A distributed spacecraft power system standard interface unit

Abstract

This invention discloses a standard interface unit for a distributed spacecraft power system, relating to the technical field of control methods for scalable and reconfigurable distributed power systems. The standard interface unit serves as the interface between the power generation / storage units and the DC bus in the distributed power system, and simultaneously features hot-swappable operation and rapid fault protection. The standard interface unit includes an input interface module, a bidirectional solid-state switch module, a control unit module, an auxiliary power module, a CAN communication module, an isolation drive module, a signal acquisition module, a current threshold protection module, a hot-swappable module, an indicator module, and an output interface module. This invention solves the problems of hot-swappable operation and rapid protection of distributed units in power systems of spacecraft undergoing on-orbit servicing through a standardized and universal electrical interface. Its application is suitable for scalable, reconfigurable, and high-power distributed power systems for spacecraft undergoing on-orbit servicing and maintenance.

Description

Technical Field

[0001] This invention relates to standard interface units for distributed spacecraft power systems, and more particularly to the technical field of control methods for scalable and reconfigurable distributed power systems. Background Technology

[0002] Currently, spacecraft power systems are generally not capable of on-orbit repair, replacement, or reconfiguration. However, with the rapid development of aerospace technology, especially for spacecraft undergoing on-orbit servicing and maintenance, there is a growing need for on-orbit repair and replacement of consumable and vulnerable modules such as solar panels and battery packs. Solar panels, battery packs, and controllers can be upgraded on-orbit by improving their power generation, energy storage, and regulation capabilities. Systems can be reconfigured and their power capacity expanded by replacing or adding modules, enabling them to adapt to power demands from stable loads and short-duration high-power pulse loads, possessing flexible load-bearing capabilities. On-orbit servicing and maintenance spacecraft have an urgent need for on-orbit repair, replacement, refueling, upgrades, reconfiguration, expansion, and flexible load-bearing capabilities.

[0003] Space-based distributed power systems, characterized by modularity, standardization, arbitrary combination and reconfigurability, high reliability, and good safety, are an inevitable outcome to meet future needs for on-orbit service, flexible mission customization, rapid development, rapid production, rapid launch, on-orbit performance upgrades, extended lifespan, and mission expansion. For space-based reconfigurable distributed power systems, achieving flexible access to distributed generation and energy storage units is particularly important. In traditional distributed power systems, the access of distributed generation and energy storage units typically uses solid-state power switches. Traditional solid-state power switches are mainly used in AC / DC intelligent power distribution systems in aviation and ships to achieve automatic load management, remote control, status detection, fault prediction and handling, and fault tolerance. However, traditional solid-state power switches cannot achieve hot-swapping, meaning that inserting or removing modules into or from the power system without shutting down the system or disconnecting the power supply will cause voltage and current surges on the power bus, affecting the normal operation of the system. Hot-swapping capability can improve system reliability, rapid maintainability, redundancy, and timely recovery from disasters. Therefore, a universal standard power interface with hot-swapping functionality is needed to meet the interface requirements for replacement, upgrades, reconfiguration, and power expansion. Summary of the Invention

[0004] The technical problem solved by this invention is that the traditional power system's access methods for power generation and energy storage units can no longer meet the requirements of flexible access, flexible expansion, and rapid protection of distributed reconfigurable space power systems, which are needed for on-orbit service and maintenance, large space stations, deep space probes, and other spacecraft applications that require repairability, replacement, upgradeability, reconfigurability, expansion, and flexible support.

[0005] The objective of this invention is achieved through the following technical solutions:

[0006] This invention proposes a standard interface unit for distributed spacecraft power systems, applicable to distributed reconfigurable power systems in spacecraft. Through a standardized and universal electrical interface, it solves the problems of distributed spacecraft power generation and storage units being unable to be hot-swapped or quickly protected for on-orbit service and maintenance. Its application scenarios are suitable for scalable, reconfigurable, and high-power distributed spacecraft power systems.

[0007] The standard interface unit serves as the interface between the power generation and energy storage units and the DC bus in a distributed power system, and also features hot-swappable functionality and rapid fault protection.

[0008] The standard interface unit includes an input interface module, a bidirectional solid-state switch module, a control unit module, an auxiliary power supply module, a CAN communication module, an isolation drive module, a signal acquisition module, a current threshold protection module, a hot-swappable module, an indicator module, and an output interface module, etc.

[0009] The input interface module employs a long-short pin structure to enable hot-swapping. Hot-swapping protection utilizes both hardware and software redundancy to prevent circuit damage in the event of a single protection failure. The system is only activated when the connector is detected to be fully inserted, increasing system reliability and safety. A bidirectional solid-state switch module enables bidirectional power flow control and protection. The control unit module's protection parameters allow for software-defined protection thresholds and strategies, implementing inverse time-limit protection, fast short-circuit protection, and power switch control functions. This invention solves the problem of distributed units in power systems of on-orbit servicing spacecraft being unable to be hot-swapped or rapidly protected through a standardized, universal electrical interface. Its application scenarios are suitable for scalable, reconfigurable, high-power distributed power systems in on-orbit servicing and maintenance applications.

[0010] The main features of this invention are:

[0011] 1. The standard interface unit includes an input interface module, a bidirectional solid-state switch module, a control unit module, an auxiliary power supply module, a CAN communication module, an isolation drive module, a signal acquisition module, a current threshold protection module, a hot-swap module, an indicator module, and an output interface module. The standard interface unit also features hot-swap capability and rapid protection.

[0012] 2. The input interface module is responsible for connecting the standard interface unit to the DC bus and communication bus of the distributed system. The bidirectional solid-state switch module is responsible for turning the main power input and output interfaces on or off. The control unit module is responsible for data acquisition, digital-to-analog conversion, system fault diagnosis, solid-state switch control, communication with the host computer, and software protection. The auxiliary power supply module converts the input voltage to the low voltage used by various modules in the system to power the entire system. The CAN communication module enables data and command communication between the standard interface unit and the host computer. The isolation drive module uses optocoupler isolation drive; the PWM wave control signal generated by the CPU drives the solid-state switch through the isolation drive module, ensuring electrical isolation between the control circuit and the drive signal. The signal acquisition module includes main circuit input / output voltage, current, and temperature acquisition circuits, inputting the acquired signals to the CPU's digital-to-analog conversion interface for digital-to-analog conversion. The current threshold protection module implements current threshold protection in hardware, including blocking the power transistor drive optocoupler input and blocking the PWM output by a fault signal driven by the DSP on-chip comparator. The hot-swap and indicator module enables hot-swapping. Utilizing the different lengths of the connector pins, it transmits information to the CPU regarding whether the connector is fully inserted, preventing system damage caused by starting the system with an incompletely inserted connector. Different colored LEDs indicate three connector states: connected, on / off, and fault protection. The output interface module handles connections between standard interface units and distributed power modules or loads.

[0013] 3. The hot-swap module features both hardware and software hot-swap protection. The system only activates when a fully inserted connector is detected, preventing circuit damage in the event of a single protection failure and increasing system reliability and safety. The hot-swap SWAP_IN signal is output to both the CPU for software protection and the driver circuit for hardware protection.

[0014] The SWAP pin is designed to be short. When the standard interface is connected to the system, due to the short length of the SWAP pin, the SWAP pin is floating, the transistor is turned on, and SWAP_IN is pulled low. SWAP_IN is connected to a GPIO port of the CPU. When the CPU detects that this GPIO port is low, it does not start the system. When the connector is fully inserted, the SWAP ground is pulled low, the transistor is turned off, and SWAP_IN is pulled high by the pull-up resistor. When the CPU detects that this GPIO port is high, it starts the system. This is a hot-swappable software protection scheme.

[0015] The SWAP_IN signal is also connected to the driver circuit. When the connector is not fully inserted, SWAP_IN is low, pulling the positive input port of the optocoupler low. At this time, regardless of the PWM level, the optocoupler will not conduct. When the connector is fully inserted, SWAP_IN becomes high, the diode is reverse-biased and cut off, and the positive input port of the optocoupler is at the same level as the PWM wave output by the CPU. That is, the optocoupler conducts when the PWM is high and turns off when the PWM is low. This is the hot-swap hardware protection scheme.

[0016] 4. The control unit module allows for software-defined protection thresholds and strategies. The control unit module hardware includes an I / O submodule, a PWM submodule, a comparator submodule, an ADC conversion submodule, and a CAN communication submodule. The control unit module software includes a main program, a timer interrupt program, and a PWM interrupt program. The main program primarily implements power-on initialization and important data recovery functions; the timer interrupt primarily implements time recording, telemetry acquisition, parameter uploading, bus communication, and health diagnostics functions; the PWM interrupt primarily implements inverse time limit protection, short-circuit protection, and power switch control functions.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. The standard interface unit features both hot-swappable and fast fault protection. The main power switch section employs a bidirectional solid-state switch composed of three power switching transistors, enabling bidirectional power flow control.

[0019] 2. The electrical connector of the input interface unit adopts a long-short pin structure and has dual hot-swap protection functions in both software and hardware, enabling reliable hot-swap while powered on. The control unit can be software-defined to set protection thresholds and strategies, realizing inverse time-limit protection, fast short-circuit protection, and power switch control functions.

[0020] Third, the standard interface unit can meet the application requirements of spacecraft such as on-orbit service and maintenance, which require repairability, replacement, upgradeability, reconfigurability, expandability, and flexible load-bearing. Attached Figure Description

[0021] Figure 1 This is a block diagram of the standard interface unit of the distributed power system of the present invention;

[0022] Figure 2 This invention employs a distributed, reconfigurable spacecraft power system architecture with standard interface units.

[0023] Figure 3 This invention relates to a bidirectional solid-state switch module;

[0024] Figure 4 Flowchart of the timer interrupt routine for the control unit module;

[0025] Figure 5 Here is the PWM interrupt flowchart for the control unit module;

[0026] Figure 6 This is a schematic diagram of the standard interface unit structure;

[0027] Figure 7 This is a schematic diagram of the installation of the standard interface unit;

[0028] Figure 8 Diagram of long and short pin connectors for the input interface module;

[0029] Figure 9 Define the power terminal node for the input interface module;

[0030] Figure 10 Define the signal terminal nodes for the input interface module;

[0031] Figure 11 Define the contact points for the output interface module. Detailed Implementation

[0032] To make the objectives and advantages of this invention clearer, the invention will be specifically described below with reference to embodiments. It should be understood that the following text is merely used to describe one or more specific embodiments of the invention and does not strictly limit the scope of protection specifically claimed by the invention.

[0033] Example

[0034] 1. Overall Design Scheme

[0035] A standard interface unit for a distributed spacecraft power system, its schematic diagram is shown below. Figure 1 It mainly includes: an input interface module, a bidirectional solid-state switch module, a control unit module, an auxiliary power supply module, a CAN communication module, an isolation drive unit, a signal acquisition module, a current threshold protection module, a hot-swappable module, an indicator module, and an output interface module, among which:

[0036] Input interface module: responsible for connecting the standard interface unit to the DC bus and communication bus of the distributed system.

[0037] Bidirectional solid-state switch module: responsible for connecting or disconnecting the main power input and output interfaces.

[0038] Control Unit Module: The core component of the control circuit of the standard interface unit, responsible for data acquisition, digital-to-analog conversion, system fault diagnosis, solid-state switch control, communication with the host computer, and implementation of software protection.

[0039] Auxiliary power supply module: Converts the input voltage to a low voltage used by various modules in the system to power the entire system.

[0040] CAN communication module: Enables data and command communication between the standard interface unit and the host computer.

[0041] Isolation driver module: It adopts optocoupler isolation driver. The PWM wave control signal generated by the CPU drives the solid-state switch through the isolation driver module, which can ensure that the control circuit is isolated from the drive signal electrical components.

[0042] Signal acquisition module: includes main circuit input and output voltage, current and temperature acquisition circuits, and inputs the acquired signals to the CPU's digital-to-analog conversion interface for digital-to-analog conversion.

[0043] Current threshold protection module: Hardware implementation of current threshold protection, including blocking the power transistor drive optocoupler input and blocking the PWM output by the DSP on-chip comparator drive fault signal.

[0044] Hot-swap and indicator module: Enables hot-swapping and uses the connector's long and short pins to transmit information to the CPU regarding whether the connector is fully inserted, preventing system damage caused by starting the system with an incompletely inserted connector. Different colored LEDs indicate three connector states: connected, on / off, and fault protection.

[0045] Output interface module: responsible for connecting standard interface units to distributed power modules or loads.

[0046] Distributed reconfigurable spacecraft power system architecture composed of standard interface units, such as Figure 2 As shown. The standard interface unit structure is as follows. Figure 6 As shown. The standard interface unit is installed in the power controller of the distributed generation or energy storage unit. Specifically, the distributed power controller that installs the standard interface unit is as follows: Figure 7 As shown.

[0047] 2. Input Interface Module

[0048] The input interface module connector features a pin configuration with varying lengths, including positive power pins, negative power pins, a ground pin, CAN communication pins (CAN_H, CAN_L, CAN_GND, CAN_Shield), and SWAP hot-swappable pins. The ground pin is the longest, the positive power pin, negative power pin, and CAN communication pin are of medium length, and the SWAP hot-swappable pin is the shortest. The input interface module's pin configuration is as follows: Figure 8 As shown, the definitions of the power pin and the signal pin are as follows: Figure 9 and Figure 10 As shown.

[0049] The power positive pin connects the standard interface unit's power positive line to the bus's power positive line, the power negative pin connects the standard interface unit's power negative line to the bus's power negative line, the communication pin connects the standard interface unit to the communication bus, and the SWAP hot-swap pin detects the insertion / removal status. The ground pin is the longest and establishes the standard interface unit's ground potential first. The power and communication pins are in the middle; after a reliable ground connection, the power and communication connections are completed. Finally, the hot-swap pin is the shortest; when the hot-swap pin is connected, it connects to the ground wire, triggering the control circuit to send a start signal, activating the solid-state switch, and powering on the system.

[0050] 3. Bidirectional solid-state switch module

[0051] The bidirectional solid-state switch module consists of three MOSFETs. The main path consists of two anti-series MOSFETs, and the other MOSFET forms a freewheeling circuit when the switch is off, with the current flowing through its body diode.

[0052] Solid-state switches require bidirectional current flow, therefore two anti-series MOSFETs are used, driven and controlled by an optocoupler. In addition, a always-off MOSFET is needed to form a freewheeling circuit for the main circuit. The solid-state bidirectional switch circuit design is as follows: Figure 3 As shown.

[0053] When Q1 is on, current flows from the conductive channel of Q1 through the body diode of Q2 to PV2, achieving conduction from PV1 to PV2. When Q2 is on, current flows from the conductive channel of Q2 through the body diode of Q1 to PV1, achieving conduction from PV2 to PV1. Due to the unidirectional conductivity of the body diode, there is no reverse current flow, thus achieving the function of a bidirectional switch. In actual operation, the two MOSFETs will be in a fully on state for a long time. At the moment of switching on and off, the parasitic inductance on the line will generate a large voltage surge, which can break down the MOSFET if it is too large. Therefore, an RC (C1, R1) circuit is connected in parallel between the two MOSFETs to absorb the large voltage generated by the parasitic inductance, and at the same time, it can suppress the voltage spike during the reverse recovery process of the anti-parallel diode of the MOSFET. The function of Q3 is to use its body diode to provide a freewheeling circuit for the current generated by the inductive element when Q1 or Q2 is turned off. Capacitors C4 and C5 are the absorption capacitors of the bus. (If the MOSFET overheats significantly or its on-state voltage drop exceeds the required value during testing, the switch in each direction can be composed of two MOSFETs connected in parallel. This reduces internal resistance, on-state voltage drop, and temperature.)

[0054] 4. Control Unit Module

[0055] The control unit includes an I / O submodule, a PWM submodule, a comparator submodule, an ADC conversion submodule, and a CAN communication submodule. The software program for the standard interface unit runs within the control unit module and is mainly divided into three parts: the main program, the timer interrupt program, and the PWM interrupt program. The main program primarily implements power-on initialization and important data recovery functions; the timer interrupt program mainly implements time recording, telemetry acquisition, parameter uploading, bus communication, and health diagnostics functions; and the PWM interrupt program mainly implements inverse time limit protection, short-circuit protection, and power switch control functions.

[0056] Main program:

[0057] After power-on, the main program begins execution, first initializing the entire system and restoring important data, including current protection thresholds and I... 2 After checking the enable and power switch states, the main program will enter a loop, waiting for an interrupt.

[0058] Timer interrupt routine:

[0059] Timer interrupt routines such as Figure 4 As shown. Figure 4 The overall process of timer interrupt, Figure 5 The time recording module's process is as follows: The timer interrupt records time data every 2ms after power-on, with t0 for seconds, t1 for minutes, and t2 for hours. After recording the time, the next state is determined based on instructions from the host computer.

[0060] A. Standby: The host computer enters standby mode and does not perform any operation when no command is sent.

[0061] B. Self-test: Upon first power-on and entering an interrupt, the system will enter a self-test state to perform a health test, including data such as voltage, current, and temperature. If the input voltage is within the normal range, the current is 0, and the temperature is normal, the health check is complete, and the program continues. Otherwise, an error signal is sent to the host computer.

[0062] C. Roll call response: One bit in the host computer instruction represents the broadcast roll call data. The slave computer needs to reply with roll call response data to the host computer.

[0063] D. Switch control: One bit in the host computer instruction indicates that the host computer is sending a switch instruction data. The slave computer needs to control the corresponding switch (turn on or off) according to the instruction at the next PWM interrupt and send response data to the host computer.

[0064] E. Bus Command: One bit in the host computer command indicates that the host computer is sending bus command data. That is, the host computer will send the current protection threshold to the slave computer. After parsing the threshold, the slave computer will modify the threshold data in the protection program. Subsequently, the slave computer will send a bus command response sequence.

[0065] F. Polling Telemetry: One bit in the host computer command indicates that the host computer is sending a telemetry polling command, and the slave computer will send the required telemetry data information.

[0066] G. Time Correction: One bit in the host computer instruction indicates that the host computer is sending broadcast time data. The slave computer checks whether the recorded time data matches the time sent by the host computer. If they do not match, the host computer's time data is used as the standard for correction.

[0067] PWM interrupt routine:

[0068] The PWM interrupt operates at a frequency of 10kHz and is primarily responsible for power switch control and fault protection. The program flowchart is as follows: Figure 5 As shown.

[0069] First, the program will determine the current magnitude. If the current is greater than the short-circuit protection threshold, the power switch will be disconnected directly. If the current is less than the short-circuit protection threshold but greater than the I²t protection threshold, the inverse time current protection will be activated. The condition for one action is as follows.

[0070]

[0071] If the protection value reaches the threshold, the protection will activate with a delay of t = 0.0001M; otherwise, it will not activate and will wait for the next interruption to continue accumulating.

[0072] The PWM interrupt contains two states.

[0073] a. Standby: The state that does not require a power switch and does not perform any operation.

[0074] b. Control: Control the power switch according to the instructions from the host computer.

[0075] 5. Hot-swappable and indicator module

[0076] The system only starts when the connector is detected to be fully inserted. Hot-swapping protection includes both hardware and software solutions to prevent circuit damage in the event of a single protection failure, thereby increasing system reliability and security. The SWAP pin outputs a SWAP_IN signal via a transistor, which is sent to both the CPU and the driver circuit.

[0077] On the PIO port, the CPU does not start the system when it detects that the PIO port is low. When the connector is fully inserted, the SWAP ground is pulled low, the transistor is turned off, and the SWAP_IN is pulled up to a high level by the pull-up resistor. The CPU starts the system when it detects that the PIO port is high. This is a hot-swappable software protection scheme.

[0078] The SWAP_IN signal is also connected to the driver circuit. When the connector is not fully inserted, SWAP_IN is low, pulling the positive input port of the isolation driver optocoupler low. At this time, regardless of the PWM level, the isolation driver optocoupler will not conduct. When the connector is fully inserted, SWAP_IN becomes high, the diode is reverse-biased and cut off, and the positive input port of the isolation driver optocoupler is at the same level as the PWM wave output by the CPU. That is, the optocoupler conducts when the PWM is high and turns off when the PWM is low. This is the hot-swap hardware protection scheme.

[0079] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances. In the description of this specification, references to terms such as "an embodiment," "example," and "specific example" indicate that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples.

[0080] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described or explained in this invention are implemented according to conventional methods in the art unless otherwise specified or limited.

Claims

1. A standard interface unit for a distributed spacecraft power system, characterized in that, include: Input interface module: Used to connect the standard interface unit to the DC bus and communication bus of the distributed system; Bidirectional solid-state switch module: used to connect or disconnect the main power input and output interfaces; Control unit module: used for data acquisition, digital-to-analog conversion, system fault diagnosis, solid-state switch control, communication with the host computer, and implementation of software protection; Auxiliary power supply module: Used to convert the input voltage into a low voltage used by various modules in the system to power the entire system; CAN communication module: used to enable data and command communication between the standard interface unit and the host computer; Isolation driver module: adopts optocoupler isolation driver; Signal acquisition module: used to acquire signals input to the CPU's digital-to-analog converter interface for digital-to-analog conversion; Current threshold protection module: used to implement current threshold protection; Hot-swap and indicator module: On the one hand, it is used to realize hot-swap. It uses the long and short pins of the connector to transmit information to the processor whether the connector is fully inserted. When fully inserted, it controls the system to start; when not fully inserted, it does not start the system. On the other hand, different colored LEDs are used to indicate three states: connector connection, switch on / off, and fault protection. It also includes an output interface module and an input interface module. The output interface module is used to connect the standard interface unit to the distributed power module or the load. The connector of the input interface module adopts a long and short pin structure, including a power positive line pin, a power negative line pin, a ground pin, a CAN communication pin, and a SWAP hot-swappable pin. Among them, the grounding pin is longer than the power positive line pin, the power positive line pin, the power negative line pin and the CAN communication pin are of equal length, and the SWAP hot-swappable pin is shorter than the power positive line pin. The positive power line pin connects the positive power line of the standard interface unit to the positive power line of the DC bus; the negative power line pin connects the negative power line of the standard interface unit to the negative power line of the DC bus; the communication pin connects the standard interface unit to the communication bus; and the SWAP hot-swap pin detects the insertion / removal status. During the insertion process, the grounding pin is connected first to establish the potential of the standard interface unit structure; the power positive line pin, power negative line pin, and CAN communication pin are in the middle, and the connection is completed after reliable grounding, connecting the power and communication parts. The SWAP hot-swap pins are finally plugged in. Once the SWAP hot-swap pins are connected, the control circuit sends a start signal to turn on the solid-state switch and power on the system.

2. The standard interface unit for a distributed spacecraft power system according to claim 1, characterized in that: The bidirectional solid-state switch module consists of three MOSFETs. The main path consists of two anti-series MOSFETs, and the other MOSFET forms a freewheeling circuit when the switch is off, with the current flowing through its body diode.

3. The standard interface unit for a distributed spacecraft power system according to claim 1, characterized in that: The control unit module includes an IO submodule, a PWM submodule, a comparator submodule, an ADC conversion submodule, and a CAN communication submodule. The software program of the standard interface unit runs in the control unit module and is divided into three parts: the main program, the timer interrupt program, and the PWM interrupt program.

4. A standard interface unit for a distributed spacecraft power system according to claim 3, characterized in that: The main program begins execution after power-on, initializing the entire system and restoring important data, including current protection thresholds, etc. After checking the enable and power switch states, the main program will enter a loop, waiting for an interrupt.

5. A standard interface unit for a distributed spacecraft power system according to claim 3, characterized in that: The timer interrupt routine records time data every 2ms after power-on. For seconds, For the purpose of dividing, The time is recorded in hours. After the time is recorded, the host computer determines the next state, including the following states: A. Standby: The host computer enters standby mode without sending any instructions and does not perform any operations; B. Self-test: Upon first power-on and entering an interrupt, the system will enter a self-test state to perform a health test, including voltage, current, and temperature. If the input voltage is within the normal range, the current is 0, and the temperature is normal, the health diagnosis is complete and the program continues; otherwise, an error signal is sent to the host computer. C. Roll call response: One bit in the host computer command represents broadcast roll call data, and the slave computer needs to reply with roll call response data to the host computer. D. Switch control: One bit in the host computer instruction indicates that the host computer is sending a switch instruction data. The slave computer controls the corresponding switch according to the instruction at the next PWM interrupt and sends response data to the host computer. E. Bus command: One bit in the host computer command indicates that the host computer is sending bus command data. That is, the host computer will send the current protection threshold to the slave computer. After the slave computer parses the threshold, it will modify the threshold data in the protection program. Then the slave computer will send the bus command response sequence. F. Polling Telemetry: One bit in the host computer command indicates that the host computer is sending a telemetry polling command, and the slave computer will send the required telemetry data information. G. Time Correction: One bit in the host computer instruction indicates that the host computer is sending broadcast time data. The slave computer checks whether the recorded time data matches the time sent by the host computer. If they do not match, the host computer's time data is used as the standard for correction.

6. A standard interface unit for a distributed spacecraft power system according to claim 3, characterized in that: The PWM interrupt routine includes two states: a. Standby: A state that does not require a power switch to enter and does not perform any operation; b. Control: Control the power switch according to the instructions from the host computer.

7. A standard interface unit for a distributed spacecraft power system according to claim 3, characterized in that: In the hot-swap and indication module, the system is only started when the connector is detected to be fully inserted. The hot-swap protection is divided into two schemes: hardware and software. The SWAP pin outputs a SWAP_IN signal through a transistor. The SWAP_IN signal is output to the CPU and also to the driver circuit. Hot-swap software protection scheme: The SWAP pin is designed to be short. When the standard interface is connected to the system, due to the short length of the SWAP pin, the SWAP pin is floating, the transistor is turned on, and SWAP_IN is pulled low. SWAP_IN is connected to a GPIO port of the processor. When the processor detects that this GPIO port is low, it will not start the system. When the connector is fully inserted, SWAP ground is pulled low, the transistor is turned off, and SWAP_IN is pulled up to a high level by the pull-up resistor. When the processor detects that this IO port is high, the system starts working. Hot-swap hardware protection scheme: The SWAP_IN signal is also connected to the driver circuit. When the connector is not fully inserted, SWAP_IN is low, which pulls the positive input port of the isolation driver optocoupler low. At this time, the isolation driver optocoupler will not conduct. When the connector is fully inserted, SWAP_IN becomes high, the diode is reverse-biased and cut off, and the positive input port of the isolation driver optocoupler is the same as the PWM wave level output by the processor. That is, the optocoupler is turned on when the PWM is high and turned off when the PWM is low.

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