A power balance control method for a distributed electric propulsion system

Abstract

This invention discloses a power balance control method for a distributed electric propulsion system. Based on the system architecture of the distributed electric propulsion system, the power balance control method includes: when a fault occurs in the power-balanced distributed electric propulsion system causing an imbalance in the output power of the four battery packs, detecting the fault location and type; the fault location includes at least one of the following: battery pack BAT, propulsion motor M, propulsion motor controller C, and feeder fault; according to the detected fault location and type, executing power supply conversion control, and executing power balance control when the battery pack output power is unbalanced; the power balance control method is: by adjusting the feeder conversion switch at the front end of the corresponding propulsion motor controller C, realizing power dispatching between busbars to reduce or eliminate the imbalance in the output power of the battery packs. The technical solution provided by this invention achieves flexible power dispatching, significantly reducing or even eliminating the problem of unbalanced output power of the battery packs.

Description

Technical Field

[0001] This invention relates to, but is not limited to, the field of distributed electric propulsion aircraft technology, and particularly to a power balance control method for a distributed electric propulsion system. Background Technology

[0002] For a long time, due to the continuous growth in the scale of air transport, emissions of carbon oxides, nitrogen oxides, and noise from aviation have been increasing, necessitating new power methods. Electric propulsion technology can significantly reduce emissions of carbon oxides, nitrogen oxides, and noise, promoting the achievement of green and environmentally friendly development goals. Furthermore, electric propulsion technology can improve energy efficiency and enhance flight economics.

[0003] Currently, turbofan engines utilize fuel energy at an efficiency of only about 40%, while electric propulsion systems can utilize electrical energy at an efficiency exceeding 70%. This means that adopting electric propulsion technology has the potential to improve the overall system efficiency, thereby reducing fuel consumption and improving flight economy. Thanks to its "scale independence" (the power density and efficiency of the entire system remain essentially unchanged after a large-power electric motor is decomposed into several smaller-power electric motors), distributed electric propulsion systems can integrate the aircraft's power system into its aerodynamic layout, achieving optimal fusion of aerodynamics, structure, and power to reduce weight and drag, thereby improving overall aircraft efficiency.

[0004] Current research on electric propulsion aircraft mainly focuses on low-power centralized electric propulsion for general aviation. Research on distributed electric propulsion systems is still in the early theoretical and scaled-down ground test exploration stage, and the battery packs in distributed electric propulsion systems have the problem of unbalanced output power. Summary of the Invention

[0005] The purpose of this invention is to solve the above-mentioned technical problems. This invention provides a power balance control method for a distributed electric propulsion system to achieve flexible power dispatch and significantly reduce or even eliminate the problem of unbalanced output power of battery packs.

[0006] The technical solution of this invention: This embodiment of the invention provides a power balance control method for a distributed electric propulsion system. The distributed electric propulsion system includes: a left A-channel (AL) and a right A-channel (AR) symmetrically distributed on both sides of a distributed electric propulsion aircraft, and a left B-channel (BL) and a right B-channel (BR) symmetrically distributed on both sides. The A-channels are located inside the B-channels. The four channels include four busbars (BL BUS, AL BUS, AR BUS, BR BUS) and four battery packs (BL BAT, AL BAT, AR BAT, BR BUS). The system includes a busbar (BAT), four main channel contactors (BLC, ALC, ARC, BR), two transfer channel contactors (BTC1, BTC2), 4n feeder transfer switches, 4n fuses, 4n propulsion motor controllers, 4n propulsion motors, 4n circuit breakers, and 4n propellers, as well as a system control unit, where n is a positive integer greater than or equal to 1. Each channel's battery pack is connected to the busbar via one main channel contactor, supplying power to the busbar. The main channel contactors control the on / off state of the battery pack and busbar in each channel. The busbar AL BUS of the left A channel and the busbar AR BUS of the right A channel are connected via transfer channel contactor BTC1, and the busbar BL of the left B channel... The BUS and the right-side B channel busbar BRBUS are connected via a switching channel contactor BTC2, and the on / off state between the two busbars connected to it is controlled by each switching channel contactor; in the left-side A channel (AL) and left-side B channel (BL), each propulsion motor controller is selectively powered via BL BUS or AL BUS through a feeder switching switch; in the right-side A channel (AR) and right-side B channel (BR), each propulsion motor controller is selectively powered via AR BUS or BR BUS through a feeder switching switch; a fuse for overcurrent protection is connected between the propulsion motor controller and the feeder switching switch; the system control unit is connected to each battery pack, each busbar, each main channel contactor, each switching channel contactor, and each feeder switching switch respectively;

[0007] The power balance control method for the distributed electric propulsion system includes:

[0008] When a fault occurs in the power-balanced distributed electric propulsion system, causing an imbalance in the output power of the four battery packs, the location and type of the fault are detected; the fault location includes at least one of the following: battery pack BAT, propulsion motor M, propulsion motor controller C, and feeder fault;

[0009] Based on the detected fault location and type, power supply conversion control is executed, and power balance control is executed when the battery pack output power is unbalanced. The power balance control method is as follows: by adjusting the feeder conversion switch at the front end of the corresponding propulsion motor controller C, the power dispatch between the busbars is realized to reduce or eliminate the battery pack output power imbalance.

[0010] Optionally, in the power balance control method for the distributed electric propulsion system described above, the power balance control method includes:

[0011] Step 1: Obtain the status of each component in the distributed electric propulsion system, including: battery pack, contactor, feeder transfer switch, propulsion motor, propulsion motor controller, and fault status of feeder transfer switch; determine whether power supply conversion control needs to be executed based on the status of each component in the system.

[0012] Step 2: When the power supply status of each component in the system changes, complete the power supply conversion control of the system according to the power supply mode and power supply conversion method.

[0013] Step 3: Detect the output status of the available battery packs and determine whether the output power of the battery packs is balanced;

[0014] Step 4: When it is determined in Step 3 that the output power of the available battery packs is unbalanced, power balance control is executed, including: adjusting the feeder switching switch to ensure that each available battery pack supplies power to the same number of propulsion motor controllers as much as possible, thereby achieving power balance of the available battery packs; when it is determined in Step 3 that the output power of the available battery packs is balanced, power balance control is skipped, and the system waits for the status of each component to be updated before starting a new round of power supply switching control or power balance control.

[0015] Optionally, in the power balance control method of the distributed electric propulsion system described above, in the distributed electric propulsion system, battery pack BL BAT is connected to busbar BL BUS via main channel contactor BLC; battery pack AL BAT is connected to busbar AL BUS via main channel contactor ALC; battery pack AR BAT is connected to busbar AR BUS via main channel contactor ARC; and battery pack BR ​​BAT is connected to busbar BR BUS via main channel contactor BRC.

[0016] In the distributed electric propulsion system, the feeder switch S1 controls whether the propulsion motor controller C1 is powered by the BL BUS or the AL BUS; the feeder switch S7 controls whether the propulsion motor controller C7 is powered by the BL BUS or the AL BUS; the feeder switch S6 controls whether the propulsion motor controller C6 is powered by the BL BUS or the AL BUS; the feeder switch S4 controls whether the propulsion motor controller C4 is powered by the AL BUS or the BL BUS; the feeder switch S10 controls whether the propulsion motor controller C10 is powered by the AL BUS or the BL BUS; the feeder switch S5 controls whether the propulsion motor controller C5 is powered by the AL BUS or the BL BUS; the feeder switch S3 controls whether the propulsion motor controller C3 is powered by the AR BUS or the BR BUS; and the feeder switch S9 controls whether the propulsion motor controller C9 is powered by the AR BUS. The feeder switch S11 controls whether the propulsion motor controller C11 is powered by the AR bus or the BR bus; the feeder switch S2 controls whether the propulsion motor controller C2 is powered by the BR bus or the AR bus; the feeder switch S8 controls whether the propulsion motor controller C8 is powered by the BR bus or the AR bus; the feeder switch S12 controls whether the propulsion motor controller C12 is powered by the BR bus or the AR bus.

[0017] Optionally, in the power balance control method of the distributed electric propulsion system described above, the status information of the four battery packs, as well as the on / off status of the corresponding four main channel contactors and two switching channel contactors, form 16 power supply states of the distributed electric propulsion system and 64 power supply conversion modes.

[0018] The power supply logic table for the distributed electric propulsion system is as follows:

[0019]

[0020]

[0021] The 64 power supply conversion modes include bidirectional conversion of the following state transition relationships: 1) State 1 <—> State 2;

[0022] 2) State 1 <—> State 3;

[0023] 3) State 1 <—> State 4;

[0024] 4) State 1 <—> State 5;

[0025] 5) State 2 <—> State 6;

[0026] 6) State 2 <—> State 7;

[0027] 7) State 2 <—> State 8;

[0028] 8) State 3 <—> State 6;

[0029] 9) State 3 <—> State 9;

[0030] 10) State 3 <—> State 10;

[0031] 11) State 4 <—> State 7;

[0032] 12) State 4 <—> State 9;

[0033] 13) State 4 <—> State 11;

[0034] 14) State 5 <—> State 8;

[0035] 15) State 5 <—> State 10;

[0036] 16) State 5 <—> State 11;

[0037] 17) State 6 <—> State 12;

[0038] 18) State 6 <—> State 13;

[0039] 19) State 7 <—> State 12;

[0040] 20) State 7 <—> State 14;

[0041] 21) State 8 <—> State 13;

[0042] 22) State 8 <—> State 14;

[0043] 23) State 9 <—> State 12;

[0044] 24) State 9 <—> State 15;

[0045] 25) State 10 <—> State 13;

[0046] 26) State 10 <—> State 15;

[0047] 27) State 11 <—> State 14;

[0048] 28) State 11 <—> State 15;

[0049] 29) State 12 <—> State 16;

[0050] 30) State 13 <—> State 16;

[0051] 31) State 14 <—> State 16;

[0052] 32) State 15 <—> State 16.

[0053] Optionally, in the power balance control method for a distributed electric propulsion system as described above, in step 4, the power balance control of the distributed electric propulsion system is implemented using an ant colony algorithm, the design of which includes:

[0054] S1, the objective function for minimizing the cost of powering the motor with the battery pack used for power balance control in a distributed electric propulsion system is:

[0055] Cost i,j Let num represent the cost of the i-th battery pack performing the j-th task, N represent the total number of available battery packs, and num represent the cost of the i-th battery pack performing the j-th task. i This represents the number of motors powered by the i-th battery pack.

[0056] S2, determine the constraints of the objective function, including: battery pack load capacity constraints, power balance constraints, propulsion motor constraints, etc.

[0057] Optionally, in the power balance control method for a distributed electric propulsion system as described above, the constraints in step S2 are as follows:

[0058] 1) Battery pack load capacity constraint: Each available battery pack can only power a maximum of 6 propulsion motors, i.e., 1 ≤ num i ≤6;

[0059] Where, num i This represents the number of motors powered by the i-th battery pack.

[0060] 2) Power balance constraint: To ensure power balance, the difference in the number of propulsion motors corresponding to each battery pack should not exceed 1, that is:

[0061] num a -num b ≤1, a=(1,2,...,N), b=(1,2,...,N) and a≠b;

[0062] 3) Propulsion motor constraint: A propulsion motor can only be powered by one battery pack, that is: And a≠b;

[0063] Among them, task aThis represents the set of motors powered by the a-th battery pack. b This represents the set of motors powered by the b-th battery pack;

[0064] 4) Battery pack power supply capacity constraints: Based on the different states of the two switching channel contactors, the power supply capacity of each battery pack to each propulsion motor is obtained as follows:

[0065]

[0066] ability i This indicates the ability of the i-th battery pack to power 12 propulsion motors. 1 indicates that the battery pack can power the motor, and 0 indicates that it cannot power the motor. ability1, ability2, ability3, and ability4 represent the following respectively: BLBAT power supply capability, AL BAT power supply capability, AR BAT power supply capability, and BR BAT power supply capability.

[0067] 5) Power supply cost constraints for the propulsion motor:

[0068] The costs of each battery pack supplying power to each propulsion motor under different operating conditions are as follows:

[0069]

[0070] In this context, Cost1, Cost2, Cost3, and Cost4 represent, respectively: BL BAT (motor power supply cost), AL BAT (motor power supply cost), AR BAT (motor power supply cost), and BR BAT (motor power supply cost). When BTC2 = 0, it indicates that, with BTC2 disconnected, considering the battery pack's power supply capacity constraints, this represents the sequential power supply cost of the motors that the battery pack can power.

[0071] Optionally, in the power balance control method for the distributed electric propulsion system described above, the power balance control based on the designed ant colony algorithm includes the following methods:

[0072] Step 51: Collect the power supply status of each battery pack and each propulsion motor, and update the status of the battery pack and propulsion motor.

[0073] Step 52, Initialize parameters: The number of available battery packs is N, the number of available propulsion motors is M, and ant colony algorithm related parameters, such as the total number of ants is ant_num and the maximum number of iterations is NC_max; initialize the tabu list of each ant to be empty. The tabu list is used to record the propulsion motors that each ant has selected on its current path, in order to avoid ants repeating paths.

[0074] Step 53: Randomly select an unpowered available propulsion motor for ant k from M propulsion motors, calculate the transfer probability, and select a propulsion motor that can supply power to the battery pack.

[0075] Step 54: Update the taboo table and record the propulsion motors that ant k has already selected. Repeat step 3 until all ants have no propulsion motors to choose from, then end the current journey; that is, exit the loop of steps 54 and 53 and proceed to step 55.

[0076] Step 55: Determine whether the power allocation in this iteration satisfies the above constraints. If it does, calculate the objective function value of the power allocation result for each ant and record the optimal power allocation result for this iteration, that is, obtain the propulsion motor corresponding to each available battery pack, and update the pheromone. The specific pheromone update expression is shown in the following formula; otherwise, return to step 53.

[0077] Step 56: If the number of iterations NC reaches the maximum value NC_max, then output the optimal power supply result and the algorithm ends; otherwise, NC = NC + 1, and return to step three.

[0078] Optionally, in the power balance control method for the distributed electric propulsion system described above, the formula for calculating the transfer probability of an ant moving from the i-th available battery pack to the selected j-th unpowered propulsion motor in step 53 is as follows:

[0079]

[0080] Where, τ ij (t) represents the pheromone concentration value from the i-th battery pack to the j-th motor, η ij (t) is the heuristic function, which is the reciprocal of the cost of the battery pack powering the motor. α is the pheromone heuristic factor, which represents the importance of the pheromone left on the path traversed by the ant. β is the expected heuristic factor, which represents the importance of the heuristic information left by the ant when transferring nodes. allowed represents the set of unvisited nodes.

[0081] The beneficial effects of this invention: This invention provides a power balance control method for a distributed electric propulsion system. Based on the system architecture of the distributed electric propulsion system, when a fault occurs in the power-balanced distributed electric propulsion system causing an imbalance in the output power of the four battery packs, the method detects the fault location and type. The fault location includes at least one of the following: battery pack BAT, propulsion motor M, propulsion motor controller C, and feeder fault. Based on the detected fault location and type, power supply conversion control is executed, and power balance control is executed when the output power of the battery packs is unbalanced. The power balance control method involves adjusting the feeder conversion switch at the front end of the corresponding propulsion motor controller C to achieve power dispatching between the busbars, thereby reducing or eliminating the imbalance in the output power of the battery packs. In this embodiment of the invention, a feeder transfer switch is used to connect the propulsion motor controller and the busbar, and a busbar is selected for power supply through the feeder transfer switch to achieve balanced control of the output power of the battery pack. Compared with traditional power supply conversion control, the added power balance control scheme enables the electric propulsion system to achieve flexible power dispatch by adjusting the feeder transfer switches at the front end of each propulsion motor controller when battery, propulsion motor, or controller failures occur, thereby significantly reducing or even eliminating the imbalance of the battery pack output power. Attached Figure Description

[0082] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of the present invention and do not constitute a limitation on the technical solutions of the present invention.

[0083] Figure 1 This is a schematic diagram of the layout of the components in the distributed electric propulsion system on the aircraft in an embodiment of the present invention;

[0084] Figure 2 This is a schematic diagram of the system architecture of a distributed electric propulsion system used to execute the power supply conversion control method in an embodiment of the present invention;

[0085] Figure 3 This is a schematic diagram illustrating the power supply state transition relationship of the distributed electric propulsion system in an embodiment of the present invention;

[0086] Figure 4 A flowchart of a power balance control method for a distributed electric propulsion system provided in an embodiment of the present invention;

[0087] Figure 5 The flowchart of the power balance control method in the power balance control method of the distributed electric propulsion system provided in the embodiment of the present invention is shown.

[0088] Figure 6 This is a flowchart illustrating the control process from state 1 to state 2 in an embodiment of the present invention.

[0089] Figure 7 This is a flowchart illustrating the control process from state 2 to state 8 in an embodiment of the present invention.

[0090] Figure 8 This is a flowchart illustrating the control process from state 16 to state 13 in an embodiment of the present invention.

[0091] Figure 9 This is a flowchart illustrating the control process from state 13 to state 6 in an embodiment of the present invention. Detailed Implementation

[0092] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

[0093] As explained in the background section, electric propulsion technology can improve energy efficiency and flight economy, and it also demonstrates the advantages of distributed electric propulsion systems in aircraft power systems. However, current research on distributed electric propulsion systems is in the early theoretical and scaled-down ground testing stages, and the battery packs in distributed electric propulsion systems suffer from power imbalance issues.

[0094] To address the aforementioned issues, this invention provides a power balance control method for a distributed electric propulsion system. Compared to traditional power supply conversion control, this method incorporates a power balance control strategy. This allows the distributed electric propulsion system to achieve flexible power dispatch by adjusting the feeder switching switches at the front end of each propulsion motor controller when battery, propulsion motor, or controller failures occur. This significantly reduces or even eliminates the imbalance in the output power of the battery pack.

[0095] The present invention provides the following specific embodiments, which can be combined with each other. For the same or similar concepts or processes, they may not be described again in some embodiments.

[0096] Figure 1 This is a schematic diagram of the layout of the components in the distributed electric propulsion system on the aircraft in an embodiment of the present invention; Figure 2 This is a schematic diagram of the system architecture of a distributed electric propulsion system used to execute a power supply conversion control method in an embodiment of the present invention. (Combined with...) Figure 1 and Figure 2As shown, the distributed electric propulsion system in this embodiment of the invention includes: two A channels (including the left A channel AL and the right A channel AR) and two B channels (including the left B channel BL and the right B channel BR) symmetrically distributed on both sides of the distributed electric propulsion aircraft. The A channels are located inside the B channels, that is, the system has 4 channels, and these 4 channels include 4 busbars (BL BUS, AL BUS, AR BUS, BR BUS), 4 battery packs (BL BAT, AL BAT, AR BAT, BR BAT), 4 main channel contactors (BLC, ALC, ARC, BR), 2 switching channel contactors (BTC1, BTC2), 4n feeder changeover switches, 4n fuses, 4n propulsion motor controllers, 4n propulsion motors, 4n propellers, and a system control unit, where n is a positive integer greater than or equal to 1.

[0097] like Figure 1 and Figure 2 The names of the channels and devices in the distributed electric propulsion system of this invention, as shown in the diagram, are defined as follows:

[0098] 1) Channels: The two A channels include: the left A channel (i.e., channel AL) and the right A channel (i.e., channel AR), and the two B channels include: the left B channel (i.e., channel BL) and the right B channel (i.e., channel BR); wherein, the two B channels are outside the two A channels;

[0099] 2) Busbars: The four busbars include: BL BUS, AL BUS, AR BUS, and BR BUS;

[0100] 3) Battery packs: The four battery packs include: battery pack BL BAT, battery pack AL BAT, battery pack ARBAT, and battery pack BR ​​BAT.

[0101] 4) Main channel contactors: The four main channel contactors include: main channel contactor BLC, main channel contactor ALC, main channel contactor ARC, and main channel contactor BRC.

[0102] 5) Transfer Channel Contactors: The two transfer channel contactors are defined as follows: AL BUS and AR BUS are connected through transfer channel contactor BTC1, and BL BUS and BR BUS are connected through transfer channel contactor BTC2.

[0103] 6) Feeder selector switches: 12 feeder selector switches including: feeder selector switch S1, feeder selector switch S2, feeder selector switch S3, feeder selector switch S4, feeder selector switch S5, feeder selector switch S6, feeder selector switch S7, feeder selector switch S8, feeder selector switch S9, feeder selector switch S10, feeder selector switch S11, and feeder selector switch S12;

[0104] 7) Fuses: The 12 fuses include: fuse F1, fuse F2, fuse F3, fuse F4, fuse F5, fuse F6, fuse F7, fuse F8, fuse F9, fuse F10, fuse F11, and fuse F12; In this specific implementation, each busbar is connected to 3 fuses, and each of the 3 fuses is connected to 3 propulsion motor controllers;

[0105] 8) Propulsion motor controllers: 12 propulsion motor controllers including: propulsion motor controller C1, propulsion motor controller C2, propulsion motor controller C3, propulsion motor controller C4, propulsion motor controller C5, propulsion motor controller C6, propulsion motor controller C7, propulsion motor controller C8, propulsion motor controller C9, propulsion motor controller C10, propulsion motor controller C11, and propulsion motor controller C12;

[0106] 9) Propulsion motors: 12 propulsion motors including: propulsion motor M1, propulsion motor M2, propulsion motor M3, propulsion motor M4, propulsion motor M5, propulsion motor M6, propulsion motor M7, propulsion motor M8, propulsion motor M9, propulsion motor M10, propulsion motor M11, and propulsion motor M12;

[0107] 10) Propellers: The 12 propellers include: propeller P1, propeller P2, propeller P3, propeller P4, propeller P5, propeller P6, propeller P7, propeller P8, propeller P9, propeller P10, propeller P11, and propeller P12.

[0108] 10) System control unit: The system control unit is connected to each contactor, each feeder changeover switch, each fuse and propulsion motor controller respectively.

[0109] In an embodiment of the present invention, the specific connection structure inside the distributed electric propulsion system is as follows:

[0110] 1) Connection relationship between battery pack and busbar:

[0111] Battery pack BL BAT is connected to busbar BL BUS via main channel contactor BLC; battery pack AL BAT is connected to busbar AL BUS via main channel contactor ALC; battery pack AR BAT is connected to busbar AR BUS via main channel contactor ARC; battery pack BR ​​BAT is connected to busbar BR BUS via main channel contactor BRC; and so on. Figure 1 and Figure 2 As shown.

[0112] 2) Connection relationships between each busbar:

[0113] Busbar AL BUSS is connected to busbar AR BUS via switch channel contactor BTC1; busbar BL BUS is connected to busbar BR BUS via switch channel contactor BTC2; as shown Figure 2 As shown.

[0114] 3) The connection relationship between the feeder changeover switch, fuse, and propulsion motor controller;

[0115] Each propulsion motor controller Ci is connected to the corresponding feeder changeover switch Si via a corresponding fuse Fi, i = 1~12; in the left A channel (AL) and left B channel (BL), feeder changeover switches S1, S7, S6, S4, S10, and S5 are connected to BLBUS and AL BUS respectively; in the right A channel (AR) and right B channel (BR), feeder changeover switches S3, S9, S11, S2, S8, and S12 are connected to BR BUS and AR BUS respectively. Based on the above connection relationship, the working principle of the feeder changeover switches and fuses is as follows:

[0116] Feeder switch S1 controls whether propulsion motor controller C1 is powered by busbar BL BUS or busbar ALBUS, with fuse F1 used for overcurrent protection; feeder switch S7 controls whether propulsion motor controller C7 is powered by busbar BL BUS or busbar ALBUS, with fuse F7 used for overcurrent protection; feeder switch S6 controls whether propulsion motor controller C6 is powered by busbar BL BUS or busbar ALBUS, with fuse F6 used for overcurrent protection; feeder switch S4 controls whether propulsion motor controller C4 is powered by busbar ALBUS or busbar BL BUS, with fuse F4 used for overcurrent protection; feeder switch S10 controls whether propulsion motor controller C10 is powered by busbar ALBUS or busbar BL BUS, with fuse F10 used for overcurrent protection; feeder switch S5 controls whether propulsion motor controller C5 is powered by busbar ALBUS or busbar BL BUS. Powered by the bus, fuse F5 is used for overcurrent protection; feeder changeover switch S3 controls whether propulsion motor controller C3 is powered by busbar AR BUS or busbar BR BUS, fuse F3 is used for overcurrent protection; feeder changeover switch S9 controls whether propulsion motor controller C9 is powered by busbar AR BUS or busbar BR BUS, fuse F9 is used for overcurrent protection; feeder changeover switch S11 controls whether propulsion motor controller C11 is powered by busbar AR BUS or busbar BR BUS, fuse F11 is used for overcurrent protection; feeder changeover switch S2 controls whether propulsion motor controller C2 is powered by busbar BR BUS or busbar AR BUS, fuse F2 is used for overcurrent protection; feeder changeover switch S8 controls whether propulsion motor controller C8 is powered by busbar BR BUS or busbar AR BUS, fuse F8 is used for overcurrent protection; feeder changeover switch S12 controls whether propulsion motor controller C12 is powered by busbar BR BUS or busbar AR BUS. BUS power supply, fuse F12 is used for overcurrent protection. For example... Figure 2 As shown.

[0117] 4) The power supply principle of each busbar to each propulsion motor controller in each propulsion system is as follows:

[0118] Propulsion motor controller C1 converts the high-voltage DC power supplied by the busbar into three-phase AC power to power propulsion motor M1; propulsion motor controller C6 converts the high-voltage DC power supplied by the busbar into three-phase AC power to power propulsion motor M6; propulsion motor controller C7 converts the high-voltage DC power supplied by the busbar into three-phase AC power to power propulsion motor M7; propulsion motor controller C4 converts the high-voltage DC power supplied by the busbar into three-phase AC power to power propulsion motor M4; propulsion motor controller C5 converts the high-voltage DC power supplied by the busbar into three-phase AC power to power propulsion motor M5; propulsion motor controller C10 converts the high-voltage DC power supplied by the busbar into three-phase AC power to power propulsion motor M10; Propulsion motor controller C3 converts the high-voltage DC power supplied by the busbar into three-phase AC power to power propulsion motor M3; propulsion motor controller C9 converts the high-voltage DC power supplied by the busbar into three-phase AC power to power propulsion motor M9; propulsion motor controller C11 converts the high-voltage DC power supplied by the busbar into three-phase AC power to power propulsion motor M11; propulsion motor controller C2 converts the high-voltage DC power supplied by the busbar into three-phase AC power to power propulsion motor M2; propulsion motor controller C8 converts the high-voltage DC power supplied by the busbar into three-phase AC power to power propulsion motor M8; propulsion motor controller C12 converts the high-voltage DC power supplied by the busbar into three-phase AC power to power propulsion motor M12. For example... Figure 2 As shown

[0119] 5) The mechanical and driving relationships between the propulsion motor and the propeller in each propulsion system:

[0120] Propulsion motor M1 generates thrust through mechanical connection to propeller P1; propeller motor M6 generates thrust through mechanical connection to propeller P6; propeller motor M7 generates thrust through mechanical connection to propeller P7; propeller motor M4 generates thrust through mechanical connection to propeller P5; propeller motor M10 generates thrust through mechanical connection to propeller P10; propeller motor M3 generates thrust through mechanical connection to propeller P3; propeller motor M9 generates thrust through mechanical connection to propeller P9; propeller motor M11 generates thrust through mechanical connection to propeller P11; propeller motor M2 generates thrust through mechanical connection to propeller P2; propeller motor M8 generates thrust through mechanical connection to propeller P8; propeller motor M12 generates thrust through mechanical connection to propeller P12. For example... Figure 2 As shown.

[0121] It should be noted that the redundancy design of the distributed electric propulsion system in this embodiment of the invention is required to meet system safety requirements, specifically including the following requirements:

[0122] 1) A single battery pack has the capability to output 50% of the system's required power, meaning that any two battery packs can meet the system's maximum power requirement when operating normally.

[0123] 2) The amount of electricity stored in the four battery packs is enough to meet the power requirements of the aircraft for two flights, that is, the amount of electricity stored in any two battery packs is enough to meet the power requirements of the aircraft for a single flight.

[0124] 3) The ability of a single propulsion motor to output 10% of the system's required power when operating at its rated state, meaning that any 10 propulsion motors operating normally can meet the flight power requirements;

[0125] 4) It has the function of switching power supply according to the status of the battery pack.

[0126] The power supply logic of the distributed electric propulsion system is shown in Table 1 below:

[0127] Table 1 Power Supply Logic Table for Distributed Electric Propulsion System

[0128]

[0129]

[0130] As shown in Power Supply Logic Table 1 above, the distributed electric propulsion system in this specific implementation scheme has 16 power supply states and 64 power supply conversion modes, such as... Figure 3 The diagram shown is a schematic representation of the power supply state transition relationship of a distributed electric propulsion system in an embodiment of the present invention.

[0131] 1) State 1 <—> State 2;

[0132] 2) State 1 <—> State 3;

[0133] 3) State 1 <—> State 4;

[0134] 4) State 1 <—> State 5;

[0135] 5) State 2 <—> State 6;

[0136] 6) State 2 <—> State 7;

[0137] 7) State 2 <—> State 8;

[0138] 8) State 3 <—> State 6;

[0139] 9) State 3 <—> State 9;

[0140] 10) State 3 <—> State 10;

[0141] 11) State 4 <—> State 7;

[0142] 12) State 4 <—> State 9;

[0143] 13) State 4 <—> State 11;

[0144] 14) State 5 <—> State 8;

[0145] 15) State 5 <—> State 10;

[0146] 16) State 5 <—> State 11;

[0147] 17) State 6 <—> State 12;

[0148] 18) State 6 <—> State 13;

[0149] 19) State 7 <—> State 12;

[0150] 20) State 7 <—> State 14;

[0151] 21) State 8 <—> State 13;

[0152] 22) State 8 <—> State 14;

[0153] 23) State 9 <—> State 12;

[0154] 24) State 9 <—> State 15;

[0155] 25) State 10 <—> State 13;

[0156] 26) State 10 <—> State 15;

[0157] 27) State 11 <—> State 14;

[0158] 28) State 11 <—> State 15;

[0159] 29) State 12 <—> State 16;

[0160] 30) State 13 <—> State 16;

[0161] 31) State 14 <—> State 16;

[0162] 32) State 15 <—> State 16.

[0163] for Figure 1 and Figure 2 The distributed electric propulsion system shown may experience an imbalance in the output power of the battery pack when the battery pack (BAT), propulsion motor (M), propulsion motor controller (C), and feeder fail. By adjusting the feeder switching switches at the front end of each propulsion motor controller (C), flexible power dispatch can be achieved, significantly reducing or even eliminating the imbalance in the output power of the battery pack.

[0164] The power balance control method for a distributed electric propulsion system provided in this embodiment of the invention includes:

[0165] When a fault occurs in the power-balanced distributed electric propulsion system, causing an imbalance in the output power of the four battery packs, the location and type of the fault are detected; the fault location includes at least one of the following: battery pack BAT, propulsion motor M, propulsion motor controller C, and feeder fault;

[0166] Based on the detected fault location and type, power supply conversion control is executed, and power balance control is executed when the battery pack output power is unbalanced. The power balance control method is as follows: by adjusting the feeder conversion switch at the front end of the corresponding propulsion motor controller C, the power dispatch between the busbars is realized to reduce or eliminate the battery pack output power imbalance.

[0167] In this embodiment of the invention, it should be noted that the function of the switching channel contactors BTC1 and BTC2 is power supply switching control; the main function of the feeder switching switches S1 to S12 is battery pack power balance control, while also taking into account power supply switching control (such as in the switching control of power supply modes 8 and 9).

[0168] Figure 4 A flowchart illustrating a power balance control method for a distributed electric propulsion system provided in an embodiment of the present invention. Figure 4 As shown in the figure, the power balance control method for a distributed electric propulsion system provided in this embodiment of the invention specifically includes the following steps:

[0169] Step 1: Obtain the status of each component in the distributed electric propulsion system, including: battery pack, contactor, feeder transfer switch, propulsion motor, propulsion motor controller, and fault status of feeder transfer switch; determine whether power supply switching control needs to be executed based on the status of each component in the system.

[0170] Step 2: When the power supply status of each component in the system changes, the power supply conversion control of the system is completed according to the power supply mode (1~16) and power supply conversion form; that is, the conversion form in 32*2 above.

[0171] Step 3: Check the output status of the available battery packs to determine whether the output power of the battery packs is balanced;

[0172] Step 4: When the output power of the available battery packs is unbalanced, power balancing control is performed, including: adjusting the feeder switching switch to ensure that each available battery pack supplies power to the same number of propulsion motor controllers as much as possible, thereby achieving power balance of the available battery packs; when the output power of the available battery packs is balanced, power balancing control is skipped, and the system waits for the status of each component to be updated before performing a new round of power supply switching control or power balancing control.

[0173] In one implementation of this invention, a method for power balance control based on an ant colony algorithm is provided.

[0174] The objective function for designing a battery pack for power balance control in a distributed electric propulsion system that minimizes the cost of powering the motor is:

[0175] The above formula is used to calculate for all available battery packs, and the number of motors powered by each battery pack may be different.

[0176] Cost i,j Let num represent the cost of the i-th battery pack performing the j-th task, N represent the total number of available battery packs, and num represent the cost of the i-th battery pack performing the j-th task. i This represents the number of motors powered by the i-th battery pack.

[0177] Design the constraints for the above objective function, including:

[0178] 1) Battery pack load capacity constraint: Each available battery pack can only power a maximum of 6 propulsion motors.

[0179] 1≤num i ≤6;

[0180] Where, num i This represents the number of motors powered by the i-th battery pack.

[0181] 2) Power balance constraint: To ensure power balance, the difference in the number of propulsion motors corresponding to each battery pack should not exceed 1, that is:

[0182] num a -num b ≤1, a=(1,2,...,N), b=(1,2,...,N) and a≠b;

[0183] 3) Propulsion motor constraint: A propulsion motor can only be powered by one battery pack, that is:

[0184] And a≠b;

[0185] Among them, task a This represents the set of motors powered by the a-th battery pack. b This represents the set of motors powered by the b-th battery pack.

[0186] 4) Battery pack power supply capacity constraints: Depending on the state of the switching channel contactors (BTC1 and BTC2), the number of propulsion motors that the battery pack can power varies. The specific power supply capacity is as follows:

[0187]

[0188] ability i This indicates the ability of the i-th battery pack to power 12 propulsion motors. 1 indicates that the battery pack can power the motor, and 0 indicates that it cannot power the motor. ability1, ability2, ability3, and ability4 represent the following respectively: BLBAT power supply capability, AL BAT power supply capability, AR BAT power supply capability, and BR BAT power supply capability.

[0189] 5) Power supply cost constraints for the propulsion motor:

[0190] The costs of each battery pack supplying power to each propulsion motor under different operating conditions are as follows:

[0191]

[0192] In this context, Cost1, Cost2, Cost3, and Cost4 represent, respectively: BL BAT (motor power supply cost), AL BAT (motor power supply cost), AR BAT (motor power supply cost), and BR BAT (motor power supply cost). When BTC2 = 0, it indicates that, with BTC2 disconnected, considering the battery pack's power supply capacity constraints, this represents the sequential power supply cost of the motors that the battery pack can power.

[0193] like Figure 5 The diagram shown is an algorithm flowchart for the power balance control method in the power balance control method of the distributed electric propulsion system provided in this embodiment of the invention. The power balance control method based on the ant colony algorithm includes the following steps:

[0194] Step 1: Collect the power supply status of each battery pack and each propulsion motor, and update the status of the battery pack and propulsion motor; the status in this step refers to the switching between 0 and 1.

[0195] Step 2: Initialize parameters: The number of available battery banks is N, the number of available propulsion motors is M, and ant colony algorithm parameters are set, such as the total number of ants (ant_num) and the maximum number of iterations (NC_max). Initialize the tabu list for each ant to be empty. The tabu list records the propulsion motors that each ant has already selected on its current path, preventing ants from repeating paths.

[0196] It should be noted that in the ant colony algorithm, each ant seeks the path with the minimum cost, and an empty value indicates that the path has not been sought.

[0197] Step 3: Randomly select an available, unpowered propulsion motor for ant k (from M propulsion motors), calculate the transfer probability, and select a propulsion motor that can supply power to the battery pack. The formula for calculating the transfer probability of the ant moving from the i-th available battery pack to the selected unpowered j-th propulsion motor is as follows:

[0198]

[0199] Where, τ ij (t) represents the pheromone concentration value from the i-th battery pack to the j-th motor, η ij (t) is the heuristic function, which is the reciprocal of the cost of the battery pack powering the motor. α is the pheromone heuristic factor, which represents the importance of the pheromone left on the path traversed by the ant. β is the expected heuristic factor, which represents the importance of the heuristic information left by the ant when transferring nodes. allowed represents the set of unvisited nodes.

[0200] Step 4: Update the taboo table and record the propulsion motors that ant k has already selected. Repeat step 3 until all ants have no propulsion motors to choose from, then end the current journey; that is, exit the loop from step 4 to 3 and proceed to step 5.

[0201] Step 5: Determine whether the power allocation satisfies the above constraints. If it does, calculate the objective function value of the power allocation for each ant and record the optimal power supply result for this iteration, i.e., obtain the propulsion motor corresponding to each available battery pack, and update the pheromone. The specific pheromone update expression is shown in the formula below; otherwise, return to Step 3. It should be noted that "optimal" means that the superimposed cost value of all available battery packs is minimized.

[0202] τ ij (t+1)=(1-ρ)τ ij (t)+Δτ ijk (t+1);

[0203]

[0204] Where, Δτ ijk (t) represents the amount of pheromone left on the path by the k-th ant in this iteration; Q is the pheromone intensity, which affects the convergence speed of the algorithm to some extent; L k This represents the search length of the k-th ant in this iteration.

[0205] Step 6: If the number of iterations NC reaches the maximum value NC_max, then output the optimal power supply result and the algorithm ends; otherwise, NC = NC + 1, and return to step 3.

[0206] The power balance control method for a distributed electric propulsion system provided in this invention is based on the system architecture of the distributed electric propulsion system. When a fault occurs in the power-balanced distributed electric propulsion system, causing an imbalance in the output power of the four battery packs, the fault location and type are detected. The fault location includes at least one of the following: battery pack BAT, propulsion motor M, propulsion motor controller C, and feeder fault. Based on the detected fault location and type, power supply conversion control is executed, and power balance control is executed when the output power of the battery packs is unbalanced. The power balance control method is as follows: by adjusting the feeder conversion switch at the front end of the corresponding propulsion motor controller C, power scheduling between the busbars is realized to reduce or eliminate the imbalance in the output power of the battery packs. In this embodiment of the invention, a feeder transfer switch is used to connect the propulsion motor controller and the busbar, and a busbar is selected for power supply through the feeder transfer switch to achieve balanced control of the output power of the battery pack. Compared with traditional power supply conversion control, the added power balance control scheme enables the electric propulsion system to achieve flexible power dispatch by adjusting the feeder transfer switches at the front end of each propulsion motor controller when battery, propulsion motor, or controller failures occur, thereby significantly reducing or even eliminating the imbalance of the battery pack output power.

[0207] The following example illustrates the implementation of the power balance control method for a distributed electric propulsion system provided by this invention:

[0208] Implementation example;

[0209] The power balance control method for a distributed electric propulsion system provided in this implementation example is as follows:

[0210] A schematic diagram of the layout of various components on the aircraft is shown below. Figure 1 As shown.

[0211] Figure 2 This is a single-line diagram of the high-voltage direct current electric propulsion system architecture for this distributed electric propulsion aircraft. The battery packs BL BAT, AL BAT, AR BAT, and BR BAT have voltages ranging from 450 to 660V, and each propulsion motor has a rated power of 15kW.

[0212] The distributed electric propulsion system provided by this invention has 16 power supply states, and there are 64 power supply conversion modes between these 16 power supply states, such as... Figure 3 The diagram shows the power supply conversion of the high-voltage direct current electric propulsion system of this distributed electric propulsion aircraft.

[0213] The 16 power supply modes mentioned above can be divided into 5 categories:

[0214] Category 1: Powered by 4 battery packs, serial number 16;

[0215] Category 2: Powered by 3 battery packs, numbered 12, 13, 14, and 15;

[0216] Category 3: Powered by 2 battery packs: serial numbers 6, 7, 8, 9, 10, and 11; serial numbers 6, 7, 10, and 11 have similar control methods and can be grouped into one group; serial numbers 8 and 9 have similar control methods and can be grouped into one group.

[0217] Category 4: Powered by one battery pack: serial numbers 2, 3, 4, and 5;

[0218] Category 5: Powered by 0 battery packs: Serial number 1.

[0219] The following example illustrates the power supply conversion control process:

[0220] (1) The system power supply conversion control process from serial number 1 to serial number 2 is as follows: Figure 6 As shown. First, contactors BTC1 and BTC2 are initialized to the open state. Then, it is determined whether BR BAT is available. If it is not available, the system returns to power supply state 1 and waits for system status updates; if it is available, BRC is closed. If BR BUS is de-energized within a given delay time, a fault is marked according to the status of the BRC auxiliary contacts, and the system returns to power supply state 1; if BR BUS is energized within a given delay time, BTC2 is closed. If BL BUS is energized within a given delay time, the power supply transition is complete, and power supply state 2 is locked; if BL BUS is de-energized within a given delay time, a fault is marked according to the status of the BTC2 auxiliary contacts, the power supply transition is complete, and power supply state 2 is locked.

[0221] (2) The system power supply conversion control process from serial number 2 to serial number 8 is as follows: Figure 7 As shown. First, contactor BTC2 is disconnected. If BTC2 fails to disconnect within a given delay time, a fault is marked for BTC2 failure to disconnect, and the system returns to power supply state 2. If BTC2 disconnects normally within the given delay time, feeder changeover switches S3, S9, and S11 are powered by the BR BUS, and the BLC is closed. On one hand, after a fixed delay, a fault is marked for the feeder changeover switches based on the power supply status of the propulsion motor controllers C3, C9, and C11. On the other hand, if the BL BUS is de-energized within the given delay time, a fault is marked based on the status of the BLC auxiliary contacts, and the system returns to power supply state 2. If the BL BUS is energized within the given delay time, feeder changeover switches S4, S5, and S10 are powered by the BL BUS. After a fixed delay, a fault is marked for the feeder changeover switches based on the power supply status of the propulsion motor controllers C4, C5, and C10. At this point, the power supply conversion is complete, and power supply state 6 is locked.

[0222] (3) The system power supply conversion control process from serial number 16 to serial number 13 is as follows: Figure 8As shown. First, contactor ALC is disconnected. If ALC fails to disconnect within a given delay time, an ALC disconnection failure fault is marked, and the system returns to state 16 and locks the state. If ALC disconnects within the given delay time, contactor BTC1 is closed. If AL BUS is energized within the given delay time, the power supply conversion is complete, and power supply state 13 is locked. If AL BUS is de-energized within the given delay time, a fault is marked according to the auxiliary contact status of BTC1. Then, feeder transfer switches S4, S5, and S10 are controlled to be powered by BL BUS. After a fixed delay, the feeder transfer switch fault status is marked according to the power supply status of propulsion motor controllers C4, C5, and C10. At this point, the power supply conversion is complete, and power supply state 13 is locked.

[0223] (4) The system power supply conversion control process from serial number 13 to serial number 6 is as follows: Figure 9 As shown. First, disconnect contactor BLC. If BL BUS is still energized beyond the given delay time, a fault is marked indicating that BLC cannot be disconnected, and the system returns to power supply state 13 and locks the state; if BL BUS is de-energized within the given delay time, contactor BTC2 is closed. If BTC2 closes within the given time, the power supply conversion is complete, and power supply state 6 is locked; if BTC2 fails to close beyond the given delay time, a fault is marked according to the status of the auxiliary contact of BTC2, the power supply conversion is complete, and power supply state 6 is locked.

[0224] The following example illustrates the power balance control method in this implementation example:

[0225] (1) Power supply status of sequence number 16: At this time, all battery banks are available, and contactors BTC1 and BTC2 are disconnected. Assume the system status at this time is as shown in the table below:

[0226]

[0227] According to the system power supply logic, the system power supply status at this time is as follows: BL BAT supplies power to C1 through BL BUS; AL BAT supplies power to C4, C5 and C10 through AL BUS; AR BAT supplies power to C3, C9 and C11 through AR BUS; BR BAT supplies power to C2, C8 and C12 through BR BUS.

[0228] The power balance control method provided by this invention has the following control process:

[0229] Control the feeder changeover switch S4 to power C4 via BL BUS;

[0230] Control other feeder changeover switches in their default states (control feeder changeover switch S1 to power C1 via BL BUS; control feeder changeover switches S5 and S10 to power C5 and C10 via AL BUS; control feeder changeover switches S3, S9, and S11 to power C3, C9, and C11 via AR BUS; control feeder changeover switches S2, S8, and S12 to power C2, C8, and C12 via BR BUS).

[0231] Ultimately, the system power supply status is as follows: BL BAT supplies power to C1 and C4 via BL BUS; AL BAT supplies power to C5 and C10 via AL BUS; AR BAT supplies power to C3, C9, and C11 via AR BUS; and BR BAT supplies power to C2, C8, and C12 via BR BUS. The output power of batteries BL BAT and AL BAT is balanced. The output power of batteries AR BAT and BR BAT is also balanced.

[0232] (2) Power supply status 13: AL BAT is unavailable, contactor BTC1 is closed, and AL BUS is powered by AR BAT. Assume the system status at this time is as shown in the table below:

[0233]

[0234] According to the system power supply logic, the system power supply status at this time is as follows: BL BAT supplies power to C1, C6 and C7 through BL BUS; AR BAT supplies power to C3, C9 and C11 through AR BUS, and AR BAT supplies power to AL BUS and C4, C5 and C10 through BTC1; BR BAT supplies power to C2, C8 and C12 through BR BUS.

[0235] The power balance control method provided by this invention has the following control process:

[0236] Control the feeder changeover switch S4 to power C4 via BL BUS;

[0237] Control the feeder changeover switch S11 to power C11 from the BR BUS.

[0238] Control other feeder changeover switches in their default state (control feeder changeover switches S5 and S10 so that C5 and C10 are powered by AL BUS; control feeder changeover switches S3 and S9 so that C3 and C9 are powered by AR BUS).

[0239] Ultimately, the system power supply status is as follows: BL BAT supplies power to C1, C4, C6, and C7 via BL BUS; AR BAT supplies power to C3 and C9 via ARBUS, and simultaneously supplies power to C5 and C10 via AL BUS; BR BAT supplies power to C2, C8, C11, and C12 via BR BUS. The output power of batteries BL BAT, AR BAT, and BR BAT is balanced.

[0240] (3) In power supply state 8, AL BAT and AR BAT are unavailable, contactors BTC1 and BTC2 are both open, and feeder transfer switches S4, S5, and S10 control C4, C5, and C10 to be powered by BL BUS, while feeder transfer switches S3, S9, and S11 control C3, C9, and C11 to be powered by BR BUS. At this time, the left and right channels form two independent power supply channels, making it impossible to mutually dispatch power, and the conditions for carrying out power balance control are not met. Similarly, power supply state 9 does not meet the conditions for carrying out power balance control.

[0241] (4) Power supply status of serial number 6: BL BAT and AL BAT are unavailable, contactors BTC1 and BTC2 are both closed, AR BAT supplies power to AL BUS, and BR BAT supplies power to BL BUS. Assume the system status at this time is as shown in the table below:

[0242]

[0243] According to the system power supply logic, the system power supply status at this time is as follows: BR BAT supplies power to C2, C8 and C12 through BR BUS, and BR BAT supplies power to BL BUS and C1 through BTC2; AR BAT supplies power to C3, C9 and C11 through AR BUS, and ARBAT supplies power to AL BUS and C4, C5 and C10 through BTC1.

[0244] The power balance control method provided by this invention has the following control process:

[0245] Control the feeder changeover switch S4 to power C4 via BL BUS;

[0246] Control other feeder changeover switches in their default states (control feeder changeover switch S1 to power C1 via BL BUS; control feeder changeover switches S5 and S10 to power C5 and C10 via AL BUS; control feeder changeover switches S3, S9, and S11 to power C3, C9, and C11 via AR BUS; control feeder changeover switches S2, S8, and S12 to power C2, C8, and C12 via BR BUS).

[0247] The BR BAT supplies power to C2, C8, and C12 via the BR BUS, while supplying power to C1 and C4 via the BL BUS; the ARBAT supplies power to C3, C9, and C11 via the AR BUS, while supplying power to C5 and C10 via the AL BUS. The output power of the battery AR BAT and BR BAT is balanced.

[0248] While the embodiments disclosed in this invention are as described above, they are merely illustrative of the embodiments to facilitate understanding of the invention and are not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and variations in the form and details of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection for this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A power balance control method for a distributed electric propulsion system, characterized in that, The distributed electric propulsion system includes: a left A-channel AL and a right A-channel AR symmetrically distributed on both sides of the distributed electric propulsion aircraft, and a left B-channel BL and a right B-channel BR symmetrically distributed on both sides. The A-channels are located inside the B-channels. Each of the four channels includes four busbars BL BUS, ALBUS, AR BUS, and BR BUS; four battery packs BL BAT, AL BAT, AR BAT, and BR BAT; four main channel contactors BLC, ALC, ARC, and BRC; two transfer channel contactors BTC1 and BTC2; 4n feeder transfer switches; 4n fuses; 4n propulsion motor controllers; 4n propulsion motors; 4n circuit breakers; and 4n propellers; as well as a system control unit, where n is a positive integer greater than or equal to 1. Each battery pack in each channel is connected to the busbars via one main channel contactor, supplying power to the busbars through the battery packs. The main channel contactors control the on / off state of the battery packs and busbars in each channel. The left A-channel busbar AL... The BUS and the right A channel busbar AR BUS are connected via a switching channel contactor BTC1. The left B channel busbar BL BUS and the right B channel busbar BR BUS are connected via a switching channel contactor BTC2. Each switching channel contactor controls the on / off state between the two busbars connected to it. In the left A channel AL and the left B channel BL, each propulsion motor controller is selectively powered via BL BUS or AL BUS through a feeder switching switch. In the right A channel AR and the right B channel BR, each propulsion motor controller is selectively powered via ARBUS or BR BUS through a feeder switching switch. A fuse for overcurrent protection is connected between the propulsion motor controller and the feeder switching switch. The system control unit is connected to each battery pack, each busbar, each main channel contactor, each switching channel contactor, and each feeder switching switch. The power balance control method for the distributed electric propulsion system includes: When a fault occurs in the power-balanced distributed electric propulsion system, causing an imbalance in the output power of the four battery packs, the location and type of the fault are detected; the fault location includes at least one of the following: battery pack, propulsion motor, propulsion motor controller, and feeder fault; Based on the detected fault location and type, power supply conversion control is executed, and power balancing control is executed when the output power of the battery pack is unbalanced. The power balancing control method is as follows: by adjusting the feeder conversion switch at the front end of the corresponding propulsion motor controller, the power dispatch between the busbars is realized to reduce or eliminate the imbalance of the output power of the battery pack. The power balance control method includes: Step 1: Obtain the status of each component in the distributed electric propulsion system, including: battery pack, contactor, feeder transfer switch, propulsion motor, propulsion motor controller, and fault status of feeder transfer switch; determine whether power supply conversion control needs to be executed based on the status of each component in the system. Step 2: When the power supply status of each component in the system changes, complete the power supply conversion control of the system according to the power supply mode and power supply conversion method. Step 3: Detect the output status of the available battery packs and determine whether the output power of the battery packs is balanced; Step 4: When it is determined in Step 3 that the output power of the available battery packs is unbalanced, power balance control is executed, including: adjusting the feeder switching switch to ensure that each available battery pack supplies power to the same number of propulsion motor controllers as much as possible, thereby achieving power balance of the available battery packs; when it is determined in Step 3 that the output power of the available battery packs is balanced, power balance control is skipped, and the system waits for the status of each component to be updated before starting a new round of power supply switching control or power balance control.

2. The power balance control method for a distributed electric propulsion system according to claim 1, characterized in that, In the distributed electric propulsion system, battery pack BL BAT is connected to busbar BL BUS via main channel contactor BLC; battery pack AL BAT is connected to busbar AL BUS via main channel contactor ALC; battery pack AR BAT is connected to busbar AR BUS via main channel contactor ARC; and battery pack BR ​​BAT is connected to busbar BR BUS via main channel contactor BRC. In the distributed electric propulsion system, the feeder switch S1 controls whether the propulsion motor controller C1 is powered by the BLBUS or the ALBUS busbar; the feeder switch S7 controls whether the propulsion motor controller C7 is powered by the BLBUS or the ALBUS busbar; the feeder switch S6 controls whether the propulsion motor controller C6 is powered by the BLBUS or the ALBUS busbar; the feeder switch S4 controls whether the propulsion motor controller C4 is powered by the ALBUS or the BLBUS busbar; the feeder switch S10 controls whether the propulsion motor controller C10 is powered by the ALBUS or the BLBUS busbar; the feeder switch S5 controls whether the propulsion motor controller C5 is powered by the ALBUS or the BLBUS busbar; the feeder switch S3 controls whether the propulsion motor controller C3 is powered by the ARBUS or the BRBUS busbar; and the feeder switch S9 controls whether the propulsion motor controller C9 is powered by the ARBUS busbar. The feeder switch S11 controls whether the propulsion motor controller C11 is powered by the AR bus or the BR bus; the feeder switch S2 controls whether the propulsion motor controller C2 is powered by the BR bus or the AR bus; the feeder switch S8 controls whether the propulsion motor controller C8 is powered by the BR bus or the AR bus; the feeder switch S12 controls whether the propulsion motor controller C12 is powered by the BR bus or the AR bus.

3. The power balance control method for a distributed electric propulsion system according to claim 2, characterized in that, The status information of the four battery packs, as well as the on / off status of the four main channel contactors and two switching channel contactors, form 16 power supply states of the distributed electric propulsion system and 64 power supply conversion modes. The power supply logic table for the 16 power supply states of the distributed electric propulsion system is as follows: When the feeder selector switch S1 is 0, it indicates that the propulsion motor controller C1 is powered by the busbar BL BUS; when it is 1, it is powered by the busbar ALBUS. When the feeder selector switch S2 is 0, it indicates that the propulsion motor controller C2 is powered by the busbar BR BUS; when it is 1, it is powered by the busbar ARBUS. When the feeder selector switch S3 is 0, it indicates that the propulsion motor controller C3 is powered by the busbar AR BUS; when it is 1, it is powered by the busbar BRBUS. When the feeder selector switch S4 is 0, it indicates that the propulsion motor controller C4 is powered by the busbar AL BUS; when it is 1, it is powered by the busbar BLBUS. When the feeder selector switch S5 is 0, it indicates that the propulsion motor controller C5 is powered by the busbar AL BUS; when it is 1, it is powered by the busbar BLBUS. When the feeder selector switch S6 is 0, it indicates that the propulsion motor controller C6 is powered by the busbar BL BUS; when it is 1, it is powered by the busbar ALBUS. When the feeder selector switch S7 is 0, it indicates that the propulsion motor controller C7 is powered by the busbar BL BUS; when it is 1, it is powered by the busbar ALBUS. When the feeder selector switch S8 is 0, it indicates that the propulsion motor controller C8 is powered by the busbar BR BUS; when it is 1, it is powered by the busbar ARBUS. When the feeder selector switch S9 is 0, it indicates that the propulsion motor controller C9 is powered by the busbar AR BUS; when it is 1, it is powered by the busbar BRBUS. When the feeder selector switch S10 is 0, it indicates that the propulsion motor controller C10 is powered by the busbar AL BUS; when it is 1, it is powered by the busbar BL BUS. When the feeder selector switch S11 is 0, it indicates that the propulsion motor controller C11 is powered by the busbar AR BUS; when it is 1, it is powered by the busbar BR BUS. When the feeder selector switch S12 is 0, it indicates that the propulsion motor controller C12 is powered by the busbar BR BUS; when it is 1, it is powered by the busbar AR BUS. The 64 power supply switching modes include bidirectional switching of the following state transition relationships: 1) State 1 <—> State 2; 2) State 1 <—> State 3; 3) State 1 <—> State 4; 4) State 1 <—> State 5; 5) State 2 <—> State 6; 6) State 2 <—> State 7; 7) State 2 <—> State 8; 8) State 3 <—> State 6; 9) State 3 <—> State 9; 10) State 3 <—> State 10; 11) State 4 <—> State 7; 12) State 4 <—> State 9; 13) State 4 <—> State 11; 14) State 5 <—> State 8; 15) State 5 <—> State 10; 16) State 5 <—> State 11; 17) State 6 <—> State 12; 18) State 6 <—> State 13; 19) State 7 <—> State 12; 20) State 7 <—> State 14; 21) State 8 <—> State 13; 22) State 8 <—> State 14; 23) State 9 <—> State 12; 24) State 9 <—> State 15; 25) State 10 <—> State 13; 26) State 10 <—> State 15; 27) State 11 <—> State 14; 28) State 11 <—> State 15; 29) State 12 <—> State 16; 30) State 13 <—> State 16; 31) State 14 <—> State 16; 32) State 15 <—> State 16.

4. The power balance control method for a distributed electric propulsion system according to claim 3, characterized in that, In step 4, the distributed electric propulsion system performs power balance control using an ant colony algorithm, the design of which includes: S1, the objective function for minimizing the cost of powering the motor with the battery pack used for power balance control in a distributed electric propulsion system is: ; in, Let represent the cost of the i-th battery pack performing the j-th task, and N represent the total number of available battery packs. This indicates the number of motors powered by the i-th battery pack; S2, determine the constraints of the objective function, including: battery pack load capacity constraints, power balance constraints, and propulsion motor constraints.

5. The power balance control method for a distributed electric propulsion system according to claim 4, characterized in that, The constraints in S2 are as follows: 1) Battery pack load capacity constraint: Each available battery pack can only power a maximum of 6 propulsion motors, i.e. ; in, This represents the number of motors powered by the i-th battery pack; 2) Power balance constraint: To ensure power balance, the difference in the number of propulsion motors corresponding to each battery pack should not exceed 1, that is: ； 3) Propulsion motor constraint: A propulsion motor can only be powered by one battery pack, that is: ; in, This represents the set of motors powered by the a-th battery pack. This represents the set of motors powered by the b-th battery pack; 4) Battery pack power supply capacity constraints: Based on the different states of the two switching channel contactors, the power supply capacity of each battery pack to each propulsion motor is obtained as follows: ； ； ； ； This indicates the ability of the i-th battery pack to power 12 propulsion motors; 1 indicates that the battery pack can power the motor, and 0 indicates that it cannot power the motor. , , , These represent, in order: BL BAT power supply capacity, AL BAT power supply capacity, AR BAT power supply capacity, and BR BAT power supply capacity. 5) Power supply cost constraints for the propulsion motor: The costs of each battery pack supplying power to each propulsion motor under different operating conditions are as follows: ； ； ； ； in, , , , These represent, in order: BL BAT (motor power supply cost), AL BAT (motor power supply cost), AR BAT (motor power supply cost), and BR BAT (motor power supply cost). BTC When 2=0, it means that when BTC2 is disconnected, the battery pack supplies power to the motors it can supply in sequence, taking into account the power supply capacity of the battery pack. BTC When 2=1, it means that when BTC2 is on, the battery pack supplies power to the motors it can power in sequence. BTC When 1=0, it means that when BTC1 is disconnected, the battery pack supplies power to the motors it can supply in sequence, taking into account the power supply capacity constraints of the battery pack. BTC When 1=1, it means that when BTC1 is on, the battery pack supplies power to the motors it can power in sequence.

6. The power balance control method for a distributed electric propulsion system according to claim 5, characterized in that, The methods for implementing power balance control based on the designed ant colony algorithm include: Step 51: Collect the power supply status of each battery pack and each propulsion motor, and update the status of the battery pack and propulsion motor. Step 52, Initialize parameters: N available battery packs, M available propulsion motors, ant colony algorithm related parameters, total number of ants ant_num, maximum number of iterations NC_max; initialize the tabu list of each ant to empty, the tabu list is used to record the propulsion motors that each ant has selected on its current path, in order to avoid ants repeating paths; Step 53: Randomly select an unpowered available propulsion motor from M propulsion motors for ant k, calculate the transfer probability, and select a propulsion motor that can supply power to the battery pack. Step 54: Update the taboo table, record the propulsion motors that ant k has selected, and repeat step 53 until all ants have no propulsion motors to choose from, then end the current journey; that is, exit the loop of steps 54 and 53 and proceed to step 55. Step 55: Determine whether the power allocation in this iteration satisfies the above constraints. If it does, calculate the objective function value of the power allocation result for each ant and record the optimal power allocation result for this iteration, that is, obtain the propulsion motor corresponding to each available battery pack and update the pheromone; otherwise, return to step 53. Step 56: If the number of iterations NC reaches the maximum value NC_max, then output the optimal power supply result and the algorithm ends; otherwise, NC = NC + 1, and return to step 53.

7. The power balance control method for a distributed electric propulsion system according to claim 6, characterized in that, In step 53, the formula for calculating the probability of an ant moving from the i-th available battery pack to the selected j-th unpowered propulsion motor is as follows: ； in, This represents the pheromone concentration value from the i-th battery pack to the j-th motor. As the heuristic function, the reciprocal of the cost of the battery pack powering the motor is chosen. The pheromone heuristic factor indicates the degree of importance attached to the pheromones left on the path ants traverse. Let be the expected heuristic factor, representing the importance of the heuristic information left behind by the ants when transferring nodes. This represents the set of nodes that have not been visited.

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