A method for controlling multi-working-point electric propulsion under power constraint

Abstract

The application relates to a multi-working-point electric propulsion control method under power constraint, which is applied to an electric propulsion system comprising an electric propulsion control unit, a pressure regulating module, a flow control module, a power processing unit and an electric thruster, and is characterized in that: the power of the electric propulsion system is modeled, an electric propulsion application strategy under power constraint is formulated, a multi-working-point electric propulsion system application method under power constraint is proposed, the power of the multi-working-point electric propulsion system in the whole life cycle is modeled and estimated, the power dynamic matching is carried out in combination with the power capability of the whole machine which can be provided to the electric thruster, and the electric propulsion ignition is executed.

Description

Technical Field

[0001] This invention relates to a multi-operating-point electric propulsion control method under power constraints, belonging to the field of spacecraft technology design. Background Technology

[0002] my country's first small body exploration mission will achieve near-Earth small body sample return and main-belt comet exploration, obtaining scientific results in stages and through multiple means. During the asteroid return transfer phase, a combination of chemical and electric propulsion will provide thrust for orbital maneuvers and attitude control; during the transfer phase to the main-belt comet, the electric propulsion system will provide thrust for orbital maneuvers. Given the significant variation in the spacecraft's distance from the Sun throughout its entire operational cycle (ranging from 0.89 AU to 2.5 AU), the total power supplied to electric propulsion will vary from 3.7 kW to 0.5 kW. To more efficiently utilize the spacecraft's power resources, research is needed on methods for applying electric propulsion systems under different power constraints.

[0003] As spacecraft cruise in deep space, the power they can provide for electric propulsion decreases as the distance between the probe and the sun increases. For example, given the wide variation in distance from the sun, from 0.89 AU to 2.5 AU, the power available for electric propulsion varies from 3.7 kW to 0.5 kW. Since spacecraft power is constrained, maximizing the utilization of total spacecraft power and selecting the most suitable ignition point for electric propulsion are problems that need to be solved. Current technology still lacks the necessary solutions in this regard. Summary of the Invention

[0004] The technical problem solved by this invention is: addressing the lack of means to maximize the autonomous ignition control of electric thrust in the existing technology, a multi-operating-point electric propulsion control method under power constraints is proposed.

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

[0006] A multi-operating-point electric propulsion control method under power constraints, characterized by comprising:

[0007] An electric propulsion power prediction model is established based on 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 processing unit, and an electric thruster;

[0008] Based on the number of operating points of the electric propulsion system and the output power of the electric propulsion power prediction model, power prediction models for the electric propulsion control unit and power processing unit are established respectively.

[0009] The drive power output from the electric propulsion control unit power prediction model is used to provide input power to the pressure regulation module and flow control module of the electric propulsion system; the output power of the power processing unit power prediction model is used as the drive power at the operating point of each electric thruster.

[0010] Calculate the thruster power at each operating point based on the drive power at each electric thruster operating point;

[0011] The thruster power at each working point is compared, an available working point is selected, and autonomous ignition is performed according to the preset power supply and gas supply parameters of the available working point.

[0012] During autonomous ignition, 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.

[0013] The system compares the input power of the electric propulsion unit with the actual ignition power of the propulsion. If the input power of the electric propulsion unit is greater than the sum of the actual ignition power and the power margin, the subsequent electric propulsion control is performed according to the actual ignition power. Otherwise, the subsequent electric propulsion control for this autonomous ignition is performed according to the preset power supply and gas supply parameters for autonomous ignition that are reduced by one level.

[0014] The electric propulsion power prediction model is as follows:

[0015] P EPS =P EPCU输入 +P PPU输入

[0016] In the formula, P EPS P represents the total power of electric propulsion. EPCU输入 For the power of the electric propulsion control unit, P PPU输入 This refers to the power of the power processing unit.

[0017] The power prediction model for the electric propulsion control unit is as follows:

[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 P is the static power of the EPCU when the pressure regulation module and flow control module are not working. PRM To provide the drive power to the pressure regulation module, P XFC η is the drive power output to the flow control module. EPCU η is the power conversion factor of the EPCU. EPCULt This represents the power reduction factor of the EPCU over operating time.

[0020] The power supply prediction model 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 For the static power of the PPU, α IT系数 α is the power coefficient caused by the thrust output deviation of the thruster. PPU系数 α is the power factor caused by the deviation of PPU output voltage and current. 电缆系数 η is the loss coefficient of high-voltage cable conductors. PPUj Let η be the power conversion factor of the PPU at the j-th operating point. PPUjLt Let P be the power reduction factor of the PPU at the j-th operating point due to runtime. ITj额定 P is the rated power of the thruster at the j-th operating point. ITj补偿 α is the compensation power required for the thruster to degrade due to performance degradation at the j-th operating point. 电缆系数 This is the proportionality coefficient.

[0024] When the operating point of the electric propulsion system is not unique, the thruster rated power P at each operating point should be considered. ITj Determine P respectively ITj额定 P ITj补偿 ,in:

[0025] P ITj =P ITj额定 +P ITj补偿

[0026] When the power processing unit of the electric propulsion system supplies power to the thruster, the power loss at each operating point depends on the operating point location and the corresponding proportionality coefficient α. 电缆系数 Sure.

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

[0028] 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;

[0029] The actual ignition power P of the propulsion system was calculated using the obtained voltage and current data. 电推实际点火功率 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] Among them, U EPCU母线电压 I EPCU母线电流 For the electric propulsion control unit bus voltage and bus current, U PPU母线电压 *I PPU母线电流 These are the bus voltage and bus current of the power processing unit.

[0033] The method for calculating the thruster power at each operating 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 This represents the thruster power at each operating point.

[0038] The power P that the ignition unit can provide to the electric propulsion ignition is estimated based on the solar array capability of the power supply system. 整器电推输入 Through P 整器电推输入 With the actual ignition power P 电推实际点火功率 The comparison was used to determine the operating point required for subsequent electric propulsion control.

[0039] The method for selecting an usable operating point by comparing the thruster power at each operating point is as follows:

[0040] Determine the preset power margin P corresponding to each available operating point. 裕量i Determine 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 criteria are met, the work point is determined to be usable; otherwise, it is unusable.

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

[0042] Preset power margin P 裕量i The power margin parameters for each operating point are determined based on the parameters configured in the electric propulsion control unit software.

[0043] The advantages of this invention compared to the prior art are:

[0044] This invention provides a multi-operating-point electric propulsion control method under power constraints. Based on the application background of electric thrusters, it innovatively designs a multi-operating-point electric propulsion application method under power constraints, solving the problem of efficient application of electric propulsion under power constraints. At the same time, based on the parameters obtained from ground tests, an electric propulsion power model is established, covering all operating conditions and the entire life cycle. Through the optimization and iterative selection method of operating point and the power margin judgment means, a more suitable operating point can be selected for ignition, and the power resources of the whole device can be utilized more efficiently. Attached Figure Description

[0045] Figure 1 A schematic diagram of the power-constrained multi-operating-point electric propulsion control method provided by the present invention. Detailed Implementation

[0046] A power-constrained multi-operating-point electric propulsion control method is proposed and applied to an electric propulsion system including an electric propulsion control unit, a pressure regulation module, a flow control module, a power processing unit, and an electric thruster. By modeling the power of the electric propulsion system and formulating an electric propulsion application strategy under power constraints, a method for applying a power-constrained multi-operating-point electric propulsion system is proposed. The power of the multi-operating-point electric propulsion system is modeled and estimated throughout its entire life cycle. Combined with the power capability that the entire device can provide to the electric propulsion, dynamic power matching is performed and electric propulsion ignition is executed.

[0047] A multi-operating-point electric propulsion control method under power constraints, the steps of which are as follows:

[0048] An electric propulsion power prediction model is established based on 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 processing unit, and an electric thruster;

[0049] Based on the number of operating points of the electric propulsion system and the output power of the electric propulsion power prediction model, power prediction models for the electric propulsion control unit and power processing unit are established respectively.

[0050] The drive power output from the electric propulsion control unit power prediction model is used to provide input power to the pressure regulation module and flow control module of the electric propulsion system; the output power of the power processing unit power prediction model is used as the drive power at the operating point of each electric thruster.

[0051] Calculate the thruster power at each operating point based on the drive power at each electric thruster operating point;

[0052] The thruster power at each working point is compared, an available working point is selected, and autonomous ignition is performed according to the preset power supply and gas supply parameters of the available working point.

[0053] During autonomous ignition, 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.

[0054] The system compares the input power of the electric propulsion unit with the actual ignition power of the propulsion. If the input power of the electric propulsion unit is greater than the sum of the actual ignition power and the power margin, the subsequent electric propulsion control is performed according to the actual ignition power. Otherwise, the subsequent electric propulsion control for this autonomous ignition is performed according to the preset power supply and gas supply parameters for autonomous ignition that are reduced by one level.

[0055] The electric propulsion power prediction model is as follows:

[0056] P EPS =P EPCU输入 +P PPU输入

[0057] In the formula, P EPS P represents the total power of electric propulsion. EPCU输入 For the power of the electric propulsion control unit, P PPU输入 This refers to the power of the power processing unit.

[0058] The power prediction model for the electric propulsion control unit is as follows:

[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 P is the static power of the EPCU when the pressure regulation module and flow control module are not working. PRM To provide the drive power to the pressure regulation module, P XFC η is the drive power output to the flow control module. EPCU η is the power conversion factor of the EPCU. EPCULt This represents the power reduction factor of the EPCU over operating time.

[0061] The power supply prediction model 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] In the formula, P PPU静态 For the static power of the PPU, α IT系数 α is the power coefficient caused by the thrust output deviation of the thruster. PPU系数 α is the power factor caused by the deviation of PPU output voltage and current. 电缆系数 η is the loss coefficient of high-voltage cable conductors. PPUj Let η be the power conversion factor of the PPU at the j-th operating point. PPUjLt Let P be the power reduction factor of the PPU at the j-th operating point due to runtime. ITj额定 P is the rated power of the thruster at the j-th operating point. ITj补偿 α is the compensation power required for the thruster to degrade due to performance degradation at the j-th operating point. 电缆系数 This is the proportionality coefficient.

[0065] When the operating point of the electric propulsion system is not unique, the thruster rated power P at each operating point should be considered. ITj Determine P respectively ITj额定 P ITj补偿 ,in:

[0066] P ITj =P ITj额定 +P ITj补偿

[0067] When the power processing unit of the electric propulsion system supplies power to the thruster, the power loss at each operating point depends on the operating point location and the corresponding proportionality coefficient α. 电缆系数 Sure.

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

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

[0070] The actual ignition power P of the propulsion system was calculated using the obtained voltage and current data. 电推实际点火功率 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] Among them, U EPCU母线电压 I EPCU母线电流 For the electric propulsion control unit bus voltage and bus current, U PPU母线电压 *I PPU母线电流 These are the bus voltage and bus current of the power processing unit.

[0074] The method for calculating 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 This represents the thruster power at each operating point.

[0079] The thruster power at each operating point is the thruster power P calculated based on the preset drive power of each electric thruster operating point. 整器电推输入 Through P 整器电推输入 With the actual ignition power P 电推实际点火功率 The power required for subsequent electric propulsion control is determined by comparison.

[0080] The method for selecting an usable operating point by comparing the thruster power at each operating point is as follows:

[0081] Determine the preset power margin P corresponding to each available operating point. 裕量i Determine P 整器电推输入 ≥(P EPSi +P 裕量iIf the current thruster power P 整器电推输入 If the criteria are met, the work point is determined to be usable; otherwise, it is unusable.

[0082] The preset power supply and gas supply parameters for each working point are determined based on the power supply and gas supply parameters for each working point loaded in the electric propulsion control unit software.

[0083] Preset power margin P 裕量i The power margin parameters for each operating point are determined based on the parameters configured in the electric propulsion control unit software.

[0084] The following description, in conjunction with the accompanying drawings and preferred embodiments, provides further details:

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

[0086] This embodiment proposes a method for applying a multi-operating-point electric propulsion system under power constraints. The power of the multi-operating-point electric propulsion system is modeled and estimated throughout its entire lifespan. Combined with the power capability that the entire device can provide to the electric propulsion, dynamic power matching is performed and electric propulsion ignition is executed.

[0087] 1. Power prediction model for multi-operating-point electric propulsion systems

[0088] The electric propulsion system includes an electric propulsion control unit (EPCU), a pressure regulation module (PRM), a flow control module (XFC), a power processing unit (PPU), and an electric thruster (IT). In terms of power delivery: the electric propulsion control unit provides drive power to the pressure regulation module and the flow control module; the power processing unit provides power to the electric thruster; the power flow of the electric propulsion system is as follows: Figure 1 .

[0089] P EPS =P EPCU输入 +P PPU输入 (1)

[0090] P EPS This represents the total power of the electric propulsion system.

[0091] P EPCU输入 Power for the electric propulsion control unit;

[0092] P PPU输入 This refers to the power of the power processing unit;

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

[0094] Electric propulsion control unit power (P) EPCU输入 This includes its own static power (P) EPCU静态 ) and the drive power (P) output to the pressure regulation module PRM) and the drive power (P) output to the flow control module XFC For multi-operating-point electric propulsion systems, the gas supply parameters at each operating point are regulated by pressure and flow closed-loop control, and the required power is the same. The power prediction model for 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 The static power of the EPCU when the pressure regulation module and flow control module are not working;

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

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

[0099] η EPCU The power conversion factor of the EPCU;

[0100] η EPCULt The efficiency of the EPCU decreases due to operating time and device aging.

[0101] 2) Power prediction model for 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 factor, 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 are different at each operating point, and the thruster power P at each operating point is different. ITj They are different, see the formula.

[0104] P ITj =P ITj额定 +P ITj补偿 (3)

[0105] P ITj The rated power of the thruster at the j-th operating point;

[0106] P ITj额定 The rated power of the thruster at the j-th operating point;

[0107] P ITj补偿 This represents the compensation power required for the thruster to degrade due to performance degradation at the j-th operating point.

[0108] Similarly, when the PPU supplies power to the thruster, the power loss at each operating point in the high-voltage cable is different, and is usually considered in a certain proportion, with a proportionality coefficient of α. 电缆系数 .

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

[0110] P PPU输入 =P PPU静态 +(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)

[0111] P PPU静态 This refers to the static power of the PPU;

[0112] α IT系数 The power coefficient caused by the thrust output deviation of the thruster;

[0113] α PPU系数 The power factor caused by the deviation of PPU output voltage and current;

[0114] α 电缆系数 This refers to the loss coefficient of high-voltage cable conductors;

[0115] η PPUj Let be the power conversion coefficient of the PPU at the j-th operating point;

[0116] η PPUjLt The efficiency of the PPU at the j-th operating point decreases due to runtime and device aging.

[0117] After modeling the power prediction of each module of the electric propulsion system, substituting formulas (2) and (4) into (1), the detailed power model of the electric propulsion system is obtained as follows:

[0118] P EPS =P EPCU输入 +P PPU输入 (5)

[0119] =P EPCU静态 +(P PRM +P XFC ) / (η EPCU -η EPCULt )+P PPU静态

[0120] +(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 )

[0121] During electric propulsion ignition, the actual ignition power P of the electric propulsion can be calculated using telemetry of the bus voltage and current of the electric propulsion control unit and the power processing unit. 电推实际点火功率 :

[0122] P 电推实际点火功率 =P EPCU实际输入 +P PPU实际输入 (6)

[0123] =U EPCU母线电压 *I EPCU母线电流 +U PPU母线电压 *I PPU母线电流

[0124] 2. Electric Propulsion Application Strategies under Power Constraints

[0125] Establishing a power prediction model for the electric propulsion system allows for the estimation of electric propulsion power at various operating points, leading to more efficient utilization of the entire system's power resources. The specific steps for applying electric propulsion under power constraints are as follows:

[0126] a. Based on the solar array's capabilities, estimate the power the entire unit can provide for electric propulsion ignition, denoted as...

[0127] P 整器电推输入 ;

[0128] b. Estimate the electric propulsion power at each operating point according to formula (5), denoted as P. EPSi ;

[0129] c. According to P 整器电推输入 ≥(P EPSi +P 裕量i Perform comparative iterations at operating point i to select a suitable electric propulsion operating point i;

[0130] d. Start autonomous ignition of electric propulsion according to the power supply and gas supply parameters at working point i;

[0131] e. During ignition, the bus voltage and current of the electric propulsion control unit and the bus voltage and current of the power processing unit are collected, and the electric propulsion working power P is calculated using formula (6). 电推实际点火功率i Determine P 整器电推输入 Is it 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 and power supply parameters of the (i-1)th working point.

[0132] This embodiment innovatively designs a multi-operating-point electric propulsion application method under power constraints, addressing the challenge of efficient electric propulsion application under power constraints. Furthermore, based on parameters obtained from ground tests, an electric propulsion power model is established, covering all operating conditions and the entire life cycle. This model enables the selection of a suitable operating point for ignition through evaluation and iteration.

[0133] Although the present invention has been disclosed above with reference to 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 solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

[0134] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A method of multi-operating point electric propulsion control under power constraints, characterized in that The method comprises the following steps: establishing an electric propulsion power estimation model according to the composition of the electric propulsion system, wherein the electric propulsion system comprises an electric propulsion control unit, a pressure regulating module, a flow control module, a power processing unit and an electric thruster; establishing an electric propulsion control unit power estimation model and a power processing unit power estimation model according to the number of electric propulsion system operating points and the output power of the electric propulsion power estimation model, respectively; using the driving power output by the electric propulsion control unit power estimation model to provide input power for the pressure regulating module and the flow control module of the electric propulsion system, respectively; using the output power of the power processing unit power estimation model as the driving power of each electric thruster operating point; calculating the thruster power of each operating point according to the driving power of each electric thruster operating point; performing power comparison on the thruster power of each operating point to select available operating points and performing autonomous ignition according to the preset power supply and gas supply parameters of the available operating points; in the process of autonomous ignition, collecting 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; judging the electric propulsion input power of the whole device and the actual ignition power of the propulsion, and 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, then subsequent electric propulsion control is performed according to the actual ignition power of the propulsion, otherwise subsequent electric propulsion control of this autonomous ignition is performed according to the preset power supply and gas supply parameters of the autonomous ignition of the next gear.

2. The method according to claim 1, wherein the electric propulsion power estimation model is:

3. The method according to claim 2, wherein the electric propulsion control unit power estimation model is: P EPS = P EPCU输入 + P PPU输入 where P EPS is the total power of the electric propulsion, P EPCU输入 is the power of the electric propulsion control unit, P PPU输入 is the power of the power supply processing unit.

4. The method according to claim 3, wherein the power processing unit power estimation model is:

5. The method according to claim 4, wherein the method for calculating the actual ignition power of the electric propulsion is: P EPCU输入 = P EPCU静态 + (P PRM + P XFC ) / (η EPCU - η EPCULt ) where P EPCU静态 Pstatic is the static power of the electric propulsion control unit when the pressure regulation module and the flow control module are not working, PRM Pout is the driving power output to the pressure regulation module, XFC Pout is the driving power output to the flow control module, EPCU η is the power conversion coefficient of the electric propulsion control unit, EPCULt η is the power reduction coefficient of the electric propulsion control unit caused by the running time.

6. The method according to claim 5, wherein the method for calculating the actual ignition power of the electric propulsion is: measuring the bus voltage and bus current of the current power processing unit, and measuring the bus voltage and bus current of the current electric propulsion control unit; 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 ) / (η PPUj - η PPUjLt ) where P PPU静态 is the static power of the power processing unit, 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 power processing unit, α 电缆系数 is the conductor loss coefficient of the high-voltage cable, η PPUj is the power conversion coefficient of the power processing unit at the jth operating point, η PPUjLt is the power reduction coefficient of the power processing unit at the jth operating point caused by 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 by the thruster at the jth operating point due to performance degradation.

7. The method according to claim 6, wherein the method for calculating the thruster power of each operating point is: When the operating points of the electric propulsion system are not unique, the thruster rated power P ITj is determined for each operating point ITj额定 , P ITj补偿 , respectively, wherein: P ITj = P ITj额定 + P ITj补偿 When the power supply processing unit of the electric propulsion system supplies power for the thruster, the power loss of each working point is determined according to the working point position and the corresponding high-voltage cable conductor loss coefficient α 电缆系数 determined.

8. The method according to claim 1, wherein the method for selecting available operating points by performing power comparison on the thruster power of each operating point is:

9. The method according to claim 8, wherein the method for selecting available operating points by performing power comparison on the thruster power of each operating point is:

10. The method according to claim 1, wherein the preset power supply and gas supply parameters of the operating points are determined according to the power supply and gas supply parameters of each operating point installed in the electric propulsion control unit software. Using the resulting voltage data and current data to calculate the actual ignition power P 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 I EPCU母线电流 + U PPU母线电压 I PPU母线电流 wherein U EPCU母线电压 , I EPCU母线电流 is the bus voltage, bus current of the electric propulsion control unit, U PPU母线电压 , I PPU母线电流 is the bus voltage, bus current of the power supply processing unit. ​ ​ P EPS = P EPCU输入 + P PPU输入 = P EPCU静态 + (P PRM + P XFC ) / (η EPCU - η EPCULt ) + P PPU静态 + (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 ) where P EPS is the thruster power at each operating point. ​ According to the solar array capability budgeter of the power supply system, the power P that the electric propulsion can provide 整器电推输入 , by P 整器电推输入 Contrast with the actual ignition power P of the propulsion 电推实际点火功率 Determine the working point required for subsequent electric propulsion control. ​ ​ determining preset power margin P corresponding to each available working point 裕量i , judging P 整器电推输入 ≥(P EPSi +P 裕量i ), if current thruster power P 整器电推输入 satisfies the criterion, it is determined as an available working point, otherwise unavailable, P EPSi is the electric propulsion power estimation value of each working point. ​ ​ Pre-set power margin P 裕量i Determined according to the power margin parameter of each working point bound in the software of the electric propulsion control unit.

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