determine the topological characteristics of the wiring inside the distribution network substation. Taking the internal bridge wiring, which is the most commonly used in the current 110kV substation (distribution network substation), as an example, the wiring diagram of the distribution network substation is as follows: Figure 2 shown.

[0049] exist Figure 2 In the present invention, since the distribution network is in open-loop operation, the normal operation mode is that one high-voltage side incoming line carries one main transformer (or one high-voltage side incoming line carries two main transformers), and the other incoming line is in a non-operating state. Therefore, the distribution network substation cannot be simplified as a load node. In this embodiment of the present invention, the 10kV feeder is used as the load, the busbar is used as the node, and the equipment connected to the busbar (such as switchgear, circuit breakers and transformers, etc.) is used as the edge. Figure 2 A simplified description is given. Figure 2 The topological structure of the distribution substation shown contains 4 nodes and 7 edges; among them, node 1 and node 2 are high-voltage side busbars; node 3 and node 4 are low-voltage side busbars; edges 1, 3 and 4 are devices connecting the high-voltage side incoming line and the high-voltage side busbar; edges 5 and 7 are devices (main transformers) connecting the high-voltage side busbars and the low-voltage side busbars; edge 2 is a device connecting between high-voltage side busbars, and edge 6 is a device connecting between low-voltage side busbars.

[0050] like Figure 3 FIG. 1 is a schematic diagram of an embodiment of a topological connection diagram of a regional power grid provided by the present invention.

[0051] In an optional embodiment, the nodes in the topological connection diagram include: a main grid substation node, a high-voltage side node and a low-voltage side node of the distribution grid substation; wherein the high-voltage side node is a high-voltage side bus node of the distribution grid substation; and the low-voltage side node is a low-voltage side bus node of the distribution grid substation.

[0052] It is worth noting that the topological characteristics of the wiring inside the main grid substation include: when the main transformer and the busbar in the main grid substation are operated in parallel, the main grid substation is represented by a main grid substation node; when the main transformer and the busbar in the main grid substation are operated separately, each busbar is regarded as a busbar node, and all busbar nodes are used to represent the main grid substation. Specifically, in order to improve the reliability of power supply, the wiring inside the main grid substation usually makes the main transformer (main transformer) and the busbar run in parallel. At this time, the main grid substation can be represented by a node (such as Figure 3 ), if the main transformer and busbar are operated separately, the separated buses also need to be treated as nodes respectively.

[0053] like Figure 3 The topological connection diagram shown includes: the main grid partial network and the distribution grid partial network. The main grid partial network is a closed-loop operation. If the main grid substations belong to the same ultra-high voltage supply area, the interconnected main grid edges are in operation under normal circumstances. The distribution network partial network is an open-loop operation and meets the topological characteristics of the wiring in the distribution network substation; among them, the main grid partial network is a network formed by the interconnection of the main grid substations, and its main grid edges are the edges connecting the main grid substations.

[0054] In an optional embodiment, the working status of each edge of the main network is the same before and after the optimization.

[0055] It should be noted that the edges of the main network (main network edges) are only the edges connecting the main network substations, and do not include the edges connecting the main network substations and the distribution network substations (this edge is the distribution network edge). In other words, the main network is the backbone network that undertakes the main task of power transmission, and the distribution network is responsible for distributing power from the main network to smaller branch networks.

[0056] The working state adjustment of the main grid edge is confirmed by the operator himself, and the working state of the main grid edge before and after optimization is the same. For example, before optimization, the operator confirms that the working state of a main grid edge is changed from operating state to non-operating state, which remains unchanged from the working state of the main grid edge. This will be used as the working state collection before the main grid optimization. Then, when solving the optimization model, only the working state of the distribution grid edge is solved. Of course, the embodiment of the present invention takes the minimum adjustment of the grid operation mode as the optimization goal. Since "one move affects the whole body", the working state of the main grid edge will not be changed during the solution process.

[0057] In an optional embodiment, the objective function is determined by the following formula:

[0058]

[0059] Among them, Z is the objective function; m is the edge number; Λo is the set of edges in the non-operating state before optimization; Λi is the set of edges in the operating state before optimization; xm is the working state of edge m, if it is in the operating state, xm=1, if it is in the non-operating state, xm=0.

[0060] It should be noted that after having a complete topological connection diagram, the initial working state of each edge in the diagram is determined. Furthermore, the optimization goal is to minimize the adjustment of the grid operation mode and obtain the target operation mode of the distribution network. That is, the objective function is to minimize the number of working state changes of all edges in the topological connection diagram; this means to minimize the number of switching operations of the line / equipment as much as possible, thereby effectively reducing the operational risks of the operation and maintenance personnel, improving the efficiency of maintenance work, shortening the power outage time of the equipment, and taking into account the stability of the grid.

[0061] For example, suppose that some lines in the regional power grid need maintenance / standby (they are set to non-operating state before optimization / initial state), while other lines are in operation. During the optimization process (maintenance operation), the working state of other lines is modified as little as possible, that is, the edges of other lines that were originally in non-operating state are kept in non-operating state as much as possible, so that The edge that was originally in the running state is likely to be close to 0, and the edge that was originally in the running state is maintained as much as possible, so that It may be close to 0.

[0062] In an optional embodiment, the operation optimization model is configured with a distribution network operation topology constraint set and a power grid operating characteristic constraint set; wherein, the distribution network operation topology constraint set is used to limit the number of edges in the distribution network in the operating state according to the operation topology rules of the distribution network; the power grid operating characteristic constraint set is used to limit the operating parameters of each edge and connection node in the operating state to meet the operating parameter rules of the regional power grid.

[0063] It should be noted that in the topological connection diagram of the regional power grid, not all distribution network edges can be in operation at the same time. They need to comply with the operation topological rules of the distribution network to ensure that the distribution network can supply power normally. The grid operation characteristic constraint set is used to restrict the operation parameters of each edge in the topological connection diagram and the connected nodes to comply with the operation parameter rules of the regional power grid. The operation parameters are mainly power parameters.

[0064] In an optional embodiment, the distribution network operation topology constraint condition set includes: distribution network open-loop operation topology constraint conditions and distribution network substation connection topology constraint conditions.

[0065] It should be noted that the topological constraints for open-loop operation of the distribution network are:

[0066]

[0067] Where: M is the number of edges in the distribution network; xm is the working state of edge m, if it is in the operating state, xm=1, if it is in the non-operating state, xm=0; N is the total number of nodes, and Ns is the number of power supply nodes of the main grid substation (usually 220kV substation) connected to the distribution network. In other words, there are N-Ns edges in the distribution network that are in operation to ensure the open-loop operation of the distribution network.

[0068] Furthermore, the distribution network substation wiring topology constraints are as follows:

[0069]

[0070] Among them, m is the edge number; Λtm is the set of edges between the high-voltage side node and the low-voltage side node of the distribution network substation in the non-operating state; Λl is the set of edges in path l connecting the two high-voltage side busbars via the edge on the low-voltage side; Ll is the number of edges in path l; Γ is the set of path numbers connecting the two high-voltage side busbars via the edge on the low-voltage side; xm is the working state of edge m, if it is in the operating state, xm=1, if it is in the non-operating state, xm=0.

[0071] It should be noted that in addition to meeting the open-loop operation conditions, in order to improve the reliability of power supply, the edge between the high-voltage side node and the low-voltage side node of the distribution network substation should be in a non-operating state if it contains power outage maintenance equipment. If it does not contain power outage maintenance equipment, it should be in an operating state, and it is not a state of empty charging from the low-voltage side to the high-voltage side. That is, any two high-voltage side busbars in the distribution network substation are not electrically connected via the low-voltage side edge. The constraint is the distribution network substation wiring topology constraint. Figure 2 , the edge set Λl in path l is edge 5, edge 6 and edge 7; under normal circumstances, the two main transformers (main transformers) in the distribution substation should be in operation, and the main transformer is not in a state of empty charging from the low voltage side to the high voltage side, then edges 5 and 7 should be in operation, but it should be avoided that edge 6 is also in operation at the same time (that is, edge 6 is in a non-operating state).

[0072] In an optional embodiment, the grid operating characteristic constraint condition set includes: node flow balance constraint conditions, main grid substation overload constraint conditions, node maximum output limit constraint conditions, connection equipment limit constraint conditions and loop limit constraint conditions.

[0073] Specifically, the set of grid operating characteristic constraints (constraints on safe operation of components in the network) is as follows:

[0074] (1) Node power flow balance constraints:

[0075] ① The node power balance constraint condition for the main network (which already contains the connectivity of the main network) is:

[0076]

[0077] Among them, i and j are node numbers; fij is the power flowing from node i to node j, satisfying the relationship fij = -fji; Pi and Si are the load (i.e., the power consumed by the node) and the power supply (i.e., the power provided by the node) of node i respectively; Ψi is the set of adjacent node numbers of node i. Si-Pi represents the net power supply of node i.

[0078] The node power flow balance constraint equation of the above main network can be used to construct a topological model of the main network (ie, edge weight matrix) to achieve a description of the connectivity of the main network.

[0079] ② The node power flow balance constraint conditions for the distribution network are:

[0080]

[0081] Among them, εi is the injected power of the introduced micro-node, which is equivalent to the micro-power value set by the edge weight in the non-operating state in the distribution network.

[0082] Introducing tiny node injection power (or tiny power value) in the distribution network ensures that even if some nodes have zero load, they can still be connected to zero-load nodes in the topological model (edge ​​weight matrix) of the distribution network. In other words, zero load may mean no power inflow or outflow at the algorithm level, causing the algorithm to neglect the existence of the node during analysis; in this case, tiny power injection (or setting of tiny power value) can ensure that the zero-load node is considered as part of the distribution network, avoiding ignoring its potential adjustment effect.

[0083] like Figure 2 As shown, if the main transformer corresponding to edge 5 is in maintenance, the load of node 1 is 0, and it does not need to be connected to the rest of the distribution network to meet the flow constraint. In fact, at this time, one of edge 1 or edge 2 still needs to be in operation, so that the mother branch standby automatic switch or incoming line standby automatic switch can be put into operation to improve power supply reliability. Since there are standby or communication nodes with a load of 0 in the distribution network, it is impossible to directly use conventional flow constraint equations to describe their connectivity. For this reason, the embodiment of the present invention sets the edge weights of the non-operating state in the distribution network to a small power value. In other words, a small injection power is introduced into each node of the distribution network. While not affecting the accuracy requirements of the engineering application, it avoids the appearance of nodes with zero load in the network, so that the node flow balance constraint equation of the distribution network can clearly describe the connectivity of the distribution network.

[0084] (2) The main grid substation overload constraint conditions include the constraint that the main transformer of the main grid substation (usually a 220 kV substation) connected to the distribution network does not overload, as follows:

[0085]

[0086] Among them, Ψi,d is the set of node numbers of the adjacent distribution network nodes of node i; r is the load rate of the main transformer reaching heavy load; Ci is the capacity of the main transformer.

[0087] (3) Node maximum output limit constraint, that is, each node in the network must meet the maximum power output limit constraint:

[0088] Si≤Si,max;

[0089] Where Si,max is the maximum output of the power supply in node i.

[0090] (4) Connection equipment limit constraint condition, that is, the network flow must meet the constraint of not exceeding the connection equipment limit such as lines and transformers, as follows:

[0091] -xijrFij≤fij≤xijrFij;

[0092] Among them, Fij is the limit of connected devices between node i and node j; xij is the working status of the edge between node i and node j.

[0093] (5) Closing limit constraint conditions: For the tie switches with different 220kV supply areas on both sides, long-term closing to form an electromagnetic ring network should be avoided. For the tie switches with the same 220kV supply area on both sides, the closing current should be checked and calculated to avoid closing the side where the closing current exceeds the limit, as follows:

[0094] xm=0,m∈Λh;

[0095] Among them, Λh is the edge set that is currently in a non-operating state and has a closed-loop current that exceeds the limit.

[0096] It is worth noting that the embodiment of the present invention adopts the branch and bound method to solve the operation optimization model of the power grid in the above-mentioned region. Based on all the solved xm values ​​(the set of working states of all edges in the distribution network), an operation mode optimization scheme that minimizes the change in network state under a given maintenance plan can be obtained.

[0097] In order to further reflect the technical effect achieved by the method for optimizing the coordinated operation of the main and distribution networks of a regional power grid provided by the present invention, the technical effect of the present invention is described below in combination with an application example of optimizing the coordinated operation of the main and distribution networks of a regional power grid conducted by the inventor during the research and development process.

[0098] See also Figure 4, is a schematic diagram of another embodiment of the topological connection diagram of the regional power grid provided by the present invention.

[0099] Taking a certain actual regional power grid as an example, the operation mode optimization and power supply capacity analysis are carried out to verify the effectiveness of the method of the present invention. The regional power grid contains 2 500kV substations, 6 220kV substations, 16 110kV substations, 89 nodes and 125 edges. The topological connection diagram is shown in Figure 4 As shown, node 1, node 2 and node 7 contain power supplies with rated capacities of 3000MW, 2000MW and 20MW respectively, and r = 0.9. The load during the typical peak period of electricity consumption is analyzed, and the load of each node is shown in Table 1.

[0100] Table 1. Load of each node during peak hours

[0101]

[0102] The power limit and initial operation state of each edge are shown in Table 2, where 1 in the state column indicates an operation state and 0 indicates a non-operation state.

[0103] Table 2. Initial operating state and power limit of each edge

[0104]

[0105]

[0106] Assuming that the switch in edge 6-83, the line in edge 3-80, the transformer in edge 5-58, and the bus in node 11 need to be repaired, where edge 6-83 represents the edge connecting node 6 and node 83, the optimization calculation is performed according to the model in Section 2, and the operation mode adjustment results are shown in Table 3.

[0107] Table 2. Results of adjustment of the operation mode of each side

[0108]

[0109]

[0110] Combining Table 3 and Figure 4It can be seen that after the operation mode optimization, the nodes in the network that do not contain maintenance components are all connected to the power supply, and the network of the distribution network part is still open-loop operation, which meets the regional power grid topology characteristics. At the same time, the obtained fij is not overloaded in each component of the system. It is easy to verify that the obtained optimization results can minimize the change in the system operation mode. Taking the operation mode adjustment of the corresponding power station of nodes 47, 48, 49, 50, and 80 as an example, after the line 3-80 is overhauled and out of operation, considering changing the edge 47-48 to the operating state is the least operation method that can connect the load of the station to the power supply, but at this time the edge 3-47 will be overloaded; if only considering changing the edge 49-50 to the operating state, the load of the station can also be connected to the power supply, but at this time the edge 87-50 will be overloaded. In the operation mode optimization results of the method in this paper, the operation mode of the substation is adjusted to the exit of edge 49-80 and the switching of edges 47-48 and 49-50 to the operation state. By transferring the loads of node 48 and node 49 to edges 3-47 and 87-50 respectively, the heavy load or overload of the components is avoided as much as possible. This result verifies the effectiveness of the proposed operation mode optimization method.

[0111] In summary, the method for optimizing the coordinated operation of the main and distribution networks of a regional power grid provided by the embodiment of the present invention constructs a topological connection diagram of the regional power grid through the connection lines of the main grid and the distribution network, and the topological characteristics of the wiring in the distribution network substation, and takes the minimum adjustment of the grid operation mode as the optimization goal to establish an operation optimization model of the regional power grid with coordinated main and distribution networks. Compared with the prior art, the present invention can obtain a more reasonable and practical grid operation mode, thereby improving the efficiency and reliability of grid regulation and better meeting the application needs of the regional power grid.

[0112] See also Figure 5 , is a structural diagram of an embodiment of a regional power grid main distribution coordinated operation optimization system provided by the present invention.

[0113] The second aspect of the present invention provides a regional power grid main distribution coordinated operation optimization system, which is used to implement the regional power grid main distribution coordinated operation optimization method described in any embodiment of the first aspect, and the system includes:

[0114] A topology diagram construction module 11 is used to construct a topology connection diagram of the regional power grid based on the connection lines between the main grid and the distribution grid in the regional power grid, and the topological characteristics of the wiring in the distribution grid substation;

[0115] The state determination module 12 is used to determine the working state of each edge in the topology connection diagram before optimization; wherein the working state includes: an operating state or a non-operating state; the weight of the edge in the distribution network in the non-operating state is set to a small power value;

[0116] An optimization model building module 13 is used to build an operation optimization model of the regional power grid by minimizing the number of working state changes of all edges in the topological connection diagram as an objective function;

[0117] The optimization model solving module 14 is used to solve the operation optimization model, obtain the working state collection of all edges in the distribution network, and use the working state collection as the target operation mode of the distribution network.

[0118] It should be noted that the regional power grid main and distribution coordinated operation optimization system provided by the second aspect of the embodiment of the present invention can realize all the processes of the regional power grid main and distribution coordinated operation optimization method described in the first aspect of the embodiment. The functions of each module in the system and the technical effects achieved are respectively the same as the functions and technical effects achieved by the regional power grid main and distribution coordinated operation optimization method described in the first aspect of the embodiment, and will not be repeated here.

[0119] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for optimizing coordinated operation of main and distribution networks of a regional power grid, characterized in that: include: Based on the connection lines between the main network and the distribution network in the regional power grid, and the topological characteristics of the wiring in the distribution network substation, a topological connection diagram of the regional power grid is constructed; Determine the working state of each edge in the topology connection diagram before optimization; wherein the working state includes: an operating state or a non-operating state; the weight of the edge in the distribution network in the non-operating state is set to a small power value; Taking minimizing the number of working state changes of all edges in the topological connection graph as the objective function, an operation optimization model of the regional power grid is established; The operation optimization model is solved to obtain a collection of working states of all edges in the distribution network, and the collection of working states is used as a target operation mode of the distribution network.

2. The method for optimizing coordinated operation of the main distribution of the regional power grid according to claim 1, characterized in that: The topological characteristics of the wiring in the distribution network substation include: In the distribution network substation, each section of the bus is regarded as a node, and the equipment connected to the bus is regarded as an edge; wherein the bus includes: a high-voltage side bus and a low-voltage side bus.

3. The method for optimizing coordinated operation of the main distribution of the regional power grid according to claim 1, characterized in that: The nodes in the topological connection diagram include: a main grid substation node, a high-voltage side node and a low-voltage side node of the distribution grid substation; wherein the high-voltage side node is a high-voltage side bus node of the distribution grid substation; and the low-voltage side node is a low-voltage side bus node of the distribution grid substation.

4. The method for optimizing coordinated operation of the main distribution of the regional power grid according to claim 1, characterized in that: The working status of each edge of the main network is the same before and after optimization.

5. The method for optimizing coordinated operation of the main distribution of the regional power grid according to claim 1, characterized in that: The objective function is determined by the following formula: Among them, Z is the objective function; m is the edge number; Λo is the set of edges in the non-operating state before optimization; Λi is the set of edges in the operating state before optimization; xm is the working state of edge m, if it is in the operating state, xm=1, if it is in the non-operating state, xm=0.

6. The method for optimizing coordinated operation of the main distribution of the regional power grid according to claim 1, characterized in that: The operation optimization model is configured with a distribution network operation topology constraint set and a power grid operating characteristic constraint set; wherein, the distribution network operation topology constraint set is used to limit the number of edges in the distribution network in the operating state according to the operation topology rules of the distribution network; the power grid operating characteristic constraint set is used to limit the operating parameters of each edge and connection node in the operating state to meet the operating parameter rules of the regional power grid.

7. The method for optimizing coordinated operation of the main distribution of the regional power grid according to claim 6, characterized in that: The distribution network operation topology constraint condition set includes: distribution network open-loop operation topology constraint conditions and distribution network substation connection topology constraint conditions.

8. The method for optimizing coordinated operation of the main distribution of the regional power grid according to claim 7, characterized in that: The distribution network substation wiring topology constraints are as follows: Among them, m is the edge number; Λtm is the set of edges between the high-voltage side node and the low-voltage side node of the distribution network substation in the non-operating state; Λl is the set of edges in path l connecting the two high-voltage side busbars via the edge on the low-voltage side; Ll is the number of edges in path l; Γ is the set of path numbers connecting the two high-voltage side busbars via the edge on the low-voltage side; xm is the working state of edge m, if it is in the operating state, xm=1, if it is in the non-operating state, xm=0.

9. The method for optimizing coordinated operation of the main distribution of the regional power grid according to claim 6, characterized in that: The grid working characteristic constraint condition set includes: node power flow balance constraint condition, main grid substation overload constraint condition, node maximum output limit constraint condition, connection equipment limit constraint condition and loop limit constraint condition.

10. A regional power grid main distribution coordinated operation optimization system, characterized in that: include: A topology diagram construction module, used to construct a topology connection diagram of the regional power grid based on the connection lines between the main grid and the distribution grid in the regional power grid, and the topological characteristics of the wiring in the distribution grid substation; A state determination module, used to determine the working state of each edge in the topology connection diagram before optimization; wherein the working state includes: an operating state or a non-operating state; the weight of the edge in the distribution network in the non-operating state is set to a small power value; An optimization model building module, used to establish an operation optimization model of the regional power grid by minimizing the number of working state changes of all edges in the topological connection diagram as an objective function; The optimization model solving module is used to solve the operation optimization model, obtain the working state collection of all edges in the distribution network, and use the working state collection as the target operation mode of the distribution network.

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