A complex continuous multi-working condition flicker protection strategy

Abstract

This invention proposes a scintillation protection strategy for complex, continuous, multi-condition operation, belonging to the field of spacecraft electric propulsion control technology. It addresses the problem in existing satellite ion electric propulsion systems where the gate preprocessing level switching process and the scintillation protection process overlap in time, leading to conflicting control commands, timing errors, and even abnormal PPU shutdowns due to concurrent conflicts. The strategy includes: during condition switching, setting the "scintillation protection function enable flag" to a disabled state; reading the scintillation protection process status word to determine if it is "in execution" or "idle"; if "in execution," the system enters a waiting loop, waiting for it to become "idle"; when "idle," the system executes the condition switching process; after the condition switching is completed, the "scintillation protection function enable flag" is restored.

Description

Technical Field

[0001] This invention belongs to the field of spacecraft electric propulsion control technology, and in particular relates to a scintillation protection strategy under complex continuous multi-condition conditions. Background Technology

[0002] Satellite electric propulsion systems typically consist of an ion thruster, a power processing unit (PPU), a propellant supply unit, and a control interface. During on-orbit operation, the electric propulsion software performs autonomous closed-loop control upon receiving preprocessing or ignition commands. To improve thruster operational stability, multiple preprocessing conditions are usually set after grid loading, and the system automatically switches to the next condition after each condition reaches its rated duration. Simultaneously, to address potential on-orbit anomalies such as sparking in the ion thruster, corresponding flashover protection procedures must be designed to prevent the thruster and PPU from being subjected to prolonged flashover current surges.

[0003] However, on-orbit ignition of the ion thruster is random and can occur at any time after the grid is loaded. If the trigger time of the scintillation protection coincides with the gear switching time of a certain pretreatment condition, the gear switching process and the protection process may be executed interchangeably. Both processes may access the same control object, such as beam closed-loop control, automatic grid extraction control, and grid module switching control, which can lead to contradictory control commands, disordered status words, and even abnormal shutdown of the PPU. This will cause control timing disorder and inconsistent status, seriously affecting the safe operation of the ion thruster under complex, continuous, and multi-condition conditions.

[0004] It should be noted that the flash protection mechanism set up in the satellite ion electric propulsion system for continuous flashing of the thruster is itself an existing control logic. Its main function is to activate the protection process when multiple consecutive short flashes of the thruster are detected, so as to protect the PPU and the ion thruster.

[0005] Therefore, how to provide a protection strategy for ion electric propulsion systems under complex, continuous, and multi-operating conditions that can both maintain the effectiveness of scintillation protection and avoid concurrent conflicts with other automated processes has become an urgent technical problem to be solved. Summary of the Invention

[0006] In view of this, the present invention aims to propose a scintillation protection strategy under complex continuous multi-condition conditions to solve the problem that when the gate preprocessing level switching process and the scintillation protection process overlap in time in the existing satellite ion electric propulsion system, the concurrent conflict leads to contradictory control commands, timing disorder, and even abnormal shutdown of the PPU.

[0007] To achieve the above objectives, the present invention adopts the following technical solution to provide a flicker protection strategy under complex continuous multi-condition working conditions, comprising the following steps: S1. When switching operating conditions, the system sets the "flicker protection function enable flag" to the disabled state; S2. Read the status word of the flashing protection process and determine whether it is "in execution" or "idle"; S3. If it is "in execution", the system enters a waiting loop, waiting for it to become "idle"; S4. When the system is "idle", it executes the switching process. S5. After the operating condition switch is completed, restore the "flicker protection function enable flag".

[0008] Furthermore, the switching condition described in S1 is: after the system determines that the current gate preprocessing condition has reached the rated duration, it needs to switch to the next condition.

[0009] Furthermore, in S2, the flashing protection function is in operation, and the gear shifting process does not issue a gear shifting control command, but enters a waiting loop.

[0010] Furthermore, the waiting loop described in S3 is: periodically reading the flash protection process status word.

[0011] Furthermore, the period is 32ms.

[0012] Furthermore, the flashing protection function is disabled during the execution of the switching process described in S4 to avoid entering a new protection process.

[0013] Furthermore, after restoring the "flicker protection function enable flag" as described in S5, the flicker protection function will be reinstated.

[0014] Furthermore, it can be applied to satellite ion electric propulsion systems.

[0015] Beneficial effects: 1. Eliminate concurrent conflicts in electric propulsion software: This invention effectively avoids the problem of cross-cycle execution of mutually exclusive commands such as "beam closed-loop prohibition" and "beam closed-loop enable" by prohibiting flashing protection before gear switching, waiting for the protection process to complete before switching, and maintaining a mutual exclusion mechanism during switching.

[0016] 2. Ensure the consistency of control timing of electric propulsion software; This invention transforms the originally potentially concurrent protection process and gear switching process into a serial execution process constrained by status words, which is beneficial to ensure the consistency of the state of controlled objects such as PPU, grid module and ion thruster.

[0017] 3. Reduce the risk of abnormal PPU shutdown; By avoiding concurrent timing conflicts, this invention can effectively reduce the risk of PPU protective shutdown, accidental shutdown or abnormal shutdown caused by control sequence disorder.

[0018] 4. Improve the reliability of operation under complex multi-condition conditions; This invention is particularly suitable for ion electric propulsion systems with multiple operating points and complex pretreatment conditions, and has strong engineering applicability in scenarios with continuous switching of multiple operating conditions.

[0019] 5. Easy to implement in engineering: This invention mainly relies on software status words, enable flags and waiting loop mechanisms, without requiring a significant increase in hardware resources, and is suitable for upgrading and deploying on the basis of existing electric propulsion control software. Attached Figure Description

[0020] Figure 1 This is a flowchart of the present invention; Figure 2 This is a flowchart of the flicker protection strategy judgment of the present invention. Detailed Implementation

[0021] Referring to the accompanying drawings, this embodiment provides a flicker protection strategy under complex, continuous, and multi-condition working conditions.

[0022] The system employs the following flicker protection triggering mechanism: When N consecutive ignitions are detected, and the duration of each ignition is less than the preset time threshold T1, the flashing protection process is initiated. N is 5 by default and can be modified through remote control parameters, with a reference range of 1 to 16. T1 is 1 minute by default.

[0023] When the number of times the flashing protection process is executed (i) is greater than or equal to the preset upper limit (M), the ignition shutdown fault flag is set to 1, and the system enters safe mode. M is 6 by default and can be modified through remote control parameters. The reference range is 1 to 16.

[0024] If the number of flashing protection cycles does not increase within the duration T2, the number of flashing protection cycles will be reset to zero. T2 is 15 minutes by default and can be modified via remote control parameters. The reference range is 5 to 60 minutes.

[0025] The key improvement of this invention lies in introducing the following mechanism in the gate preprocessing level switching process: Step 1: Set flashing protection mode when shifting gears When the system determines that the current gate preprocessing condition has reached the rated duration and needs to switch to the next condition, the system first sets the "flicker protection function enable flag" to the disabled state to avoid the system repeatedly triggering the flicker protection process when it is about to perform a gear switch.

[0026] Step 2: Check the flashing protection execution status Read the status word of the blink protection process. If "blink protection process status word = executing" is detected, it means that the blink protection process is currently being executed.

[0027] Step 3: Wait for the flicker protection process to finish. When the status word is "in execution", the gear shifting process does not directly issue a gear shifting control command, but enters a waiting loop; in the waiting loop, the flashing protection process status word is periodically checked until the status word becomes "idle", and the detection period is 32ms.

[0028] Step 4: Execute the gear shifting procedure after idle period. The switching process from the current preprocessing condition to the next condition is executed only when the flashing protection process status word is 0, i.e. the process is idle; and the flashing protection function is kept disabled during the gear switching execution to avoid entering a new protection process.

[0029] Step 5: Restore protection function after gear shifting is complete. After the gear shifting process is completed and the system status is stable, restore the flash protection function enable flag to enable the system to regain its flash protection capability.

[0030] Example A satellite's ion electric propulsion system has 20 operating points with different power levels. During the gate pretreatment stage, six pretreatment conditions are executed sequentially from low to high power. Each pretreatment condition automatically switches to the next condition after reaching its corresponding rated duration. Simultaneously, the system also features a PPU flashover protection function; when five consecutive firings are detected, each with a firing duration of less than 1 minute, the PPU flashover protection sequence is triggered.

[0031] In this embodiment, it is assumed that the system is currently operating in the k-th (1≤k≤5) gate preprocessing condition, and the mode switching time has been reached. When the control program prepares to switch from the k-th preprocessing condition to the (k+1)-th preprocessing condition, if the flicker protection trigger condition is also met at this time, under the existing control method, the gate preprocessing mode switching process and the PPU flicker protection process will be executed alternately in adjacent control cycles. Specifically, in the previous control cycle, the PPU flicker protection process has output the "screen beam current automatic extraction off" control command; while in the next control cycle, the gate preprocessing mode switching process outputs the "beam current closed-loop control enable" control command, so that the PPU receives conflicting control commands in two consecutive control cycles, thereby causing control timing disorder, which may lead to abnormal PPU shutdown in severe cases.

[0032] To address the aforementioned operating conditions, this invention introduces a flicker protection interlock control strategy during the gate preprocessing level switching process. Specifically, when the system detects that the k-th preprocessing condition meets the switching conditions, it does not immediately execute the level switching. Instead, it first disables the flicker protection function to prevent re-entry into the PPU flicker protection process within the level switching window. Then, it reads the "PPU flicker protection sequence execution status." When the execution status is detected as "in execution," it indicates that the PPU flicker protection process has not yet ended. At this time, the level switching program remains in a waiting state and does not execute the switch from the k-th preprocessing condition to the (k+1)-th preprocessing condition. Only when the execution status is detected as "idle" is the gate preprocessing level switching process initiated, and the corresponding control parameters are switched to the next preprocessing condition. Throughout the entire level switching execution, the flicker protection function remains disabled until the level switching is completed, at which point the flicker protection function is restored.

[0033] In the scenario described above, where "the k-th preprocessing condition reaches the switching time and simultaneously meets the flash protection triggering condition" as described in this embodiment, the PPU flash protection process and the gate preprocessing level switching process no longer execute concurrently. Instead, they run sequentially in the order of "flash protection process completed first, followed by level switching process." This avoids the problem of conflicting commands such as "screen beam current automatic extraction off" and "beam current closed-loop control enable" being issued continuously in adjacent control cycles, ensuring the consistency of PPU control timing and improving the control reliability and operational safety of the satellite ion electric propulsion system under complex continuous multi-condition operation.

[0034] The embodiments of the present invention disclosed above are merely illustrative of the invention. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A flicker protection strategy under complex continuous multi-conditions, characterized in that, Includes the following steps: S1. When switching operating conditions, the system will set the "flicker protection function enable flag" to the disabled state; S2. Read the status word of the flashing protection process and determine whether it is "in execution" or "idle"; S3. If it is "in execution", the system enters a waiting loop, waiting for it to become "idle"; S4. When the system is "idle", it executes the switching process. S5. After the operating condition switch is completed, restore the "flicker protection function enable flag".

2. The flicker protection strategy for complex continuous multi- operating conditions according to claim 1, characterized in that: The switching condition described in S1 is: after the system determines that the current gate preprocessing condition has reached the rated duration, it needs to switch to the next condition.

3. The flicker protection strategy for complex continuous multiple operating conditions of claim 1, wherein: In S2, the flashing protection function is in operation, and the gear shifting process does not issue gear shifting control commands, but enters a waiting loop.

4. The flicker protection strategy for complex continuous multi- operating conditions according to claim 1 or 3, characterized in that: The waiting loop described in S3 is: periodically reading the flash protection process status word.

5. The flicker protection strategy for complex continuous multi- operating conditions according to claim 4, characterized in that: The period is 32ms.

6. The flicker protection strategy for complex continuous multiple operating conditions of claim 1, wherein: During the execution of the switching process described in S4, the flashing protection function is disabled to prevent entering a new protection process.

7. The flicker protection strategy for complex continuous multi- operating conditions according to claim 1, characterized in that: After restoring the "flicker protection function enable flag" as described in S5, the flicker protection function will be reinstated.

8. The flicker protection strategy for complex continuous multiple operating conditions of claim 1, wherein: It is used in satellite ion electric propulsion systems.

Images