Network architecture design and power flow optimal distribution method and device considering fault and system reconstruction

Abstract

The invention discloses a network architecture design and power flow optimal distribution method and device considering faults and system reconstruction, and relates to the technical field of aircrafts. The method comprises the steps of obtaining parameter data of an aircraft power supply system; according to the parameter data, performing equivalent processing on each component in the aircraft power supply system based on an electric network theory, and searching a power grid framework according to a constraint condition to obtain the power grid framework; based on a power grid architecture, considering the influence of a fault on a power supply path, and performing path search on all bus bars under normal and fault conditions by adopting a deep search algorithm; and determining the reliability according to the power supply path, and judging whether the reliability constraint of each bus bar is satisfied, if not, carrying out grid architecture weak node identification and power supply redundancy adjustment, and if yes, carrying out branch power flow distribution and weight loss optimization processing on the grid architecture, and determining a distribution scheme. The invention aims to realize the network topology design of the aircraft power supply system and improve the performance of the aircraft power supply system.

Description

Technical Field

[0001] The present application relates to the technical field of aircraft, and particularly to a network architecture design and power flow optimal allocation method and device considering faults and system reconstruction. Background Technique

[0002] With the development of aircraft more-electric / fully-electric, the increase in the number of airborne electric loads, and the rapid increase in energy demand, electric energy has gradually become the main form of the aircraft energy system. The extensive application of electric loads has brought great challenges to the aircraft power system, and thus has brought significant changes to the aircraft power supply system and distribution system. The design of the electric aircraft power supply system integrates the aircraft power supply and the power transmission and distribution devices into a whole, which is related to the performance of the system such as reliability, weight, loss, and stability, and is the guarantee for the coordinated operation of each component of the system. Therefore, it is a key technology of the aircraft power supply system.

[0003] After the performance indicators of the aircraft are decomposed downward in the traditional aircraft power supply system architecture design, each system conducts independent design using different methods and tools. The assumed conditions and design points required for system design usually come from the experience of previous products; during the integration process, information interaction between devices and systems from different suppliers is achieved through manual and document forms.

[0004] This kind of local design cannot maximize the utilization of system performance, and may also lead to one-sidedness and conservatism in system design. Moreover, the design based on experience is not suitable for the innovative application of new technologies and cannot meet the complex mission requirements of future aircraft. Therefore, a design method needs to be proposed to reduce the design difficulty, cost, and development cycle, and improve the scientific nature and independent innovation ability of the design.

[0005] In addition, reliability is a key issue focused on in the aircraft power supply system architecture design, and weight and loss are also crucial for affecting aircraft performance. However, most of the existing work on this topic focuses on system reliability assessment, and the requirements of different mission stages and dynamic processes such as fault reconstruction in the system for the power grid architecture design and the impact on system weight, loss, and reliability indicators are not considered during this process. Summary of the Invention

[0006] The purpose of the present application is to provide a network architecture design and power flow optimal allocation method and device considering faults and system reconstruction, which can realize the network topology design of the aircraft power supply system and improve the performance of the aircraft power supply system.

[0007] To achieve the above purpose, the present application provides the following solutions:

[0008] In the first aspect, the present application provides a network architecture design and power flow optimal allocation method considering faults and system reconstruction, including:

[0009] Obtain parameter data of the aircraft power supply system; the parameter data includes: load power, energy type and quantity, number of busbars in the architecture, power supply system, and initial failure rates of various components of the aircraft power supply system;

[0010] According to the parameter data, based on electrical network theory, perform equivalent processing on each component in the aircraft power supply system, and search for the power grid architecture according to the constraint conditions to obtain the power grid architecture; the equivalent processing includes: regarding generators, busbars, and energy storage devices as nodes, and converters and contactors as edges, and representing the connection relationships between nodes in the form of an adjacency matrix; the constraint conditions include: network node constraints and network connection relationship constraints;

[0011] Based on the power grid architecture, considering the impact of single-point and multi-point failures on the system, use a depth search algorithm to perform path search according to the power supply logic constraints to obtain the power supply path; the power supply path is the path from the power source node to each busbar node;

[0012] Determine the reliability according to the power supply path; the reliability includes: basic reliability and mission reliability; the basic reliability is the durability and failure rate of the aircraft power supply system during use; the mission reliability is the probability that even if some components fail during the flight mission, the mission can still be successfully completed and the aircraft can land safely;

[0013] Based on the reliability and the reliability constraints of each busbar, perform branch power flow distribution and weight loss optimization processing on the power grid architecture to determine the distribution plan; the distribution plan is used to improve the performance of the aircraft power supply system.

[0014] In a second aspect, the present application provides a network architecture design and power flow optimization distribution device considering faults and system reconstruction, including:

[0015] A parameter data acquisition module for acquiring parameter data of the aircraft power supply system; the parameter data includes: load power, energy type and quantity, number of busbars in the architecture, power supply system, and initial failure rates of various components of the aircraft power supply system;

[0016] A power grid architecture determination module for, according to the parameter data, performing equivalent processing on each component in the aircraft power supply system based on electrical network theory, and searching for the power grid architecture according to the constraint conditions to obtain the power grid architecture; the equivalent processing includes: regarding generators, busbars, and energy storage devices as nodes, and converters and contactors as edges, and representing the connection relationships between nodes in the form of an adjacency matrix; the constraint conditions include: network node constraints and network connection relationship constraints;

[0017] A path search module, which is used to consider the impact of single-point and multi-point faults on the system based on the power grid architecture, and perform path search according to the power supply logic constraints by using a depth search algorithm to obtain a power supply path; the power supply path is a path from a power source node to each bus bar node;

[0018] A reliability determination module, which is used to determine the reliability according to the power supply path; the reliability includes: basic reliability and mission reliability; the basic reliability is the durability and failure rate of the aircraft power supply system during use; the mission reliability is the probability that the mission can still be successfully completed and the aircraft can land safely even if some components fail during the flight mission;

[0019] An optimization processing module, which is used to perform branch power flow distribution and weight loss optimization processing on the power grid architecture based on the reliability and the reliability constraints of each bus bar, and determine a distribution plan; the distribution plan is used to improve the performance of the aircraft power supply system.

[0020] According to the specific embodiments provided by the present application, the present application has the following technical effects:

[0021] The present application provides a method and device for network architecture design and power flow optimization distribution considering faults and system reconstruction. By obtaining the parameter data of the aircraft power supply system; according to the parameter data, each component in the aircraft power supply system is equivalently processed based on the electrical network theory, and the power grid architecture is searched according to the constraint conditions to obtain the power grid architecture; based on the power grid architecture, considering the impact of single-point and multi-point faults on the system, a depth search algorithm is used to perform path search according to the power supply logic constraints to obtain a power supply path; the reliability is determined according to the power supply path, and based on the reliability and the reliability constraints of each bus bar, branch power flow distribution and weight loss optimization processing are performed on the power grid architecture to determine a distribution plan. The present application not only covers the design of the topology structure of the aircraft power supply system, but also comprehensively considers key elements such as fault mode analysis, reliability evaluation, and branch power distribution. This optimization design process can optimize the system weight and loss on the basis of improving the reliability, safety, and stability of the aircraft power supply system, ensuring that the system can operate stably and efficiently under various working conditions. Therefore, the present application can realize the network topology design of the aircraft power supply system and improve the performance of the aircraft power supply system. Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0023] Figure 1Flowchart of a network architecture design and power flow optimal allocation method considering faults and system reconstruction;

[0024] Figure 2 Design block diagram of a network architecture design and power flow optimal allocation method considering faults and system reconstruction;

[0025] Figure 3 Algorithm flowchart of a network architecture design and power flow optimal allocation method considering faults and system reconstruction. Specific implementation manners

[0026] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0027] To make the above objects, features, and advantages of the present application more obvious and understandable, the present application will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0028] In an exemplary embodiment, as Figure 1 shown, a network architecture design and power flow optimal allocation method considering faults and system reconstruction is provided. The network architecture design and power flow optimal allocation method considering faults and system reconstruction includes:

[0029] Step 100: Obtain the parameter data of the aircraft power supply system. The parameter data includes: load power, energy type and quantity, number of busbars in the architecture, power supply system, and initial failure rates of each component of the aircraft power supply system.

[0030] Step 200: Based on the parameter data, perform equivalent processing on each component in the aircraft power supply system according to the electrical network theory, and search for the power grid architecture according to the constraint conditions to obtain the power grid architecture. The equivalent processing includes: regarding generators, busbars, and energy storage devices as nodes, and converters and contactors as edges, and representing the connection relationship between each node in the form of an adjacency matrix; the constraint conditions include: network node constraints and network connection relationship constraints.

[0031] Step 300: Based on the power grid architecture, considering the impact of single-point and multi-point faults on the system, use a depth search algorithm to perform path search according to the power supply logic constraints to obtain the power supply path. The power supply path is the path from the power source node to each busbar node.

[0032] Based on the power grid architecture, using a depth search algorithm to perform path search according to the power supply logic constraints to obtain the power supply path, specifically including:

[0033] Using the method of permutation and combination, fault combinations are determined based on the power grid architecture; among them, the power grid architecture includes n architectures; each architecture has p edges with faults, and based on the p edges with faults, 2 p fault combinations can be generated.

[0034] For any architecture, fault injection is performed on each fault combination, and in the power grid architecture after fault injection, path search is performed based on the depth-first search algorithm according to the power supply logic constraints to obtain the power supply path; among them, let C’ be the adjacency matrix after fault injection, for all busbar nodes v∈V load , if there is no path from the power supply node u∈V Source to v, it indicates that the architecture cannot supply power to the busbar node during normal and faulty conditions and does not meet the power supply logic constraints; then:

[0035]

[0036] Among them, V load is the set of all busbar nodes; V Source is the set of all power supply nodes; P u,v is the path from the power supply node u to the busbar node v; V is the set of all nodes in the power grid architecture. Usually, the nodes in the power grid can include power supply nodes, load nodes (busbar nodes), and energy storage nodes; C′ u,v is the adjacency matrix element of the power supply node u and the busbar node v after fault injection.

[0037] Step 400: Determine the reliability according to the power supply path. The reliability includes: basic reliability and mission reliability; the basic reliability is the durability and failure rate of the aircraft power supply system during use; the mission reliability is the probability of successfully completing the mission and safely landing even if some components fail during the flight mission.

[0038] The mission reliability includes: busbar power supply mission reliability; among them, the calculation formula for the busbar power supply mission reliability is:

[0039]

[0040] Among them, R task_l is the busbar power supply mission reliability; l is the busbar serial number; Etemp jk is the disjoint branch composed of node j and node k; R(·) is the reliability function; R(Etemp jk ) is the reliability corresponding to the disjoint branch composed of node j and node k; Etemp is the minimum path set of the disjoint branch.

[0041] Step 500: Based on the reliability and the reliability constraints of each busbar, perform branch power flow distribution and weight loss optimization on the power grid architecture to determine the distribution plan. The distribution plan is used to improve the performance of the aircraft power supply system.

[0042] Based on the reliability and the reliability constraints of each busbar, perform branch power flow distribution and weight loss optimization on the power grid architecture to determine the distribution plan, specifically including:

[0043] Judge whether the reliability meets the reliability constraints of each busbar to obtain the first judgment result.

[0044] If the first judgment result is negative, then judge whether the power supply redundancy of the power grid architecture reaches the set threshold to obtain the second judgment result.

[0045] If the second judgment result is positive, then adjust the reliability based on the reliability correction factor and return to "Judge whether the reliability meets the reliability constraints of each busbar to obtain the first judgment result".

[0046] If the second judgment result is negative, then update the power grid architecture by increasing structural redundancy.

[0047] If the first judgment result is positive, then perform branch power flow distribution and weight loss optimization on the power grid architecture to determine the distribution plan.

[0048] Update the power grid architecture by increasing structural redundancy, and the formula used is:

[0049] C″ i =C i +ΔC i .

[0050] Among them, C″ i is the updated power grid architecture; C i is the adjacency matrix; ΔC i is the new redundant path matrix corresponding to the increased structural redundancy.

[0051] Adjust the reliability based on the reliability correction factor, and the formula used is:

[0052]

[0053] Among them, is the adjusted reliability; α v is the reliability correction factor; R v is the reliability.

[0054] Perform branch power flow distribution and weight loss optimization on the power grid architecture to determine the distribution plan, specifically including:

[0055] According to the power grid architecture, based on the power demand of the load nodes, determine the branch power configuration to perform branch power flow distribution; based on the branch power configuration, according to the component power density and efficiency, determine the weight and energy loss to perform weight loss optimization processing.

[0056] The calculation formula for the branch power configuration is:

[0057]

[0058] Wherein, is the branch power configuration; F j is the fault combination; is the power configuration demand of node j under the fault combination F j ; is the set of fault combinations; P v is the power demand of the load node; v is the bus node; V load is the set of all bus nodes; A u,v is the element of the adjacency matrix.

[0059] According to the different types of node j and node i, the weight W ij of the branch formed by node j and node i is expressed as:

[0060]

[0061] Wherein, W i is the weight of the device corresponding to node i; C ij is the adjacency matrix corresponding to node i and node j; W Swi_ij is the weight of the switch in the branch formed by node j and node i; W Ca_ij is the weight of the cable in the branch formed by node j and node i; V i is the node voltage corresponding to node i; V j is the node voltage corresponding to node j; W Con_ij is the weight of the converter in the branch formed by node j and node i; N G is the number of generators; N FC is the number of fuel cells; N l is the number of busbars.

[0062] This application adopts the design principles of "top - down" and "bottom - up", and solves the design problem step - by - step in series, and conducts optimization and allocation of the system task reliability. First, calculate the reliability of each component based on the initial failure rate of the component, and conduct a search for the power grid architecture that meets the constraints to generate a power grid architecture that meets the conditions. Considering the impact of single - point and multi - point failures on the system, use the permutation and combination method to generate possible failure combinations, and then traverse each failure combination in this set in turn. Inject the failure branch signal into the system network topology adjacency matrix during normal operation to obtain the system network connection relationship during failure. Then, based on the depth - first search algorithm, obtain all power supply paths that meet the power supply capacity constraints for each load node. Calculate the task reliability of each busbar in the system based on the power supply paths, and judge whether it meets the design requirements. If the task reliability of the busbar fails to meet the reliability constraints of each busbar, identify the weak nodes in the system, and update the power grid architecture by increasing the redundancy of the system architecture and recalculate. When the system architecture has reached the maximum power supply redundancy, it indicates that the failure rate of the components in the system cannot meet the requirements. Therefore, it is necessary to adjust the component reliability based on the component reliability correction factor. If the power supply task reliability of the busbar meets the reliability constraints in the design, based on the determined network structure and system power demand, optimize the possible working states of the system, clarify the power configuration of each branch, and then calculate the overall weight and energy loss of the system. The design process is continuously optimized and iterated to obtain the optimal architecture of weight, loss and reliability.

[0063] This application forms a set of "V" - shaped systematic optimization design processes for the power grid architecture of the aircraft power supply system. This process not only considers the topological structure design of the power supply system, but also comprehensively considers key elements such as failure mode analysis, reliability assessment and component reliability allocation, and considers the impact of architecture failure reconstruction on the branch power flow, and conducts optimization based on weight, loss and reliability.

[0064] Conduct a search for the power grid architecture that meets the constraints to generate a power grid architecture that meets the conditions. Specifically, first determine the types and quantities of energy sources and loads, collect the initial failure rates of each component, and obtain the task profile of the load as input parameters. On this basis, considering various constraints in the system design, such as design experience, power supply capacity, reliability and airworthiness standards, etc., adopt the "top - down" forward design method to establish a topology - based design model and generate a set of architectures that meet all constraints.

[0065] In the constraint conditions of the power supply function, comprehensively consider the impact of single-point and multi-point failures in the system on the power supply capacity. For each architecture in the architecture set, randomly generate failures, traverse all possible failure modes, and evaluate whether the busbars in the system can maintain uninterrupted power supply under these failure modes. If a certain architecture in the power grid architecture cannot meet the power supply requirements under any failure, it proves that this architecture cannot meet the power supply requirements, and then update the power grid architecture.

[0066] For the architectures that meet the power supply path requirements, further calculate their basic reliability and mission reliability. Evaluate the reliability level of the system when performing specific tasks. Through quantitative analysis, provide an objective evaluation of the reliability of different architectures.

[0067] Based on the sensitivity analysis of the parameters of each component in the power grid architecture, identify the weak nodes of the system that may lead to a decrease in overall reliability. This step is to identify the key nodes in the aircraft power supply system that may lead to a decrease in overall reliability. On this basis, improve the redundancy of the weak nodes in the aircraft power supply system to improve the system reliability.

[0068] On the basis of generating the power grid architecture, considering the key factor that failures occurring at different positions in the aircraft power supply system will lead to the reconstruction of the system power supply path, which in turn affects the power of each branch, carry out multi-objective optimization with the goals of minimizing system weight, loss and maximizing reliability, and obtain the comprehensive optimal architecture.

[0069] The purpose of this application is to realize the network topology design of the aircraft power supply system for any design requirements. Consider the impact of fault reconstruction on the power supply path, and effectively improve the system resilience by identifying the weak nodes in the aircraft power supply system and optimizing the reliability allocation of components, so as to improve the reliability of the entire system. And consider the impact of architecture fault reconstruction on the branch power flow, and carry out optimization based on weight, loss and reliability.

[0070] Mainly adopt the "top-down" and "bottom-up" V-shaped design principles, solve the design problems step by step in series and carry out optimization, as Figure 2 shown. The corresponding specific algorithm flow is as Figure 3 shown. The optimal design and allocation algorithm of the power grid can be divided into the following four sub-problems. Combine Figure 2 with Figure 3 to elaborate on this process in detail.

[0071] Step 1, namely LV1: Solve the constraint satisfaction problem.

[0072] (1) First, determine parameters such as the load power required for the architecture design, the type and quantity of energy sources, the number of busbars in the architecture, the corresponding power supply system, and the initial failure rates of each component. These will be used as inputs to the algorithm. On this basis, considering various constraints in the architecture design, regard the entire architecture design process as a process of connecting each node with directed edges.

[0073] The constraints in the architecture design can be mainly divided into three categories, including network node constraints, network connection relationship constraints, and system power supply logic constraints. In LV1, mainly consider meeting the network node constraints and network connection relationship constraints, while the satisfaction of the power supply logic constraints is mainly verified in LV2. The specific constraints in the architecture design are as follows:

[0074] ① Network node constraints.

[0075] 1) In the aircraft power supply system, the generator power supply device is a unidirectional power supply component and only has the ability to output power.

[0076] 2) The energy storage in the aircraft power supply system is an emergency power supply, mounted on the 28V busbar, and only has the ability to output power.

[0077] 3) In the aircraft power supply system, conversion devices represented by busbars, SSPCs, and converters must have both inputs and outputs simultaneously.

[0078] 4) According to the importance of the loads in the aircraft power supply system, the busbars are divided into general busbars and important busbars, and power can only flow from the general busbar to the important busbar.

[0079] 5) According to the busbar power supply system, clarify the power supply network levels among the busbars, C_270VDC < C_115VAC < C_28VDC, and power can only flow from the busbar with a lower level to the busbar with a higher level.

[0080] 6) The power supply network balance constraint in the aircraft power supply system, that is, the difference between the input and output degrees of each node at the same level < 1.

[0081] ② Network connection relationship constraints.

[0082] 1) The power supply node and the load node cannot be directly connected.

[0083] 2) The power supply node can only be connected to the main busbar and cannot be connected to the busbars of other power supply levels.

[0084] 3) During the operation of the system, the power of any node is balanced.

[0085] 4) During normal operation, the main power supplies in the system do not supply power in parallel.

[0086] ③ Power supply logic constraints.

[0087] 1) When a generator fails in the aircraft power supply system, if the number of failures is less than the number of generators, it is necessary to ensure that all busbar nodes have a power supply path, and at this time, the ram air turbine generator (RAT) is not put into operation.

[0088] 2) When a generator fails in the aircraft power supply system, if the number of failures is equal to the number of generators, it is necessary to ensure that all emergency busbars are powered, and at this time, the RAT is put into operation.

[0089] 3) If both the generator and the RAT in the aircraft power supply system fail simultaneously, at this time, the battery Bat is put into operation, and it is necessary to ensure the power supply of the 28V emergency busbar.

[0090] (2) During the process of generating the architecture, each component in the system is equivalent based on the point network theory. Among them, generators, busbars, energy storage devices, etc. can be regarded as nodes, and converters, contactors, etc. are equivalent to edges. The connection relationship between each node is represented in the form of an adjacency matrix. On this basis, the power grid architecture is searched to ensure that all constraint conditions are met, and finally a set containing all feasible architectures is generated.

[0091] Specifically, through searching, n architectures A1, A2,..., A n , each architecture A i 's adjacency matrix is represented by C i , where C i ∈R m×m is an m×m matrix, representing the connection relationship between the nodes of the architecture. m is the number of nodes in each architecture. 1 ≤ i ≤ n. i is the serial number.

[0092] The set C containing all feasible architectures is a three-dimensional vector, C ∈ R n×m×m , where n in the first dimension represents the number of architectures that meet the constraints; the second and third dimensions are both m, representing the dimension of each adjacency matrix, that is, the number of nodes in each architecture.

[0093] Step 2, namely LV2: Generate the working state based on fault reconstruction. While satisfying the node constraints of the architecture network and the network connection relationship constraints, further consider the impact of faults occurring in the system on the power supply capacity of the architecture, and then verify whether the architecture meets the power supply logic constraints.

[0094] The algorithms adopted in this part mainly include the generation of fault combinations, the traversal and injection process of single-architecture faults, and the power supply path search based on the depth-first search (DFS) algorithm.

[0095] (1) Generation of fault combinations. Assume that each architecture A iThere are p possible fault paths (i.e., the number of edges where faults can occur), and these fault paths are represented by a set of node pairs {(u1,v1),(u2,v2),…,(u p ,v p )}, where each node pair (u k ,v k ) represents an edge that can fail. All combinations of these faults are generated using the method of permutations and combinations. Specifically, for each node pair, it can be selected whether to inject a fault. For p edges, these possible fault scenarios can be represented by generating 2 p different fault combinations.

[0096] Specifically, let the fault combination be , where each fault combination F j ∈{0,1} P indicates whether each edge fails. If F j,k =1, it means that the edge formed by node j and node k fails; if F j,k =0, it means that the edge formed by node j and node k is working properly.

[0097] (2) Fault traversal and injection. For each architecture in the set C of architectures, fault injection is performed on each fault combination F j in turn, and the specific process is as follows:

[0098] ① Assume that C i is the adjacency matrix of architecture A i when it is working properly.

[0099] ② For each fault combination F j =(F j,1 , F j,2 ,…,F j,p ), construct a fault indication matrix F j′ ∈R m×m , where:

[0100]

[0101] Among them, and are both standard basis vectors, indicating 1 at the u k and v k positions and 0 at other positions. Through the outer product operation, the fault indication matrix F j′ represents the edges disconnected under the fault combination F j .

[0102] ③ The adjacency matrix after fault injection can be obtained by subtracting the fault indication matrix F i from C j′Element-wise multiplication results in:

[0103]

[0104] Among them, represents element-wise multiplication. The adjacency matrix after fault injection represents the network connection relationship of architecture A j under the fault combination F i .

[0105] (3) Power supply path search based on the depth-first search algorithm. In the network topology after fault injection, obtain the paths from the power supply node to each busbar node based on the depth-first search algorithm.

[0106] For all busbar nodes v ∈ V load (where V load is the set of all busbar nodes), if there is no path from the power supply node u ∈ V Source (where V Source is the set of all power supply nodes) to v, then:

[0107]

[0108] This means that architecture A i cannot supply power to this busbar node during normal and faulty conditions, so it does not meet the power supply logic constraints in the design.

[0109] For each adjacency matrix C in the set C of architectures i and each fault combination F j , through the above operations, a series of solutions C (F) that meet the power supply logic constraints can be obtained.

[0110] Step 3, namely LV3: System-level reliability calculation and weak link identification.

[0111] For the solutions C (F) that meet the fault reconstruction constraints, further calculate their basic reliability and mission reliability, and determine whether they meet the design requirements.

[0112] (1) Basic reliability mainly focuses on the durability and failure rate of the power supply system during long-term use, ensuring that the aircraft power supply system operates stably within the normal maintenance cycle and reducing unplanned downtime and maintenance costs. Basic reliability does not consider emergency switching and fault recovery during mission execution, and only evaluates the original reliability of the aircraft power supply system.

[0113] In the reliability analysis of the aircraft power supply system, reliability and failure rate are two core concepts, and there is a close mathematical relationship between them. Specifically, the failure rate λ basic(t) represents the probability of failure of the aircraft power supply system within a unit time, while the reliability R basic (t) represents the probability that the aircraft power supply system does not fail within time t. The relationship between the two is as follows:

[0114]

[0115] Among them, the failure rate λ basic (t) can be expressed as the sum of the failure rates of all components, and the corresponding calculation formula is:

[0116]

[0117] Among them, λ ij (t) is the failure rate of the branch within time t, that is, λ basic (t) is calculated as the sum of the failure rates of the components on the branch connecting node i and node j. N is the total number of components.

[0118] (2) The power supply mission reliability of the aircraft power supply system busbar mainly focuses on the real-time performance of the aircraft power supply during the flight mission, ensuring that even if some components fail, the aircraft can still successfully complete the mission and land safely.

[0119] In the aircraft power supply system, each busbar is configured with multiple power supply paths to achieve power supply redundancy. Therefore, the power supply mission reliability of the busbar needs to consider all working conditions of each busbar and comprehensively evaluate and calculate the node power supply paths.

[0120] The main steps to obtain the power supply mission reliability of the busbar are as follows:

[0121] ① Generate an equivalent network diagram and obtain the minimum paths: Generate an equivalent network diagram according to the architecture of the aircraft power supply system, and use the adjacency matrix to describe the connection relationship between components. Combining with the depth search algorithm - Depth-First Search (DFS), obtain all power supply paths path l .

[0122] ② Minimum path non-intersection and reliability calculation: Since the minimum path set obtained by the depth search algorithm usually has path intersections, that is, the same arc in the path may be repeatedly used in multiple minimum paths. Therefore, it is necessary to calculate the non-intersecting minimum path set Etemp of busbar l.

[0123] According to the minimum path non-intersection principle, the sum of the reliabilities of n parallel minimum paths can be equivalent to the probability of n mutually non-intersecting events. Therefore, when there are multiple power supply paths for busbar l, its mission reliability can be equivalent to the product sum of the reliabilities of each branch in Etemp.

[0124]

[0125] Among them, R task_l is the reliability of the busbar power supply task; l is the busbar serial number; Etemp jk is the disjoint branch formed by node j and node k; R(·) is the reliability function; R(Etemp jk ) is the reliability corresponding to the disjoint branch formed by node j and node k; Etemp is the minimal path set of the disjoint branch.

[0126] If the task reliability of the busbar fails to meet the reliability constraints of each busbar, then by identifying the weak nodes in the system and increasing the system architecture redundancy, the power grid architecture is updated and the system-level reliability calculation is performed again. The updated system architecture C″ i can be expressed as:

[0127] C″ i = C i + ΔC i .

[0128] Among them, C″ i is the updated power grid architecture; C i is the adjacency matrix; ΔC i is the new redundant path matrix corresponding to the increased structural redundancy.

[0129] When the architecture of the aircraft power supply system has reached the maximum power supply redundancy, it indicates that the failure rate of the components in the aircraft power supply system cannot meet the requirements. In this case, the failure rate of the components in the aircraft power supply system becomes the bottleneck restricting the further improvement of the system reliability. Therefore, it is necessary to adjust the component reliability based on the component reliability correction factor.

[0130]

[0131] Among them, α v is the reliability correction factor, which is usually a coefficient defined based on the failure rate of the component, environmental factors or technological improvements. Assume that the reliability of each component is R v , then the adjusted reliability of the component is

[0132] If the reliability parameters of the busbar all meet the reliability constraints in the design, then enter the LV4 calculation process.

[0133] LV4: Branch power flow distribution and weight loss optimization.

[0134] On the premise of the above constraints, to optimize the system weight and loss, it is necessary to first perform the power allocation of each branch to ensure that it can meet the power requirements of the aircraft power supply system under different working conditions. The calculation process can be divided into two parts: the calculation of the upper limit of branch power and the multi-objective optimization considering weight, loss, and reliability.

[0135] (1) Calculate based on the load power demand and the power of the fault reconstruction branch.

[0136] As can be seen from LV2, the adjacency matrix after fault injection represents the network connection relationship of architecture A j under the fault combination F i . After determining the fault reconstruction path, based on the power demand of the load nodes, the branch power allocation requirements under different faults are derived.

[0137] Let the power demand of the load node be P v . In each fault situation, P v must be transmitted through the branch V branches in the network. Since the branch power flow is superimposed from the lower-level branches to the upper-level branches, considering the superposition property of power transmission, the power flow requirements of each branch are calculated based on the path of transmitting power from the busbar node v to the power supply node.

[0138] Assume that this branch is in the path P u,v from the power supply node u to the busbar node v. Then the power flow on this branch needs to satisfy the following power transmission relationship:

[0139]

[0140] where A u,v is an element of the adjacency matrix, indicating whether the busbar node v is connected to the power supply node u. If A u,v = 1, it means that this branch participates in the power transmission between the two nodes.

[0141] According to the fault reconstruction path, the power allocation requirements of each branch under different fault situations can be solved. After considering all fault combinations, the final branch power allocation is the maximum value of the branch power that satisfies the load power supply under each fault situation to ensure that each branch can meet the load power supply requirements in the worst case.

[0142]

[0143] where is the set of fault combinations; is the power allocation of the branch under the fault combination F jPower configuration requirements of the lower node j. The final branch power configuration is the maximum branch power demand under all possible fault conditions.

[0144] (2) Multi-objective optimization considering weight, loss, and reliability.

[0145] The maximum value of the power configuration of each branch is selected as the basis for branch power design. Combining parameters such as component power density and efficiency, the overall weight and energy loss of the aircraft power supply system are calculated.

[0146] Based on the above calculations, the maximum value of the power configuration of each branch is selected as the basis for branch power design, and the rated power of each component in the branch can be obtained. The weight and loss of the aircraft power supply system mainly consider the weight and loss of components. Therefore, based on determining the rated power of each component in the aircraft power supply system and combining parameters such as component power density (kW / kg) and component efficiency, the weight and loss of components corresponding to the rated power can be calculated.

[0147] According to the different types of node j and node i, the weight W of the branch formed by node j and node i ij is expressed as:

[0148]

[0149] where, when i = j, W ij represents the weight of the equipment corresponding to node i, which may be the weight of the generator W G , fuel cell W FC , busbar load W EL or the weight of energy storage W ES . When i ≠ j, W ij represents the weight of the branch ij formed by node j and node i. If C ij = 0, the two nodes are not connected and W ij = 0. Otherwise, when neither node i nor node j is an energy storage node, if the voltages of the two nodes V i = V j , then the weight of the branch ij consists of the switch weight W Swi_ij , cable weight W Ca_ij . If the voltages of the two nodes V i ≠V j , then the weight of the branch ij consists of the converter weight W Con_ij , switch weight W Swi_ij , cable weight W Ca_ij . When there are energy storage nodes in node i and j, the weight of the branch ij consists of a charger / discharger.

[0150] On this basis, the NSGA-II multi-objective optimization algorithm is adopted to obtain the optimal architecture and power supply strategy that meet the design requirements and various constraint conditions. This optimization process not only considers the reasonable distribution of branch power, but also comprehensively weighs the dual objectives of the weight and energy consumption of the entire aircraft power supply system to improve the overall performance of the system.

[0151] The process mentioned in this application not only covers the design of the topology structure of the aircraft power supply system, but also integrates key elements such as fault mode analysis, reliability assessment, and branch power distribution. This optimized design process can optimize the system weight and loss on the basis of improving the reliability, safety, and stability of the aircraft power supply system, ensuring that the aircraft power supply system can operate stably and efficiently under various working conditions.

[0152] This application can be applied to the network topology design of aircraft power supply systems with any design requirements compared with the prior art. The influence of fault reconstruction on the power supply path is considered in the design process. By analyzing the weak nodes in the aircraft power supply system, the reliability of the aircraft power grid design results can be improved by increasing the redundancy degree of the system weak nodes during the power grid architecture optimization process. The influence of different faults and reconstructions on the branch power is considered in the design process, which in turn affects the weight, loss, and reliability of the aircraft power supply system.

[0153] Based on the same inventive concept, the embodiment of this application also provides a network architecture design and power flow optimization and distribution device considering faults and system reconstruction for implementing the network architecture design and power flow optimization and distribution method considering faults and system reconstruction involved above. The solution provided by this device to solve the problem is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the network architecture design and power flow optimization and distribution device considering faults and system reconstruction provided below can refer to the limitations on the network architecture design and power flow optimization and distribution method considering faults and system reconstruction in the above text, and will not be repeated here.

[0154] In an exemplary embodiment, a network architecture design and power flow optimization and distribution device considering faults and system reconstruction is provided, including:

[0155] A parameter data acquisition module for acquiring the parameter data of the aircraft power supply system. The parameter data includes: load power, energy type and quantity, the number of busbars in the architecture, power supply system, and the initial failure rate of each component of the aircraft power supply system.

[0156] The power grid architecture determination module is used to perform equivalent processing on each component in the aircraft power supply system based on electrical network theory according to parameter data, and search for the power grid architecture according to the constraint conditions to obtain the power grid architecture. The equivalent processing includes: regarding generators, busbars, and energy storage devices as nodes, and converters and contactors as edges, and representing the connection relationships between nodes in the form of an adjacency matrix; the constraint conditions include: network node constraints and network connection relationship constraints.

[0157] The path search module is used to consider the impact of single-point and multi-point faults on the system based on the power grid architecture, and use a depth search algorithm to perform path search according to the power supply logic constraints to obtain the power supply path. The power supply path is the path from the power source node to each busbar node.

[0158] The reliability determination module is used to determine the reliability according to the power supply path. The reliability includes: basic reliability and mission reliability; the basic reliability is the durability and failure rate of the aircraft power supply system during use; the mission reliability is the probability of successfully completing the mission and safely landing even if some components fail during the flight mission.

[0159] The optimization processing module is used to perform branch power flow distribution and weight loss optimization processing on the power grid architecture based on the reliability and the reliability constraints of each busbar, and determine the distribution plan. The distribution plan is used to improve the performance of the aircraft power supply system.

[0160] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combinations of these technical features do not conflict, they should be considered as within the scope described in this specification.

[0161] Specific examples are used in this article to elaborate on the principles and implementation methods of this application. The descriptions of the above embodiments are only used to help understand the method and its core idea of this application; at the same time, for those of ordinary skill in the art, according to the idea of this application, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be construed as a limitation to this application.

Claims

1. A network architecture design and power flow optimization allocation method considering failure and system reconstruction, characterized in that: The network architecture design and power flow optimization allocation method considering failure and system reconstruction includes: Acquiring parameter data of the aircraft power supply system; the parameter data includes: load power, energy type and quantity, number of bus bars in the architecture, power supply system, and initial failure rate of each component of the aircraft power supply system; According to the parameter data, each component in the aircraft power supply system is equivalently processed based on the electrical network theory, and the power grid architecture is searched according to the constraint conditions to obtain the power grid architecture; the equivalent processing includes: treating the generator, bus bar and energy storage device as nodes, the converter and contactor as edges, and representing the connection relationship between the nodes in the form of an adjacency matrix; the constraint conditions include: network node constraints and network connection relationship constraints; Based on the power grid architecture, considering the impact of single-point and multi-point failures on the system, a deep search algorithm is used to perform path search according to power supply logic constraints to obtain a power supply path; the power supply path is a path from a power source node to each bus node; Determine the reliability according to the power supply path; the reliability includes: basic reliability and mission reliability; the basic reliability is the durability and failure rate of the aircraft power supply system in use; the mission reliability is the probability of successfully completing the mission and landing safely even if some components fail during the flight mission; Based on the reliability and the reliability constraints of each bus bar, the power grid architecture is subjected to branch power flow distribution and weight loss optimization processing to determine a distribution scheme; the distribution scheme is used to improve the performance of the aircraft power supply system.

2. The method for network architecture design and power flow optimization allocation considering failure and system reconstruction according to claim 1 is characterized in that: Based on the power grid architecture, a deep search algorithm is used to search for a path according to the power supply logic constraints to obtain a power supply path, which specifically includes: The method of permutation and combination is adopted to determine the fault combination based on the power grid architecture; wherein the power grid architecture includes n architectures; each architecture has p faulty edges, and based on the p faulty edges, 2 p Fault combination; For any of the architectures, a fault is injected into each of the fault combinations, and in the power grid architecture after the fault injection, a path search is performed based on the power supply logic constraints based on the deep search algorithm to obtain the power supply path; wherein, let C' be the adjacency matrix after the fault injection, for all bus nodes v∈V load , if there is no power node u∈V Source If there is no path to v, it indicates that the architecture cannot provide power to the bus node in normal and fault conditions, and does not meet the power supply logic constraint; then: Among them, V load is the set of all busbar nodes; V Source is the set of all power nodes; P u,v is the path from the power source node u to the bus node v; V is the set of all nodes in the power grid architecture; C′ u,v It is the adjacency matrix element between the power node u and the bus node v after fault injection.

3. The method for network architecture design and power flow optimization allocation considering failure and system reconstruction according to claim 1 is characterized in that: The mission reliability includes: busbar power supply mission reliability; The calculation formula of the busbar power supply task reliability is: Among them, R task_l is the busbar power supply task reliability; l is the busbar number; Etemp jk is the non-intersecting branch formed by node j and node k; R(·) is the reliability function; R(Etemp jk ) is the reliability of the disjoint branch composed of node j and node k; Etemp is the minimum path set of the disjoint branch.

4. The method for network architecture design and power flow optimization allocation considering failure and system reconstruction according to claim 1 is characterized in that: Based on the reliability and the reliability constraints of each bus bar, the power flow distribution and weight loss optimization processing of the power grid architecture are performed to determine the distribution scheme, which specifically includes: Determining whether the reliability satisfies the reliability constraints of each bus bar to obtain a first determination result; If the first judgment result is no, then judging whether the power supply redundancy of the power grid architecture reaches a set threshold, and obtaining a second judgment result; If the second judgment result is yes, the reliability is adjusted based on the reliability correction coefficient, and the step of "judging whether the reliability satisfies the reliability constraints of each bus bar to obtain the first judgment result" is returned; If the second judgment result is no, updating the power grid architecture by increasing structural redundancy; If the first judgment result is yes, branch power flow distribution and weight loss optimization processing are performed on the power grid architecture to determine a distribution plan.

5. The method for network architecture design and power flow optimization allocation considering failure and system reconstruction according to claim 4 is characterized in that: The grid architecture is updated by increasing structural redundancy, using the formula: C i ”=C i +ΔC i ; Among them, C i " is the updated grid structure; C i is the adjacency matrix; ΔC i This is the newly added redundant path matrix corresponding to the increased structural redundancy.

6. The method for network architecture design and power flow optimization allocation considering failure and system reconstruction according to claim 4 is characterized in that: The reliability is adjusted based on the reliability correction factor, and the formula used is: in, is the adjusted reliability; α v is the reliability correction factor; R v For reliability.

7. The method for network architecture design and power flow optimization allocation considering failure and system reconstruction according to claim 4 is characterized in that: Perform branch power flow distribution and weight loss optimization processing on the power grid architecture to determine a distribution plan, specifically including: According to the power grid architecture, based on the power demand of the load node, determining the branch power configuration to perform branch power flow allocation; Based on the branch power configuration, weight and energy loss are determined according to the power density and efficiency to perform weight loss optimization processing.

8. The method for network architecture design and power flow optimization allocation considering failure and system reconstruction according to claim 7 is characterized in that: The calculation formula for branch power configuration is: in, is the branch power configuration; F j is the fault combination; For the fault combination F j The power configuration requirement of the next node j; is the fault combination set; P v is the power demand of the load node; v is the bus node; V load is the set of all busbar nodes; A u,v is the adjacency matrix element.

9. The power flow optimization allocation method considering failure and system reconstruction according to claim 7 is characterized in that: According to the different types of nodes j and i, the weight W of the branch formed by nodes j and i is ij The expression is: Among them, W i is the weight of the device corresponding to node i; C ij is the adjacency matrix corresponding to node i and node j; W Swi_ij is the switch weight in the branch formed by node j and node i; W Ca_ij is the cable weight in the branch formed by node j and node i; V i is the node voltage corresponding to node i; V j is the node voltage corresponding to node j; W Con_ij is the weight of the converter in the branch formed by node j and node i; N G is the number of generators; M FC is the number of fuel cells; N l is the number of bus bars.

10. A network architecture design and power flow optimization allocation device considering failure and system reconstruction, characterized in that: The network architecture design and power flow optimization allocation device considering failure and system reconstruction includes: A parameter data acquisition module, used to acquire parameter data of the aircraft power supply system; the parameter data includes: load power, energy type and quantity, number of bus bars in the architecture, power supply system, and initial failure rate of each component of the aircraft power supply system; A power grid architecture determination module is used to perform equivalent processing on each component in the aircraft power supply system based on the parameter data and the electrical network theory, and search for the power grid architecture according to the constraint conditions to obtain the power grid architecture; the equivalent processing includes: treating the generator, bus bar and energy storage device as nodes, and the converter and contactor as edges, and representing the connection relationship between the nodes in the form of an adjacency matrix; the constraint conditions include: network node constraints and network connection relationship constraints; A path search module is used to perform path search based on the power grid architecture and considering the impact of single-point and multi-point failures on the system, and to obtain a power supply path by using a deep search algorithm according to power supply logic constraints; the power supply path is a path from a power source node to each bus node; A reliability determination module is used to determine the reliability according to the power supply path; the reliability includes: basic reliability and mission reliability; the basic reliability is the durability and failure rate of the aircraft power supply system in use; the mission reliability is the probability of successfully completing the mission and landing safely even if some components fail during the flight mission; The optimization processing module is used to perform branch power flow distribution and weight loss optimization processing on the power grid architecture based on the reliability and reliability constraints of each bus bar, and determine a distribution plan; the distribution plan is used to improve the performance of the aircraft power supply system.

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