Energy state prediction method suitable for complex configuration remote sensing satellite

Abstract

The invention relates to an energy state prediction method suitable for a complex configuration remote sensing satellite, and belongs to the technical field of spaceflight. Reading an incident angle theta of the solar panel; calculating the projection condition of the star on the solar panel; judging whether each battery string is shielded or not; screening out a single string of batteries which are not shielded; calculating the output power P < total > of all the unshielded battery strings of the solar panel; counting the load power Pload of the whole satellite; comparing the P < total > with the P < load >; budgeting time T1 required for completing charging of the storage battery in a period from the current moment to the earth shadow period entering moment; budgeting the time T2 required by the storage battery to reach the maximum discharge depth, and taking the time T2 as the boundary of the current task execution capability; the T2 is judged, and whether the star attitude needs to be adjusted or not is determined according to the judgment result; the power generation capacity and the load power consumption condition of the on-satellite energy system are calculated in real time through the satellite attitude and the satellite configuration, the satellite energy flow states under different tasks are verified through ground calculation, and refined energy management is achieved.

Description

Technical Field

[0001] The invention belongs to the field of aerospace technology and relates to an energy state prediction method suitable for a remote sensing satellite with a complex configuration. Background Art

[0002] The spacecraft energy management problem is a classic resource allocation optimization problem. The short-term load distribution of the power supply and distribution system is an important part of the optimized operation of the power supply and distribution system. It means to maximize the use of electric energy under the premise of meeting the flight working mode requirements and various constraints. When the power supply capacity of the power supply and distribution system cannot meet the power demand of the normal working electrical load, it is necessary to automatically unload part of the electrical load to match the power supply of the power supply system, so as to ensure that the spacecraft completes the flight working mode or ensures the normal basic operation of the spacecraft in orbit.

[0003] For a spacecraft energy system, the amount of energy it can provide is limited. The main purpose of the power budget in the early stage of spacecraft design is to ensure that the energy provided by the energy system can meet the maximum energy demand of the spacecraft in various time periods during its in-orbit operation and to ensure the completion of the flight working mode. However, as the functions of spacecraft become increasingly complete, the configuration becomes more and more complex, and the postures become more and more diverse. During the in-orbit operation, due to the satellite adjusting its attitude during the mission and other reasons, the solar array is blocked by the celestial body, etc., resulting in the power supply capacity of the power supply and distribution system to decrease, or the load power consumption increases due to potential faults and exceeds the power budget. Therefore, the spacecraft is required to be able to judge the power supply capacity of the power supply and distribution subsystem and the power demand of the load in real time, and give the energy status expectation with the goal of completing the flight working mode to the maximum extent and ensuring the safety of the power supply and distribution system.

[0004] At present, the energy management method of remote sensing satellites mainly adopts the energy balance budget method. That is, according to the input conditions such as the energy system configuration, the on-board power load, and the main working mode of the satellite, the battery discharge depth, the number of cycles required for energy balance, and the working time limit of the satellite in different working modes are pre-calculated on the ground. This energy budget method has many disadvantages.

[0005] (1) There are limitations on applicable working modes. For remote sensing satellites, the working modes are complex and the satellite attitude changes frequently. Due to the diversity of working mode requirements, there are multiple combinations and variability of working modes and attitudes. Ground energy balance calculation can only give the envelope of a certain working mode, and cannot determine the energy status in a timely manner according to the combination and change of load working modes.

[0006] (2) There are deviations in calculation accuracy. The energy system parameters used in the budget are mainly based on the input conditions of ground simulation, test and experimental data, which are different from the on-orbit data. Therefore, a more conservative budget method is often adopted, which is calculated according to the worst conditions and reduces energy efficiency.

[0007] (3) It is impossible to monitor energy conditions in real time. When the solar panels are blocked and their power supply capacity is degraded, the results of the ground energy budget will not apply, and the satellite will not be able to achieve autonomous energy scheduling. If it is used according to the predetermined working mode, it will bring risks to the energy of the entire satellite. Summary of the invention

[0008] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art and propose an energy status prediction method suitable for remote sensing satellites with complex configurations, to calculate the power generation capacity and load power consumption of the on-board energy system in real time through satellite attitude and satellite configuration, to verify the satellite energy flow status under different tasks through ground calculations, and to achieve refined energy management.

[0009] The solution of the present invention is:

[0010] A method for predicting energy status of a remote sensing satellite with complex configuration, comprising:

[0011] Step 1: Read the incident angle θ of the solar panel through onboard telemetry data;

[0012] Step 2: Calculate the projection of the star on the solar sail panel; and determine whether each battery string is blocked according to the projection and the actual battery string layout of the solar sail panel;

[0013] Step 3: Filter out the unobstructed single string batteries; find the performance parameters to obtain the output power P of each single string battery i ; According to the output power P of the unshaded battery string i , calculate the output power P of all battery strings that are not blocked by the solar panels total ;

[0014] Step 4: Count the load power P of the entire satellite according to the current task execution status load ; for P total and P load Compare and decide whether to proceed to step five or step six or take no action;

[0015] Step 5: The star can complete the current task; estimate the time T1 required to charge the battery from the current moment to the moment of entering the Earth's shadow;

[0016] Step 6: Estimate the time T2 required for the battery to reach the maximum discharge depth as the boundary of the current task execution capability; proceed to step 7;

[0017] Step 7: Determine T2 and whether the star's attitude needs to be adjusted.

[0018] In the above-mentioned energy state prediction method applicable to remote sensing satellites with complex configurations, in step 2, the calculation method of the projection of the star on the solar sail is:

[0019] At the incident angle θ, the projection of the star on the solar sail is calculated based on the satellite configuration and attitude data through the three-dimensional space projection transformation algorithm.

[0020] In the above-mentioned energy state prediction method applicable to a remote sensing satellite with a complex configuration, the method for determining whether each battery string is blocked is:

[0021] The shielding area threshold is set to 5% of the battery string ratio; when the shielded area of ​​the battery string is less than 5%, it is determined that the battery string is not shielded; otherwise, it is determined that the battery is shielded.

[0022] In the above-mentioned energy state prediction method applicable to a remote sensing satellite with a complex configuration, in step 3, the output power P of all battery strings of the solar panels is total The calculation method is:

[0023]

[0024] In the formula, i is the serial number of the battery string;

[0025] n is the total number of battery strings.

[0026] In the above-mentioned energy state prediction method applicable to a remote sensing satellite with a complex configuration, in step 4, when the output power P total Greater than the load power P load When the output power P total Less than load power P load When the onboard battery is discharged, the process goes to step 6; when the output power P total Equal to load power P load When , do not take action.

[0027] In the above-mentioned energy status prediction method applicable to remote sensing satellites with complex configurations, in step five, after entering the earth's shadow period, all battery strings of the solar panels will be blocked, and the solar panels will not provide output power.

[0028] In the above-mentioned energy state prediction method applicable to a remote sensing satellite with a complex configuration, the time T1 required to complete battery charging is calculated as follows:

[0029]

[0030] In the formula, ΔQ is the current discharge capacity of the battery;

[0031] U is the bus voltage.

[0032] In the above-mentioned energy state prediction method applicable to a remote sensing satellite with a complex configuration, in step 6, the calculation method of the time T2 required for the battery to reach the maximum discharge depth is:

[0033]

[0034] In the formula, Q is the total power of the battery;

[0035] DOD is the maximum depth of discharge.

[0036] In the above-mentioned energy state prediction method applicable to remote sensing satellites with complex configurations, the maximum depth of discharge DOD is 65% of the total battery power.

[0037] In the above-mentioned energy state prediction method applicable to a remote sensing satellite with a complex configuration, in step 7, the specific method for judging T2 is:

[0038] Compare T2 with T0; when T2 is greater than or equal to T0, the star attitude needs to be adjusted; when T2 is less than T0, adjust the star attitude and increase the number of battery strings that are not blocked.

[0039] The beneficial effects of the present invention compared with the prior art are:

[0040] (1) The present invention uses remote sensing satellites with complex configurations, takes into account the shading of solar panels, combines the actual layout of solar cells, and considers the shading shadows of satellites on solar panels during different attitudes. The real-time output power of solar cells can be calculated in real time to perform on-board energy scheduling, prevent excessive use of energy in the event of energy system failure or increased power load, and improve the safety of satellite energy systems;

[0041] (2) The present invention uses real-time collected telemetry parameters to accurately calculate the battery pack capacity and predict the discharge depth. Compared with the existing ground energy balance budget method, it can judge the power supply capacity of the on-board energy system and the load power consumption status in real time, and can accurately calculate the energy balance status, avoiding the calculation deviation caused by inaccurate ground budget parameter collection;

[0042] (3) The present invention can predict the operating status of the satellite energy system and provide the maximum time envelope within which the subsequent mission can be performed. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is the energy status prediction flow chart of the present invention. DETAILED DESCRIPTION

[0044] The present invention will be further described below in conjunction with the embodiments.

[0045] The present invention provides an energy status prediction method suitable for remote sensing satellites with complex configurations. The power generation capacity and load power consumption of the on-board energy system are calculated in real time by satellite attitude and stellar configuration, and the satellite energy flow state under different tasks is verified by ground calculation, thereby realizing refined energy management, greatly improving the on-board energy utilization rate, and improving the satellite's mission execution capability. At the same time, according to the subsequent task injection situation, the on-board energy situation can be predicted in time, the boundary of task execution is given, and the safety and use margin of the energy system are guaranteed.

[0046] Energy status prediction methods applicable to remote sensing satellites with complex configurations, such as Figure 1 As shown, the specific steps include:

[0047] Step 1: Read the incident angle θ of the solar panel through onboard telemetry data.

[0048] Step 2: Calculate the projection of the star on the solar panel; and determine whether each battery string is blocked based on the projection and the actual layout of the battery strings on the solar panel.

[0049] The calculation method of the projection of the star on the solar sail is:

[0050] At the incident angle θ, the projection of the star on the solar sail is calculated based on the satellite configuration and attitude data through the three-dimensional space projection transformation algorithm.

[0051] The method for determining whether each battery string is blocked is as follows:

[0052] The shielding area threshold is set to 5% of the battery string ratio; when the shielded area of ​​the battery string is less than 5%, it is determined that the battery string is not shielded; otherwise, it is determined that the battery is shielded.

[0053] Step 3: Filter out the unobstructed single string batteries; find the performance parameters to obtain the output power P of each single string battery i ; According to the output power P of the unshaded battery string i , calculate the output power P of all battery strings that are not blocked by the solar panels total .

[0054] The output power P of all solar panels total The calculation method is:

[0055]

[0056] In the formula, i is the serial number of the battery string;

[0057] n is the total number of battery strings.

[0058] Step 4: Count the load power P of the entire satellite according to the current task execution status load ; for P total and P load Compare and decide whether to proceed to step five or step six or take no action.

[0059] Specifically:

[0060] When the output power P total Greater than the load power P load When the output power P total Less than load power P load When the onboard battery is discharged, the process goes to step 6; when the output power P total Equal to load power P load When , do not take action.

[0061] Step 5: The star can complete the current task; estimate the time T1 required to charge the battery from the current moment to the moment of entering the Earth's shadow.

[0062] After entering the Earth's shadow period, all the battery strings of the solar panels will be blocked, and the solar panels will not provide output power. At this time, the output power of the solar panels meets the current task, and only the time T1 required for the battery to be fully charged needs to be calculated.

[0063] The calculation method of the time T1 required to complete the battery charging is:

[0064]

[0065] In the formula, ΔQ is the current discharge capacity of the battery;

[0066] U is the bus voltage.

[0067] Step 6: Estimate the time T2 required for the battery to reach the maximum discharge depth as the boundary of the current task execution capability; proceed to step 7.

[0068] The calculation method of the time T2 required for the battery to reach the maximum discharge depth is:

[0069]

[0070] In the formula, Q is the total power of the battery;

[0071] DOD is the maximum depth of discharge.

[0072] The maximum depth of discharge DOD is 65% of the total battery capacity.

[0073] Step 7: Judge T2 and determine whether the star's attitude needs to be adjusted based on the judgment result.

[0074] The specific method for judging T2 is:

[0075] Compare T2 with T0; when T2 is greater than or equal to T0, the star attitude needs to be adjusted; when T2 is less than T0, adjust the star attitude and increase the number of battery strings that are not blocked.

[0076] The present invention reads the incident angle θ of the solar sail panel through on-board telemetry to obtain the current illumination condition on the solar sail panel, and calculates the shielding condition of the solar sail panel by the satellite body in combination with the satellite configuration and attitude data. In combination with the actual layout of the solar sail panel, the power generation power of different solar cell strings on the solar sail panel is calculated, and then the current power generation power of the entire satellite is calculated. According to the current satellite working mode and mission execution, the load state of the entire satellite is counted, and the power balance calculation of the energy of the entire satellite is performed in combination with the discharge condition of the satellite battery group. If the satellite energy system is in a state of oversupply, that is, the power generation power is greater than the load power, the time required for the satellite to reach energy balance is calculated; if the satellite energy system is in a state of undersupply, that is, the power generation power is less than the load power, the boundary time that the satellite can perform the current mission is calculated.

[0077] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may 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 modifications, equivalent changes and modifications 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 shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for predicting energy status of a remote sensing satellite with a complex configuration, characterized in that: include: Step 1: Read the incident angle θ of the solar panel through onboard telemetry data; Step 2: Calculate the projection of the star on the solar sail panel; and determine whether each battery string is blocked according to the projection and the actual battery string layout of the solar sail panel; Step 3: Filter out the single string of batteries that are not blocked; Find the performance parameters to obtain the output power P of each single string battery i ; According to the output power P of the unshaded battery string i , calculate the output power P of all battery strings that are not blocked by the solar panels total ; Step 4: Count the load power P of the entire satellite according to the current task execution status load ; for P total and P load Compare and decide whether to proceed to step five or step six or take no action; Step 5: The star can complete the current task; estimate the time T1 required to charge the battery from the current moment to the moment of entering the Earth's shadow; Step 6: Estimate the time T2 required for the battery to reach the maximum discharge depth as the boundary of the current task execution capability; proceed to step 7; Step 7: Determine T2 and whether the star's attitude needs to be adjusted.

2. The energy state prediction method applicable to a remote sensing satellite with a complex configuration according to claim 1, characterized in that: In step 2, the calculation method of the projection of the star on the solar sail is: At the incident angle θ, the projection of the star on the solar sail is calculated based on the satellite configuration and attitude data through the three-dimensional space projection transformation algorithm.

3. The energy status prediction method applicable to a remote sensing satellite with a complex configuration according to claim 2, characterized in that: The method for determining whether each battery string is blocked is: The shielding area threshold is set to 5% of the battery string ratio; when the shielded area of ​​the battery string is less than 5%, it is determined that the battery string is not shielded; otherwise, it is determined that the battery is shielded.

4. The energy state prediction method applicable to a remote sensing satellite with a complex configuration according to claim 3 is characterized in that: In step 3, the output power P of all battery strings of the solar panel total The calculation method is: Where i is the serial number of the battery string; n is the total number of battery strings.

5. The energy status prediction method applicable to a remote sensing satellite with a complex configuration according to claim 1, characterized in that: In step 4, when the output power P total Greater than the load power P load When the output power P total Less than load power P load When the onboard battery is discharged, the process goes to step 6; when the output power P total Equal to load power P load When , do not take action.

6. The energy status prediction method applicable to a remote sensing satellite with a complex configuration according to claim 5, characterized in that: In the step 5, after entering the earth's shadow period, all the battery strings of the solar panel will be blocked, and the solar panel will not provide output power.

7. The energy status prediction method applicable to a remote sensing satellite with a complex configuration according to claim 6, characterized in that: The calculation method of the time T1 required to complete the battery charging is: In the formula, ΔQ is the current discharge capacity of the battery; U is the bus voltage.

8. The energy status prediction method applicable to a remote sensing satellite with a complex configuration according to claim 7, characterized in that: In step 6, the time T2 required for the battery to reach the maximum discharge depth is calculated as follows: In the formula, Q is the total power of the battery; DOD is the maximum depth of discharge.

9. The energy status prediction method applicable to a remote sensing satellite with a complex configuration according to claim 8, characterized in that: The maximum depth of discharge DOD is 65% of the total battery capacity.

10. The energy status prediction method applicable to a remote sensing satellite with a complex configuration according to claim 9, characterized in that: In step 7, the specific method for judging T2 is: Compare T2 with T0; when T2 is greater than or equal to T0, the star attitude needs to be adjusted; when T2 is less than T0, adjust the star attitude and increase the number of battery strings that are not blocked.

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