Methods to reduce the failure probability of solar cell array shunts for low-Earth orbit satellites

Abstract

This invention discloses a method for reducing the failure probability of solar array shunts in low-Earth orbit (LEO) satellites. The method determines the shunt thermal power boundary by jointly using a shunt current threshold and a shunt temperature threshold. It then clusters the set of satellites to be monitored, identifies the set of satellites exceeding the shunt thermal power boundary, and pre-emptively manipulates the solar array bias of these satellites. This method effectively reduces the probability of shunt failure in LEO satellites.

Description

Technical Field

[0001] This invention belongs to the field of spacecraft on-orbit control technology, specifically relating to a method for reducing the failure probability of a solar cell array shunt for a low-orbit satellite. Background Technology

[0002] The shunt is a crucial regulating module in a solar array, stabilizing the output voltage by diverting excess current from the solar cells. During long-term on-orbit operation, the shunt current threshold is typically used as an indicator of overload and as a basis for bias control of the solar array. However, in practical applications, shunt current failures can occur even when the shunt current does not exceed the threshold, leading to shunt malfunctions. Analysis of existing failure cases reveals that shunt temperature is also a significant factor causing shunt failures. Based on the analysis of on-orbit telemetry data regarding the shunt's operating status, temperature, and current, a method for reducing the failure probability of shunts in low-Earth orbit satellite solar arrays is proposed. Summary of the Invention

[0003] The purpose of this invention is to provide a method for reducing the failure probability of a shunt in a low-Earth orbit satellite solar array, which solves the problem of high failure probability of the shunt caused by using only the shunt current threshold as the bias control threshold of the solar array.

[0004] The technical solution adopted in this invention is: a method for reducing the failure probability of a solar cell array shunt for low-orbit satellites, wherein the shunt current threshold and the shunt temperature threshold are jointly used to determine the thermal power boundary of the shunt, the set of satellites to be monitored is clustered to obtain the set of satellites that exceed the thermal power boundary of the shunt, and the solar cell array bias is pre-emptively manipulated for the satellites in the set.

[0005] The present invention is further characterized by including the following steps:

[0006] Step 1: Establish a thermal power model for the solar cell array shunt of a low-orbit satellite;

[0007] Step 2: Obtain the set of satellites to be observed, S = {s1, s2, ..., s} m}, where m represents the number of satellites in the set, s i Let i represent any satellite in the set, 1≤i≤m, and obtain the shunt current telemetry value and temperature telemetry value of m satellites at time t.

[0008] Step 3: Set the current threshold and temperature threshold of the solar array shunt, input the thermal power model of the solar array shunt obtained in Step 1, and obtain the thermal power boundary curve of the solar array shunt.

[0009] Step 4: Perform corresponding solar array bias control on the subset of satellites in the satellite set S obtained in Step 2 that exceed the thermal power boundary curve of the solar array shunt obtained in Step 3.

[0010] The thermal power model of the low-orbit satellite solar cell array shunt established in step 1 is as follows: Where T is the telemetry value of the solar array shunt temperature, I is the telemetry value of the solar array shunt current, T0 is the solar array shunt temperature threshold, and I0 is the solar array shunt current threshold.

[0011] In step 2, time t refers to a specific moment or time period. If it is a time period, the characteristic values ​​of the current telemetry and temperature telemetry values ​​of the shunts of m satellites during time period t are obtained. The characteristic value is the average or the maximum value.

[0012] In step 4, the subset of satellites above the curve is S' = {s1, s2, ..., s}. n}, where n≥0 is the number of satellites above the curve; if n>0, then the corresponding solar cell array bias control is performed on the satellites in S', otherwise the solar cell array bias control is not required on the satellites in S.

[0013] The beneficial effects of the present invention are as follows: The method for reducing the failure probability of solar cell array shunts for low-orbit satellites of the present invention determines the thermal power boundary of the shunt by jointly determining the shunt current threshold and the shunt temperature threshold, clusters the set of satellites to be monitored, obtains the set of satellites exceeding the thermal power boundary, and performs solar cell array bias control in advance, thereby effectively reducing the probability of failure of the solar cell array shunt. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the method for reducing the failure probability of a solar cell array shunt for a low-orbit satellite according to the present invention;

[0015] Figure 2 This is a schematic diagram showing the distribution of the average shunt current and average shunt temperature of each satellite in the set of satellites to be monitored, obtained in step 2 of this embodiment of the invention.

[0016] Figure 3 This is a schematic diagram of the thermal power boundary curve of the solar cell array shunt obtained in step 3 of the present invention.

[0017] Figure 4 This is a schematic diagram of the change in solar cell array current after biasing the solar cell array in an embodiment of the present invention;

[0018] Figure 5 This is a schematic diagram of the change in the shunt current of the solar cell array after biasing the solar cell array in an embodiment of the present invention;

[0019] Figure 6This is a schematic diagram of the temperature change of the solar cell array shunt after the solar cell array is biased in an embodiment of the present invention. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0021] This invention provides a method for reducing the failure probability of a shunt in a low-Earth orbit satellite solar array. The method determines the shunt thermal power boundary by jointly using a shunt current threshold and a shunt temperature threshold. It then clusters the set of satellites to be monitored, identifies the set of satellites exceeding the shunt thermal power boundary, and pre-emptively manipulates the solar array bias of these satellites. Figure 1 As shown, it includes the following steps:

[0022] Step 1: Establish the thermal power model of the low-Earth orbit satellite solar cell array shunt as TPM_SPD: Where T is the telemetry value of the solar array shunt temperature, I is the telemetry value of the solar array shunt current, T0 is the solar array shunt temperature threshold, and I0 is the solar array shunt current threshold.

[0023] Step 2: Obtain the set of satellites to be monitored, and the shunt current and temperature values ​​during the monitoring period. This includes the following steps:

[0024] Step 2.1: Obtain the satellite information to be monitored, S = {s1, s2, ..., s} m}, where S represents the set of satellites to be monitored, with a total of m satellites, m = 34, s i (1≤i≤m) represents the identifier of any satellite;

[0025] Step 2.2: Set the time t for acquiring telemetry data, where t is a time window from the start of orbit insertion to 30 days after insertion. i The orbital insertion time is t i0 , then t i =[t i0 , t i0+30 ];

[0026] Step 2.3: Obtain satellite s i At time t i The average current and average temperature of the shunt in the solar cell array, and the current and temperature values ​​of the shunt in the solar cell array of satellite collection S are as follows: Figure 2 As shown.

[0027] Step 3: Set the current and temperature thresholds for the low-Earth orbit satellite solar array shunt according to the control requirements of the low-Earth orbit satellite, and run the thermal power model TPM_SPD. This includes the following steps:

[0028] Step 3.1: Set the current threshold I0 of the low-Earth orbit satellite solar cell array shunt to 7.5A;

[0029] Step 3.2: Set the temperature threshold T0 of the low-orbit satellite solar cell array shunt to 40.0℃;

[0030] Step 3.3: Run the thermal power model TPM_SPD based on I0 and T0 to obtain the thermal power boundary curve, as shown below. Figure 3 As shown.

[0031] Step 4: Obtain the subset of satellites above the thermal power boundary curve based on the model results, and perform corresponding solar cell array bias control on the satellites in the subset. This includes the following steps:

[0032] Step 4.1: Based on the thermal power boundary curve, determine the set of satellites S' = {s1, s2, ..., s} located above the boundary of the thermal power curve. n}, where n = 6 is the number of satellites in set S';

[0033] Step 4.2: Perform solar array bias control on the 6 satellites in S'. After bias control is performed on one of the satellites in S', the telemetry value of the solar array output current is as follows: Figure 4 As shown, the peak output current of the solar array decreased by approximately 5A; correspondingly, the telemetry value of the shunt current is as follows: Figure 5 As shown, the peak current of the shunt decreased by approximately 1.8A; the telemetry value of the shunt temperature is as follows. Figure 6 As shown, the temperature distribution range shifted significantly downwards, with the peak value decreasing by approximately 7°C.

[0034] Through the above-described method, the method for reducing the failure probability of shunts in low-Earth orbit (LEO) satellite solar arrays of the present invention overcomes the problem that shunt failures occur during long-term management of LEO satellites when the shunt current does not exceed the threshold, which is a problem that arises when the shunt current is used as the bias control threshold solely for LEO satellite solar array shunts. Applying this method to the long-term on-orbit management of LEO satellite solar arrays effectively reduces the probability of shunt failures.

Claims

1. A method for reducing the failure probability of a solar cell array shunt for low-Earth orbit satellites, characterized in that, The shunt thermal power boundary is determined by combining the shunt current threshold and the shunt temperature threshold. The satellite set to be monitored is clustered to obtain the set of satellites that exceed the shunt thermal power boundary. The solar cell array bias is then controlled in advance for the satellites in the set.

2. The method for reducing the failure probability of a low-Earth orbit satellite solar cell array shunt as described in claim 1, characterized in that, Includes the following steps: Step 1: Establish a thermal power model for the solar cell array shunt of a low-orbit satellite; Step 2: Obtain the set of satellites to be observed S ={ , ,…, },in m Indicates the number of satellites in the set. Represents any satellite in the set. , obtain m satellite t The time-based telemetry values ​​of shunt current and temperature; Step 3: Set the current threshold and temperature threshold of the solar array shunt, input the thermal power model of the solar array shunt obtained in Step 1, and obtain the thermal power boundary curve of the solar array shunt. Step 4: Process the satellite set obtained in Step 2 S For satellite subsets that exceed the thermal power boundary curve of the solar cell array shunt obtained in step 3, corresponding solar cell array bias control is performed.

3. The method for reducing the failure probability of a low-Earth orbit satellite solar array shunt as described in claim 2, characterized in that, The thermal power model of the low-orbit satellite solar cell array shunt established in step 1 is as follows: ,in T This is a remote temperature measurement of the solar cell array shunt. I This is the telemetry value of the current in the solar cell array shunt. T 0 represents the temperature threshold of the solar cell array shunt. I 0 represents the current threshold of the solar cell array shunt.

4. The method for reducing the failure probability of a low-Earth orbit satellite solar array shunt as described in claim 2, characterized in that, In step 2 t The time is a specific moment or period of time. If it is a period of time, then retrieve... m satellite t The characteristic values ​​of the time-period shunt current telemetry value and temperature telemetry value are the average value or the maximum value.

5. The method for reducing the failure probability of a low-Earth orbit satellite solar cell array shunt as described in claim 2, characterized in that, In step 4, the subset of satellites above the curve is... S '={ , ,…, },in n ≥0 represents the number of satellites above the curve; if n >0, then for S The satellites in the ' ' need to perform corresponding solar array bias control; otherwise, no further control is required. S The satellites in the system are used for solar cell array bias control.

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