Topology identification method for a power supply network for a ship

Abstract

This invention relates to a topology identification method for marine power supply networks. The power supply network includes circuit breakers controlling power generation facilities and bus tie, bridging, and side bridging circuit breakers interconnecting different areas of the network. The bus cables at both ends of the bus tie, bridging, and side bridging circuit breakers are simplified to busbar nodes, and the power generation facilities are simplified to generator unit nodes. For any busbar node, its potential busbar neighbor nodes and generator unit neighbor nodes are identified. Only one circuit breaker must exist between two nodes that are potential neighbors. All nodes are numbered in this way, and the power supply network topology is formed by all numbered busbar nodes and generator unit nodes. Two input matrices are defined: a busbar node neighbor matrix and a generator unit neighbor matrix. Drawing on the idea of ​​breadth-first search and layer-by-layer search, a network structure identification method is proposed. This method significantly reduces development time and improves accuracy.

Description

Technical Field

[0001] This invention relates to a power grid control technology, and more particularly to a topology identification method suitable for marine power supply networks. Background Technology

[0002] The generator sets and main switchboard section of a ship's electrical system are generally referred to as the power station. The main wiring diagram of a ship's power station refers to the circuit for receiving and distributing power, formed by switching equipment and connecting wires. The circuit diagram showing the generator and distribution equipment (symbols) connected by single lines is called the main electrical wiring diagram. In the main switchboard, the main wiring diagram of a ship's power station is represented by the connection method of the main busbars (hereinafter referred to as busbars). Typically, the number of busbars is small, and they are not segmented. For large cruise ships, multiple power stations are usually set up, and the busbars of each power station are segmented. Multiple power stations can supply power simultaneously or individually, enhancing the survivability of the ship. With the increase in generator capacity and load, ring or multi-ring ship power supply networks are becoming the trend.

[0003] Topology identification of complex power supply networks is a prerequisite for subsequent operations such as display, analysis, and control. Since ship power stations are mostly simple ring networks composed of single or dual power stations with few buses and generators, their network structure can be easily identified. However, with the increasing complexity of power supply networks, the emergence of multi-power station and multi-ring networks makes traditional manual traversal methods prone to omissions and errors in topology identification. Furthermore, the complex implementation of manual traversal methods makes topology identification of further complex power supply networks virtually impossible using manual methods. Therefore, there is an urgent need for efficient, accurate, and universal network structure identification algorithms that reduce development time while improving accuracy. Summary of the Invention

[0004] To address the challenges of topology identification in complex power supply networks, particularly those composed of multiple power stations and ring networks, a topology identification method suitable for marine power supply networks is proposed. This method draws upon the principles of breadth-first search and layer-by-layer search to design a topology identification approach applicable to complex marine power supply networks.

[0005] The technical solution of this invention is as follows: a topology identification method applicable to marine power supply networks. The power supply network includes circuit breakers for controlling power generation facilities and bus tie, bridging, and side bridging circuit breakers for interconnecting various areas of the power supply network. The bus cables at both ends of the bus tie, bridging, and side bridging circuit breakers are simplified to busbar nodes, and the power generation facilities are simplified to generator unit nodes. For any busbar node, its potential busbar neighbor nodes and generator unit neighbor nodes are identified. There must be only one circuit breaker between two nodes that are potential neighbors. All nodes are numbered in this way. The power supply network topology is composed of all numbered busbar nodes and generator unit nodes. The real-time node neighbor matrix is ​​equivalent to the switching status of the power supply network circuit breakers, i.e., the power supply status.

[0006] Furthermore, the topology of the power supply network includes M busbar nodes and N generator nodes. The busbar node neighbor matrix MP is an M×M matrix, and the generator node neighbor matrix JZ is an M×N matrix. Any element in the MP matrix represents the connected or disconnected state of two adjacent busbar nodes, and any element in the JZ matrix represents the connected or disconnected state of adjacent busbar nodes and generator nodes. The real-time circuit breaker switching state of the power supply network is converted into the busbar node neighbor matrix MP and the generator node neighbor matrix JZ.

[0007] Furthermore, the circuit breaker switch status is collected in real time and converted into the busbar node neighbor matrix MP and the unit node neighbor matrix JZ. All nodes connected together in the network are obtained through network structure identification methods, and the busbar node neighbor output matrix MPSC and the unit node neighbor output matrix JZSC are obtained for display, control and analysis of power supply status.

[0008] Furthermore, the network structure identification method specifically includes the following steps:

[0009] 4.1) Set a matrix whose size matches the network scale, and the elements in the matrix have unique initial values ​​based on the current circuit breaker state;

[0010] 4.2) Set initial empty sets A and J as intermediate processing sets; set initial empty set B to record the parent nodes that have been searched in the current step; set initial empty set C to record all parent nodes that have been searched; set set D to record the parent nodes to be searched in the next step, and initialize D = {1}, initially containing only element 1, indicating that the next search will start from parent node 1 by default; set loop variable I as the current number of times the search loop is performed, initially I = 1, and the loop condition is I ≤ M. Since the parent has only M nodes, proceed to step 4.3);

[0011] 4.3) The current set B is equal to the union of the current set D and the set B at the previous moment:

[0012] If I≤M and IC, it ensures that the parent node I to be processed in the I-th iteration has not appeared in the previous search; perform D=D∪{I}, that is, include the parent node I to be processed in this iteration into set D; perform B=D∪B, include set D into set B, and the next step is to determine if D is an empty set, which means there is no parent node to be searched in the next step, and go to step 4.5); if D is a non-empty set, then perform step 4.4) for each element in D.

[0013] 4.4) The parent node j starts from 1 to M, where Nu = Card(D) means that the number of elements in set D is recorded as Nu, and the loop variables i and j are initialized to 1; the loop conditions are i≤Nu and j≤M; the loop process is to record the current value j of the loop variable when MP{Di}j = 1 and record it in set A;

[0014] After this loop ends, set D is re-evaluated, D = AA ∩ B, which means that the elements in set D are all elements in set A but not in B. If none are found, the empty set is selected and the process proceeds to step 4.3. The search is performed on MP{Di}j, where Di represents the i-th element in set D. If MP{Di}j = 1, the value of j is re-recorded in set A, and set D is re-evaluated. The elements in set D are all elements in set A but not in B. If none are found, the empty set is selected and the process proceeds to step 4.3.

[0015] 4.5) Reassign values, C = B∪C, indicating that B is included in C. The output matrix MPSC of the parent row neighbor nodes is an M×M matrix, initially all matrix elements are 0. Nu1 = Card(B) takes the number of elements in B as Nu1. Initialize the loop variables i, j, k to 1, and perform loop assignment MPSC{Bi}{Bj} = 1, where Bi represents the i-th element in set B, and Bj represents the j-th element in set B; check the value of JZ{Bi}k, and the loop condition is k≤N, where N is Number of unit nodes; if JZ{Bi}k=1, then record the value of j in set J. The output matrix JZSC of the unit neighbor node is an M×N matrix. Initially, all matrix elements are 0. Take the number of elements in J as Nu2. Initialize the loop variables i and j to 1. JZSC{Bi}{Jj}=1, where Bi represents the i-th element in set B. Take all elements, where Jj represents the j-th element in set J. Take all elements. Reassign sets A, J, B, and D to empty sets and go to step 4.6).

[0016] 4.6) Increment the value of the loop variable I by 1, check if I is in set C. If it is, repeat step 4.6) until I equals M. Otherwise, element I belongs to set D and jump to step 4.3).

[0017] 4.7) Finally, the bus neighbor node output matrix MPSC and the unit neighbor node output matrix JZSC are obtained, which contain network topology information for input to other control logic.

[0018] The beneficial effects of this invention are as follows: This invention is applicable to the topology identification method of marine power supply networks. By inputting the circuit breaker's opening and closing status, an output matrix containing network topology information can be obtained. This network topology information can then be further displayed, analyzed, controlled, and performed on subsequent operations. Since marine power supply networks are becoming increasingly complex and often contain multiple ring networks, the above method can be used for different power supply network structures simply by changing the number of nodes and adjusting the node numbers according to the actual situation. This invention provides an efficient, accurate, and universal network structure identification method. It is more efficient than existing methods that manually traverse power supply network paths, and is suitable for topology identification of complex marine power supply networks. This invention significantly reduces development time while improving accuracy. Attached Figure Description

[0019] Figure 1 This is a schematic diagram illustrating the implementation principle of the method of the present invention;

[0020] Figure 2 A simplified diagram of the node simplification and numbering method of this invention;

[0021] Figure 3 This is a flowchart illustrating the implementation of the power grid network structure identification method of the present invention.

[0022] Figure 4 The flowchart for step 4.5 of the algorithm implementation process of this invention is shown. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0024] Breadth-First Search (BFS), also known as broadcast search, is a search strategy that starts from a source node *s* and searches for neighboring nodes sequentially or layer by layer until the target node is found. When the source node *s* applies BFS to find a specified node in the network, it first queries all its neighboring nodes to see if they are the target node. If they are, the search stops; otherwise, the node continues to pass the query to its neighbors until the target node is found. However, realizing the network topology requires obtaining the interconnection information of all nodes. This invention borrows the idea of ​​BFS to sequentially or layer by layer find neighboring nodes and proposes an efficient, accurate, and universal method for identifying network structure.

[0025] like Figure 1 The diagram illustrates the implementation principle of the method of this invention. It collects the switching status of all circuit breakers in the power supply network. These circuit breakers include those controlling whether power generation facilities are connected to the grid, such as those for diesel generator sets, shore power, and steam turbine generator sets. They also include bus tie, bridging, and side bridging circuit breakers that interconnect different areas of the power supply network. This circuit breaker switching status information is crucial input for power supply network topology identification.

[0026] Based on the known overall power supply network structure, the bus cables connected to both ends of the bus tie, bridging, and side bridging circuit breakers are simplified to busbar nodes, and the power generation facilities are simplified to unit nodes. See the diagram for specific node simplification and numbering methods. Figure 2 Once the node numbers in the power supply network are fixed, for any busbar node, its potential busbar neighbor nodes and generator neighbor nodes can be identified. Two nodes that are potential neighbors must have only one circuit breaker between them. When that circuit breaker is closed, the two nodes become neighbors. Therefore, the circuit breaker switching states can be converted into a busbar node neighbor matrix (MP) and a generator node neighbor matrix (JZ). The matrix size is related to the number of busbar nodes and generator nodes. For example, in a complex power supply network with M busbar nodes and N generator nodes, its busbar node neighbor matrix (MP) is an M×M matrix, and its generator node neighbor matrix (JZ) is an M×N matrix. Figure 2 For example, if the bridging circuit breaker 1 is closed, then busbar node 1 and busbar node 2 are connected and considered as neighbors. Then the element MP in the matrix... 12 With MP 21 If all are set to 1, and the generator 1 circuit breaker is closed, then busbar node 2 is connected to unit node 1, and they are considered as neighboring nodes. Then JZ 21 The value is 1.

[0027] The power grid network structure identification method is used to process the bus neighbor node matrix (MP) and generator neighbor node matrix (JZ) obtained above to produce output matrices containing network topology information: the bus neighbor output matrix (MPSC) and the generator neighbor output matrix (JZSC). These two matrices can be used to parse out all bus nodes and generator nodes interconnected with any given bus node. The network topology output matrices can be processed according to actual needs, and the processing results can be transmitted to other functional modules for control, analysis, or display operations.

[0028] Figure 3 The flowchart is a newly designed method of this invention. The new method involves defining two matrices and performing a series of processes, drawing on the idea of ​​layer-by-layer search, to obtain all connected nodes in the network, thus realizing a new power grid network identification method.

[0029] At any given moment, some circuit breakers in the power grid are closed while others are open. These different closing and opening states constitute a network topology. The method of this invention directly identifies interconnected busbars and generating units by inputting the closing and opening states of each switch. For example, if a switch is closed, we only know that switches 1 and 2 are connected, 2 and 3 are connected, and 3 and 4 are connected. Using this method, we can determine that switches 1, 2, 3, and 4 are connected together. This process is relatively difficult to implement for complex networks. Steps 4.1-4.7 describe the implementation process of this power grid network structure identification method.

[0030] 4.1 Assuming there are a total of M busbar nodes and N generator unit nodes, the busbar neighbor node matrix (MP) is an M×M matrix and the generator unit neighbor node matrix (JZ) is an M×N matrix.

[0031] Set a matrix whose size matches the network size, and whose elements have unique initial values ​​based on the current circuit breaker state.

[0032] 4.2. Set initial empty sets A and J as intermediate processing sets; set initial empty set B to record the parent nodes already searched in the current step; set initial empty set C to record all parent nodes already searched; set set D to record the parent nodes to be searched in the next step, and initialize D = {1}, initially containing only element 1, indicating that the next search will start from parent node 1 by default; set loop variable I as the current number of times the search loop is performed, initially I = 1, and the loop condition is I ≤ M. Since the parent node only has M nodes, proceed to step 4.3.

[0033] 4.3 The current set B is equal to the union of the current set D and the set B at the previous moment.

[0034] If I ≤ M and IC, it ensures that the parent node I to be processed in the I-th iteration has not appeared in previous searches. Perform D = D∪{I} to include the parent node I to be processed in this iteration into set D. Perform B = D∪B to include set D into set B. The next step is to determine if D is empty, meaning there are no parent nodes to be searched in the next step, and proceed to step 4.5. If D is not empty, then for each element in D, execute step 4.4.

[0035] 4.4. The parent node j starts from 1 to M, where Nu = Card(D) represents the number of elements in set D, denoted as Nu. The loop variables i and j are initialized to 1. The loop conditions are i ≤ Nu and j ≤ M. The loop process records the current loop variable value j when MP{Di}j = 1 and adds it to set A. After this loop ends, set D is re-evaluated, D = AA ∩ B, meaning that set D contains all elements in set A but not in B. If none are found, the set is empty, and the process returns to step 4.3 to search for MP{Di}j. Di represents the i-th element in set D (initially, D only contains 1, but after step 4.4, D is re-evaluated, changing the elements within D). If MP{Di}j = 1, the value of j is re-recorded in set A, and set D is re-evaluated, containing all elements in set A but not in B. If none are found, the set is empty, and the process returns to step 4.3.

[0036] 4.5. Reassign values: C = B∪C, meaning B is included in C. The output matrix of the neighboring nodes of the mother row (denoted as MPSC) is an M×M matrix, initially with all elements set to 0. Nu1 = Card(B) takes the number of elements in B as Nu1. Initialize the loop variables i, j, k to 1, and perform the loop assignment MPSC{Bi}{Bj} = 1, where Bi represents the i-th element in set B, and Bj represents the j-th element in set B. Check the value of JZ{Bi}k, and the loop condition is k≤N, where N is the number of nodes in the unit. If JZ{Bi}k=1, then record the value of j in set J. The output matrix of the unit's neighbor node (denoted as JZSC) is an M×N matrix, initially all matrix elements are 0. Take the number of elements in J as Nu2, initialize loop variables i and j to 1, JZSC{Bi}{Jj}=1, where Bi represents the i-th element in set B, take all elements, where Jj represents the j-th element in set J, take all elements, reassign sets A, J, B, and D to empty sets, and go to step 4.6. The flowchart of this step is as follows. Figure 4 As shown.

[0037] 4.6 Increment the value of the loop variable I by 1, and check if I is in set C. If it is, repeat step 4.6 until I equals M. Otherwise, element I belongs to set D and jump to step 4.3.

[0038] 4.7 Finally, the bus neighbor node output matrix (MPSC) and the unit neighbor node output matrix (JZSC) can be obtained. The network topology information contained therein can be used as input for other control logic and as input for the next control operation.

[0039] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A topology identification method for marine power supply networks, the power supply network including circuit breakers for controlling power generation facilities and bus tie, bridging, and side bridging circuit breakers for interconnecting various areas of the power supply network, characterized in that, 1) Simplify the bus cables at both ends of the bus tie circuit breaker, bridging circuit breaker, and side bridging circuit breaker in the marine power supply network to busbar nodes, and simplify the power generation facilities to unit nodes; 2) Based on the real-time collected circuit breaker switch status, construct the busbar node neighbor matrix MP and the unit node neighbor matrix JZ, where: The neighbor matrix MP of the mother row nodes is an M×M matrix. In the MP matrix, the element MP(i,j)=1 indicates that the mother row nodes i and j are directly connected through a single switch. The unit node neighbor matrix JZ is an M×N matrix. In the JZ matrix, the element JZ(i,k)=1 indicates that the bus node i and the unit node k are directly connected through a single switch. 3) Based on the breadth-first search algorithm, the MP and JZ matrices are traversed to dynamically generate the bus neighbor output matrix MPSC and the unit neighbor output matrix JZSC, which are used to identify the topology of the marine power supply network in real time.

2. The topology identification method for marine power supply networks according to claim 1, characterized in that, The power supply network topology includes M busbar nodes and N generator nodes. The busbar node neighbor matrix MP is an M×M matrix, and the generator node neighbor matrix JZ is an M×N matrix. Any element in the MP matrix represents the connected or disconnected state of two adjacent busbar nodes, and any element in the JZ matrix represents the connected or disconnected state of adjacent busbar nodes and generator nodes. The real-time circuit breaker switching state of the power supply network is converted into the busbar node neighbor matrix MP and the generator node neighbor matrix JZ.

3. The topology identification method for marine power supply networks according to claim 2, characterized in that, The circuit breaker switch status is collected in real time and converted into busbar node neighbor matrix MP and unit node neighbor matrix JZ. All nodes connected together in the network are obtained through network structure identification methods, and the busbar node neighbor output matrix MPSC and unit node neighbor output matrix JZSC are obtained for display, control and analysis of power supply status.

4. The topology identification method for marine power supply networks according to claim 3, characterized in that, The network structure identification method specifically includes the following steps: 4.1) Set a matrix whose size matches the network scale, and the elements in the matrix have unique initial values ​​based on the current circuit breaker state; 4.2) Set initial empty sets A and J as intermediate processing sets; set initial empty set B to record the parent nodes that have been searched in the current step; set initial empty set C to record all parent nodes that have been searched; set set D to record the parent nodes to be searched in the next step, and initialize D = {1}, initially containing only element 1, indicating that the next search will start from parent node 1 by default; Set the loop variable I as the current number of times the search loop is performed. Initially, I = 1. The loop condition is I ≤ M. Since the parent row only has M nodes, proceed to step 4.

3. 4.3) The current set B is equal to the union of the current set D and the set B at the previous moment: If I≤M, and This means ensuring that the parent node I to be processed in the I-th iteration has not appeared in the previous search; performing D = D∪{I}, that is, including the parent node I to be processed in this iteration into set D; performing B = D∪B, including set D into set B; the next step is to determine if D is an empty set, which means there is no parent node to be searched in the next step, and go to step 4.5); if D is a non-empty set, then perform step 4.4 for each element in D. 4.4) The parent node j starts from 1 to M, where Nu = Card(D) means that the number of elements in set D is recorded as Nu, and the loop variables i and j are initialized to 1; the loop conditions are i≤Nu and j≤M; the loop process is to record the current value j of the loop variable when MP{Di}j = 1 and record it in set A; After this loop ends, set D is re-evaluated, D = AA ∩ B, which means that the elements in set D are all elements in set A but not in B. If none are found, the empty set is selected and the process proceeds to step 4.

3. The search is performed on MP{Di}j, where Di represents the i-th element in set D. If MP{Di}j = 1, the value of j is re-recorded in set A, and set D is re-evaluated. The elements in set D are all elements in set A but not in B. If none are found, the empty set is selected and the process proceeds to step 4.

3. 4.5) Reassign values, C = B∪C, indicating that B is included in C. The output matrix MPSC of the parent row neighbor nodes is an M×M matrix, initially all matrix elements are 0. Nu1 = Card(B) takes the number of elements in B as Nu1. Initialize the loop variables i, j, k to 1, and perform loop assignment MPSC{Bi}{Bj} = 1, where Bi represents the i-th element in set B, and Bj represents the j-th element in set B; check the value of JZ{Bi}k, and the loop condition is k≤N, where N is Number of unit nodes; if JZ{Bi}k=1, then record the value of j in set J. The output matrix JZSC of the unit neighbor node is an M×N matrix. Initially, all matrix elements are 0. Take the number of elements in J as Nu2. Initialize the loop variables i and j to 1. JZSC{Bi}{Jj}=1, where Bi represents the i-th element in set B. Take all elements, where Jj represents the j-th element in set J. Take all elements. Reassign sets A, J, B, and D to empty sets and go to step 4.6). 4.6) Increment the value of the loop variable I by 1, check if I is in set C. If it is, repeat step 4.6) until I equals M. Otherwise, element I belongs to set D and jump to step 4.3). 4.7) Finally, the bus neighbor node output matrix MPSC and the unit neighbor node output matrix JZSC are obtained, which contain network topology information for input to other control logic.

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