Multi-working-point electric propulsion control method under power constraint

Abstract

A multi-working-point electric propulsion control method under power constraint is applied to an electric propulsion system comprising an electric propulsion control unit, a pressure regulation module, a flow control module, a power supply processing unit and an electric thruster, and the electric propulsion system is modeled through the power of the electric propulsion system and an electric propulsion application strategy under the power constraint is formulated. An application method of the multi-working-point electric propulsion system under power constraint is provided, modeling estimation is carried out on the power of the multi-working-point electric propulsion system in the whole life period, and power dynamic matching is carried out and electric propulsion ignition is executed in combination with the power capacity, capable of being provided for the electric propulsion, of the whole device.

Description

Technical Field

[0001] The present invention relates to a multi - operating - point electric propulsion control method under power constraint, belonging to the field of spacecraft technology design. Background Technique

[0002] China's first small - body exploration mission will achieve near - Earth small - body sampling return exploration and main - belt comet exploration, obtaining scientific exploration results in stages and by multiple means. In the asteroid return transfer section, chemical propulsion and electric propulsion are combined to provide thrust for orbital maneuvering, attitude control, etc.; in the transfer section to the main - belt comet, the electric propulsion system provides thrust for orbital maneuvering. Considering the characteristic that the distance between the detector and the sun changes in a large range from 0.89 AU to 2.5 AU during the entire working cycle of electric propulsion, the power provided by the spacecraft to the electric propulsion changes from 3.7 KW to 0.5 KW. In order to more efficiently utilize the power resources of the spacecraft, it is necessary to carry out research on methods for the application of the electric propulsion system under different power constraints.

[0003] When the spacecraft is cruising in deep space, as the distance between the detector and the sun gets farther and farther, the power that the spacecraft can provide to the electric propulsion is continuously decreasing. For example, considering the characteristic that the distance between the detector and the sun changes in a large range from 0.89 AU to 2.5 AU, the power provided by the spacecraft to the electric propulsion changes from 3.7 KW to 0.5 KW. The power of the spacecraft is constrained. How to maximize the use of the spacecraft power and select the most suitable operating point of the electric propulsion for ignition is a problem to be solved. There is still a lack of technical means in this regard in the existing technology. Summary of the Invention

[0004] The technical problem solved by the present invention is: aiming at the problem of the lack of means for maximizing the realization of autonomous ignition control of electric thrust in the current existing technology, a multi - operating - point electric propulsion control method under power constraint is proposed.

[0005] The present invention solves the above - mentioned technical problem through the following technical solutions:

[0006] The multi - operating - point electric propulsion control method under power constraint is characterized by including:

[0007] Establish an electric propulsion power prediction model according to the composition of the electric propulsion system; the electric propulsion system includes an electric propulsion control unit, a pressure regulation module, a flow control module, a power supply processing unit, and an electric thruster;

[0008] Establish an electric propulsion control unit power prediction model and a power supply processing unit power prediction model respectively according to the number of operating points of the electric propulsion system and the output power of the electric propulsion power prediction model;

[0009] The driving power output by the power prediction model of the electric propulsion control unit provides input power for the pressure regulation module and the flow control module of the electric propulsion system respectively; the output power of the power processing unit power prediction model is used as the driving power for the operating points of each electric thruster;

[0010] Calculate the thruster power at each operating point according to the driving power of each electric thruster operating point;

[0011] Perform a power comparison on the thruster power at each operating point, select available operating points, and perform autonomous ignition according to the preset power supply and gas supply parameters of the available operating points;

[0012] During the autonomous ignition process, collect the voltage and current parameters of the electric propulsion control unit and the voltage and current parameters of the power processing unit to calculate the actual ignition power of the propulsion;

[0013] Judge the input power of the integrated electric propulsion and the actual ignition power of the propulsion. If the input power of the integrated electric propulsion is greater than the sum of the actual ignition power of the propulsion and the power margin, then perform subsequent electric propulsion control according to the actual ignition power of the propulsion. Otherwise, perform subsequent electric propulsion control of this autonomous ignition according to the preset power supply and gas supply parameters of autonomous ignition with one gear reduction.

[0014] The electric propulsion power prediction model is:

[0015] P EPS =P EPCU输入 +P PPU输入

[0016] In the formula, P EPS is the total electric propulsion power, P EPCU输入 is the power of the electric propulsion control unit, P PPU输入 is the power of the power processing unit.

[0017] The electric propulsion control unit power prediction model is:

[0018] P EPCU输入 =P EPCU静态 +(P PRM +P XFC ) / (η EPCU -η EPCULt )

[0019] In the formula, P EPCU静态 is the static power of the EPCU when the pressure regulation module and the flow control module are not working, P PRM is the driving power output to the pressure regulation module, P XFC is the driving power output to the flow control module, η EPCU is the power conversion coefficient of the EPCU, η EPCULt is the power degradation coefficient of the EPCU due to the running time.

[0020] The power prediction model of the power supply is as follows:

[0021] P PPU输入 = P PPU静态 +

[0022] (P ITj额定 + P ITj补偿 ) * (1 + α IT系数 + α PPU系数 + α 电缆系数 ) / (η PPUj - η PPUjLt )

[0023] In the formula, P PPU静态 is the static power of the PPU, α IT系数 is the power coefficient caused by the thrust output deviation of the thruster, α PPU系数 is the power coefficient caused by the output voltage and current deviation of the PPU, α 电缆系数 is the wire loss coefficient of the high-voltage cable, η PPUj is the power conversion coefficient of the PPU at the jth operating point, η PPUjLt is the power degradation coefficient of the PPU at the jth operating point due to the operating time, P ITj额定 is the rated power of the thruster at the jth operating point, P ITj补偿 is the compensation power required for the performance degradation of the thruster at the jth operating point, α 电缆系数 is the proportionality coefficient.

[0024] When the operating points of the electric propulsion system are not unique, P ITj is determined respectively according to the rated power P ITj额定 of the thrusters at each operating point, where: ITj补偿

[0025] P ITj = P ITj额定 + P ITj补偿

[0026] When the power supply unit of the electric propulsion system supplies power to the thruster, the power loss at each operating point is determined according to the operating point position and the corresponding proportionality coefficient α 电缆系数 电推实际点火功率 .

[0027] The calculation method of the actual ignition power of the electric propulsion is as follows:

[0028] Measure the bus voltage and bus current of the current power supply unit, and measure the bus voltage and bus current of the current electric propulsion control unit;

[0029] Calculate the actual ignition power P 电推实际点火功率 of the propulsion by using the obtained voltage data and current data. The calculation formula is:

[0030] P 电推实际点火功率 = P EPCU实际输入 + P PPU实际输入

[0031] = U EPCU母线电压 * I EPCU母线电流 + U PPU母线电压 * I PPU母线电流

[0032] Wherein, U EPCU母线电压 、I EPCU母线电流 are the bus voltage and bus current of the electric propulsion control unit, and U PPU母线电压 * I PPU母线电流 are the bus voltage and bus current of the power processing unit.

[0033] The calculation method of the thruster power at each working point is as follows:

[0034] P EPS = P EPCU输入 + P PPU输入

[0035] = P EPCU静态 +(P PRM + P XFC ) / (η EPCU - η EPCULt ) + P PPU静态

[0036] +(P ITj额定 + P ITj补偿 ) * (1 + α IT系数 + α PPU系数 + α 电缆系数 ) / (η PPUj - η PPUjLt )

[0037] In the formula, P EPS is the thruster power at each working point.

[0038] The power P 整器电推输入 that the regulator capable of budgeting the solar array of the power supply system can provide for the electric propulsion ignition, is compared with the actual ignition power P 整器电推输入 to determine the working point required for subsequent electric propulsion control. 电推实际点火功率

[0039] The method for comparing the thruster power at each working point to select an available working point is as follows:

[0040] Determine the preset power margin P 裕量i corresponding to each available working point, and judge whether P 整器电推输入 ≥ (P EPSi + P 裕量i ). If the current thruster power P整器电推输入 If the criterion is met, it is determined as an available operating point; otherwise, it is unavailable.

[0041] The preset power supply and gas supply parameters of the operating point are determined according to the power supply and gas supply parameters of each operating point bound in the software of the electric propulsion control unit;

[0042] Preset power margin P 裕量i It is determined according to the power margin parameters of each operating point bound in the software of the electric propulsion control unit.

[0043] The advantages of the present invention compared with the prior art are as follows:

[0044] A multi-operating point electric propulsion control method under power constraint provided by the present invention innovatively designs a multi-operating point electric propulsion application method under power constraint according to the application background of the electric thruster, solves the problem of efficient application of electric propulsion under power constraint, and at the same time, based on the parameters obtained from ground tests, establishes an electric propulsion power model covering the full operating conditions and the full life cycle. By means of the method of optimizing and iteratively selecting the operating point and the power margin judgment means, it is possible to select a more suitable operating point for ignition and make more efficient use of the power resources of the entire vehicle. Description of the Drawings

[0045] Figure 1 It is a schematic diagram of the multi-operating point electric propulsion control method under power constraint provided by the present invention. Detailed Embodiment

[0046] A multi-operating point electric propulsion control method under power constraint is applied to an electric propulsion system including an electric propulsion control unit, a pressure regulation module, a flow control module, a power supply processing unit, and an electric thruster. By modeling the power of the electric propulsion system and formulating an electric propulsion application strategy under power constraint, a multi-operating point electric propulsion system application method under power constraint is proposed. The power of the multi-operating point electric propulsion system within the full life cycle is modeled and estimated, and combined with the power capability that the entire vehicle can provide to the electric propulsion, power dynamic matching is performed and electric propulsion ignition is executed.

[0047] The multi-operating point electric propulsion control method under power constraint comprises the following steps:

[0048] Establish an electric propulsion power prediction model according to the composition of the electric propulsion system; the electric propulsion system includes an electric propulsion control unit, a pressure regulation module, a flow control module, a power supply processing unit, and an electric thruster;

[0049] Establish an electric propulsion control unit power prediction model and a power supply processing unit power prediction model respectively according to the number of operating points of the electric propulsion system and the output power of the electric propulsion power prediction model;

[0050] The driving power output by the power prediction model of the electric propulsion control unit provides input power for the pressure regulation module and the flow control module of the electric propulsion system respectively; the output power of the power processing unit power prediction model is used as the driving power for the operating points of each electric thruster;

[0051] Calculate the thruster power of each operating point according to the driving power of each electric thruster operating point;

[0052] Conduct a power comparison of the thruster power of each operating point, select available operating points, and perform autonomous ignition according to the preset power supply and gas supply parameters of the available operating points;

[0053] During the autonomous ignition process, collect the voltage and current parameters of the electric propulsion control unit and the voltage and current parameters of the power processing unit to calculate the actual ignition power of the propulsion;

[0054] Judge the input power of the integrated electric propulsion and the actual ignition power of the propulsion. If the input power of the integrated electric propulsion is greater than the sum of the actual ignition power of the propulsion and the power margin, then perform subsequent electric propulsion control according to the actual ignition power of the propulsion. Otherwise, perform subsequent electric propulsion control of this autonomous ignition according to the preset power supply and gas supply parameters of autonomous ignition with one gear reduction.

[0055] The electric propulsion power prediction model is:

[0056] P EPS =P EPCU输入 +P PPU输入

[0057] In the formula, P EPS is the total electric propulsion power, P EPCU输入 is the power of the electric propulsion control unit, P PPU输入 is the power of the power processing unit.

[0058] The electric propulsion control unit power prediction model is:

[0059] P EPCU输入 =P EPCU静态 +(P PRM +P XFC ) / (η EPCU -η EPCULt )

[0060] In the formula, P EPCU静态 is the static power of the EPCU when the pressure regulation module and the flow control module are not working, P PRM is the driving power output to the pressure regulation module, P XFC is the driving power output to the flow control module, η EPCU is the power conversion coefficient of the EPCU, η EPCULt is the power degradation coefficient of the EPCU due to the running time.

[0061] The power prediction model of the power supply is as follows:

[0062] P PPU输入 = P PPU静态 +

[0063] (P ITj额定 + P ITj补偿 ) * (1 + α IT系数 + α PPU系数 + α 电缆系数 ) / (η PPUj - η PPUjLt )

[0064] Wherein, P PPU静态 is the static power of the PPU, α IT系数 is the power coefficient caused by the thrust output deviation of the thruster, α PPU系数 is the power coefficient caused by the output voltage and current deviation of the PPU, α 电缆系数 is the wire loss coefficient of the high-voltage cable, η PPUj is the power conversion coefficient of the PPU at the j-th operating point, η PPUjLt is the power reduction coefficient of the PPU at the j-th operating point due to the running time, P ITj额定 is the rated power of the thruster at the j-th operating point, P ITj补偿 is the compensation power required for the performance degradation of the thruster at the j-th operating point, α 电缆系数 is the proportionality coefficient.

[0065] When the operating points of the electric propulsion system are not unique, P ITj is determined respectively according to the rated power P ITj额定 of the thrusters at each operating point, where: ITj补偿

[0066] P ITj = P ITj额定 + P ITj补偿

[0067] When the power supply unit of the electric propulsion system supplies power to the thruster, the power loss at each operating point is determined according to the operating point position and the corresponding proportionality coefficient α 电缆系数 .

[0068] The calculation method of the actual ignition power of the electric propulsion is as follows:

[0069] Measure the bus voltage and bus current of the electric propulsion control unit corresponding to the drive power output by the power prediction model of the current electric propulsion control unit, and the bus voltage and bus current of the current power supply unit;

[0070] Calculate the actual ignition power P 电推实际点火功率 of the propulsion by using the obtained voltage data and current data. The calculation formula is:​

[0071] P 电推实际点火功率 = P EPCU实际输入 + P PPU实际输入

[0072] = U EPCU母线电压 * I EPCU母线电流 + U PPU母线电压 * I PPU母线电流

[0073] Wherein, U EPCU母线电压 、I EPCU母线电流 are the bus voltage and bus current of the electric propulsion control unit, and U PPU母线电压 * I PPU母线电流 are the bus voltage and bus current of the power processing unit.

[0074] The calculation method of the thruster power at each operating point is as follows:

[0075] P EPS = P EPCU输入 + P PPU输入

[0076] = P EPCU静态 +(P PRM + P XFC ) / (η EPCU - η EPCULt ) + P PPU静态

[0077] +(P ITj额定 + P ITj补偿 ) * (1 + α IT系数 + α PPU系数 + α 电缆系数 ) / (η PPUj - η PPUjLt )

[0078] In the formula, P EPS is the thruster power at each operating point.

[0079] The thruster power at each operating point is the thruster power P 整器电推输入 calculated according to the driving power of each preset electric thruster operating point. By comparing P 整器电推输入 with the actual ignition power P 电推实际点火功率 of the propulsion, the power required for subsequent electric propulsion control is determined.

[0080] The method for comparing the thruster power at each operating point to select available operating points is as follows:

[0081] Determine the preset power margin P 裕量i corresponding to each available operating point, and judge whether P 整器电推输入 ≥ (P EPSi + P 裕量i), if the current thruster power P 整器电推输入 meets the criterion, it is determined as an available operating point; otherwise, it is unavailable.

[0082] The preset power supply and gas supply parameters of the operating point are determined according to the power supply and gas supply parameters of each operating point bound in the electric propulsion control unit software;

[0083] The preset power margin P 裕量i is determined according to the power margin parameters of each operating point bound in the electric propulsion control unit software.

[0084] The following is a further description in conjunction with the accompanying drawings of the specification and preferred embodiments:

[0085] In the current embodiment, as Figure 1 shown, the specific design process of this embodiment is as follows:

[0086] This embodiment proposes an application method for a multi-operating point electric propulsion system under power constraints, models and estimates the power of the multi-operating point electric propulsion system throughout its life cycle, performs power dynamic matching in combination with the power capability that the integrated device can provide to the electric propulsion, and executes electric propulsion ignition.

[0087] 1. Power prediction model of multi-operating point electric propulsion system

[0088] The electric propulsion system includes an electric propulsion control unit (EPCU), a pressure regulation module (PRM), a flow control module (XFC), a power supply processing unit (PPU), and an electric thruster (IT). In terms of power transfer: the electric propulsion control unit provides driving power for the pressure regulation module and the flow control module; the power supply processing unit supplies power to the electric thruster; the power flow of the electric propulsion system is shown in Figure 1 .

[0089] P EPS = P EPCU输入 + P PPU输入 (1)

[0090] P EPS is the total power of the electric propulsion system;

[0091] P EPCU输入 is the power of the electric propulsion control unit;

[0092] P PPU输入 is the power of the power supply processing unit;

[0093] 1) Power model of the electric propulsion control unit

[0094] The power of the electric propulsion control unit (P EPCU输入 ) includes its own static power (P EPCU静态 ) and the driving power output to the pressure regulation module (P PRM) and the driving power (P XFC ) output to the flow control module. For a multi-operating-point electric propulsion system, the gas supply parameters at each operating point are regulated by a pressure closed-loop and a flow closed-loop, and the required power is the same. The power prediction model of the electric propulsion control unit is as follows:

[0095] P EPCU输入 = P EPCU静态 + (P PRM + P XFC ) / (η EPCU - η EPCULt ) (2)

[0096] P EPCU静态 is the static power of the EPCU when the pressure regulation module and the flow control module are not working;

[0097] P PRM is the driving power output to the pressure regulation module;

[0098] P XFC is the driving power output to the flow control module;

[0099] η EPCU is the power conversion coefficient of the EPCU;

[0100] η EPCULt is the efficiency degradation of the EPCU due to the running time and device aging.

[0101] 2) Power prediction model of the power processing unit

[0102] The power calculation of the power processing unit includes its own static power P PPU静态 , output power and power conversion coefficient, where the output power calculation includes the power loss of the high-voltage cable and the power of the thruster.

[0103] For a multi-operating-point electric propulsion system, the power supply parameters at each operating point are different, and the thruster power P ITj at each operating point is different, as shown in the formula

[0104] P ITj = P ITj额定 + P ITj补偿 (3)

[0105] P ITj is the rated power of the thruster at the jth operating point;

[0106] P ITj额定 is the rated power of the thruster at the jth operating point;

[0107] P ITj补偿 is the compensation power required for the performance degradation of the thruster at the jth operating point;

[0108] Similarly, when the PPU powers the thruster, the power losses at each operating point in the high-voltage cable are also different, usually considered in a certain proportion, and the proportionality coefficient is α 电缆系数 .

[0109] The power prediction model of the power processing unit is established as follows:

[0110] P PPU输入 =

[0111] P PPU静态 +

[0112] (P ITj额定 + P ITj补偿 ) * (1 + α IT系数 + α PPU系数 + α 电缆系数 ) / (η PPUj - η PPUjLt ) (4)

[0113] P PPU静态 is the static power of the PPU;

[0114] α IT系数 is the power coefficient caused by the thrust output deviation of the thruster;

[0115] α PPU系数 is the power coefficient caused by the output voltage and current deviation of the PPU;

[0116] α 电缆系数 is the wire loss coefficient of the high-voltage cable;

[0117] η PPUj is the power conversion coefficient of the PPU at the jth operating point;

[0118] η PPUjLt is the efficiency reduction of the PPU at the jth operating point due to the running time and device aging.

[0119] After power prediction modeling for each module of the electric propulsion system, substituting equations (2) and (4) into (1), the detailed power model of the electric propulsion system is obtained as follows:

[0120] P EPS = P EPCU输入 + P PPU输入 (5)

[0121] = P EPCU静态 +(P PRM + P XFC ) / (η EPCU - η EPCULt )+ P PPU静态

[0122] +(PITj额定 +P ITj补偿 )*(1 + α IT系数 +α PPU系数 +α 电缆系数 ) / (η PPUj -η PPUjLt )

[0123] During the electric propulsion ignition process, the actual ignition power P of the electric propulsion can be calculated by using the telemetry of the bus voltage and current of the electric propulsion control unit and the telemetry of the bus voltage and current of the power processing unit. 电推实际点火功率 :

[0124] P 电推实际点火功率 = P EPCU实际输入 +P PPU实际输入 (6)

[0125] = U EPCU母线电压 *I EPCU母线电流 +U PPU母线电压 *I PPU母线电流

[0126] 2. Electric Propulsion Application Strategy under Power Constraint

[0127] By establishing a power prediction model for the electric propulsion system, the electric propulsion power at each working point can be predicted, and the power resources of the entire spacecraft can be utilized more efficiently. The specific steps for the application of electric propulsion under power constraint are as follows:

[0128] a. According to the solar array capacity budget, calculate the power that the spacecraft can provide for electric propulsion ignition, denoted as

[0129] P 整器电推输入 ;

[0130] b. Predict the electric propulsion power at each working point according to formula (5), denoted as P EPSi ;

[0131] c. Conduct a comparison iteration for working point i according to P 整器电推输入 ≥(P EPSi +P 裕量i ), and select the appropriate electric propulsion working point i;

[0132] d. Start the autonomous ignition of the electric propulsion according to the power supply and gas supply parameters of working point i;

[0133] e. During the ignition process, collect the bus voltage and current of the electric propulsion control unit and the bus voltage and current of the power processing unit, and calculate the working power P of the electric propulsion through formula (6). 电推实际点火功率i , and judge whether P 整器电推输入 is greater than or equal to (P 电推实际点火功率i +P 裕量i ). If not, adjust the electric propulsion ignition according to the gas supply and power supply parameters of the (i - 1)th working point.

[0134] In view of the application background, this embodiment innovatively designs a multi - operating - point electric propulsion application method under power constraints, solves the problem of efficient application of electric propulsion under power constraints, and at the same time, based on the parameters obtained from ground tests, establishes an electric propulsion power model that covers the entire operating conditions and the entire life cycle, and can achieve the selection of the appropriate operating point for ignition through evaluation and iteration means.

[0135] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention all fall within the protection scope of the technical solution of the present invention.

[0136] The content not detailedly described in the specification of the present invention belongs to the well - known technology of those skilled in the art.

Claims

1. A multi-operating point electric propulsion control method under power constraints, characterized in that include: An electric propulsion power estimation model is established according to the composition of the electric propulsion system; the electric propulsion system includes an electric propulsion control unit, a pressure regulating module, a flow control module, a power processing unit and an electric thruster; According to the number of working points of the electric propulsion system and the output power of the electric propulsion power estimation model, an electric propulsion control unit power estimation model and a power processing unit power estimation model are respectively established; The driving power output by the power estimation model of the electric propulsion control unit is used to provide input power to the pressure regulation module and the flow control module of the electric propulsion system; The output power of the power estimation model of the power processing unit is used as the driving power of each electric thruster working point; Calculate the thruster power at each working point based on the driving power at each electric thruster working point; Compare the thruster power of each working point, select the available working point, and perform autonomous ignition according to the preset power supply and air supply parameters of the available working point; During the autonomous ignition process, the voltage and current parameters of the electric propulsion control unit and the voltage and current parameters of the power processing unit are collected to calculate the actual ignition power of the propulsion; The electric propulsion input power of the whole device and the actual ignition power of the propulsion are judged. If the electric propulsion input power of the whole device is greater than the sum of the actual ignition power of the propulsion and the power margin, the subsequent electric propulsion control is carried out according to the actual ignition power. Otherwise, the subsequent electric propulsion control of this autonomous ignition is carried out according to the preset power supply and air supply parameters of the autonomous ignition that is reduced by one gear.

2. The multi-operating point electric propulsion control method under power constraint according to claim 1, characterized in that: The electric propulsion power estimation model is: P EPS =P EPCU输入 +P PPU输入 Where P EPS is the total electric propulsion power, P EPCU输入 is the power of the electric propulsion control unit, P PPU输入 is the power processing unit power.

3. The multi-operating point electric propulsion control method under power constraint according to claim 1, characterized in that: The power estimation model of the electric propulsion control unit is: P.S EPCU输入 JP EPCU静态 +(P PRM +P XFC ) / (η EPCU -η EPCULt ) Where P EPCU静态 is the static power of EPCU when the pressure regulating module and flow control module are not working, P PRM is the driving power output to the pressure regulating module, P XFC is the driving power output to the flow control module, η EPCU is the power conversion coefficient of EPCU, η EPCULt is the power reduction coefficient of EPCU due to running time.

4. The multi-operating point electric propulsion control method under power constraint according to claim 1, characterized in that: The power estimation model of the power processing unit is: P PPU输入 =P PPU静态 + (P ITj额定 +P ITj补偿 )*(1+a IT系数 +a PPU系数 +a 电缆系数 ) / (or PPUj -or PPUjLt ) Where P PPU静态 is the static power of PPU, α IT系数 is the power coefficient caused by the thrust output deviation of the thruster, α PPU系数 is the power coefficient caused by the PPU output voltage and current deviation, α 电缆系数 is the high voltage cable conductor loss coefficient, η PPUj is the power conversion coefficient of the PPU at the jth operating point, η PPUjLt is the power reduction coefficient of the jth operating point PPU due to the running time, P ITj额定 is the rated power of the thruster at the jth operating point, P ITj补偿 is the compensation power required for the thruster due to performance degradation at the jth operating point, α 电缆系数 is the proportionality coefficient.

5. The method for controlling electric propulsion at multiple operating points under power constraints according to claim 4, characterized in that: When the working point of the electric propulsion system is not unique, according to the thruster rated power P at each working point ITj Determine P ITj额定 , P ITj补偿 ,in: P ITj =P ITj额定 +P ITj补偿 When the power processing unit of the electric propulsion system supplies power to the thruster, the power loss at each working point is calculated according to the working point position and the corresponding proportional coefficient α. 电缆系数 Sure.

6. The multi-operating point electric propulsion control method under power constraint according to claim 1, characterized in that: The calculation method of the actual ignition power of electric propulsion is: Measure the bus voltage and bus current of the current power processing unit, and measure the bus voltage and bus current of the current electric propulsion control unit; The actual ignition power P is calculated using the obtained voltage and current data. 电推实际点火功率 , the calculation formula is: P 电推实际点火功率 =P EPCU实际输入 +P PPU实际输入 =U EPCU母线电压 *AND EPCU母线电流 +U PPU母线电压 *AND PPU母线电流 Among them, U EPCU母线电压 ,I EPCU母线电流 is the bus voltage and bus current of the electric propulsion control unit, U PPU母线电压 *I PPU母线电流 are the bus voltage and bus current of the power processing unit.

7. The multi-operating point electric propulsion control method under power constraint according to claim 6, characterized in that: The thruster power calculation method for each working point is: P EPS =P EPCU输入 +P PPU输入 =P EPCU静态 +(P PRM +P XFC ) / (or EPCU -or EPCULt )+P PPU静态 +(P ITj额定 +P ITj补偿 )*(1+a IT系数 +a PPU系数 +a 电缆系数 ) / (or PPUj -or PPUjLt ) Where P EPS is the thruster power at each working point.

8. The multi-operating point electric propulsion control method under power constraint according to claim 1, characterized in that: The power P that the whole device can provide for electric propulsion ignition is estimated according to the solar array capacity of the power supply system. 整器电推输入 , through P 整器电推输入 The actual ignition power P 电推实际点火功率 A comparison is made to determine the required operating point for subsequent electric propulsion control.

9. The multi-operating point electric propulsion control method under power constraint according to claim 1, characterized in that: The method for comparing the thruster power at each working point to select the available working point is: Determine the preset power margin P corresponding to each available operating point 裕量i , judge P 整器电推输入 ≥(P EPSi +P 裕量i ), if the current thruster power P 整器电推输入 If the criterion is met, it is determined to be an available working point, otherwise it is unavailable.

10. The multi-operating point electric propulsion control method under power constraint according to claim 1, characterized in that: The preset power supply and air supply parameters of the working point are determined according to the power supply and air supply parameters of each working point bound in the electric propulsion control unit software; Preset power margin P 裕量i It is determined according to the power margin parameters of each operating point bound in the electric propulsion control unit software.

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