Multi-bus spacecraft power system

Abstract

The utility model discloses a kind of multi-mother-wire spacecraft power supply systems, it includes: N parallel solar cell array module, N boost MPPT module, the output end of each solar cell array module is electrically connected with the input end of corresponding boost MPPT module;N switch circuit, the input end of each switch circuit is electrically connected with the output end of corresponding boost MPPT module;First busbar, second busbar and third busbar;Boost MPPT module is equipped with mode control end, the mode control end is electrically connected with the mode selection end of corresponding switch circuit, make the on path of switch circuit change with MPPT module output voltage threshold value and switch over.The utility model has the advantages such as strong compatibility, high energy utilization, flexible and simple architecture, high energy conversion efficiency, intelligent deployment ability and strong anti-failure ability.

Description

Technical Field

[0001] This utility model relates to the field of spacecraft power systems, and in particular to a multi-bus spacecraft power system based on MPPT (maximum power point tracking) technology. Background Technology

[0002] The power system is a critical subsystem of a spacecraft. Most spacecraft power systems use a system solution consisting of solar arrays, battery packs, and power controllers. It mainly realizes functions such as energy collection, storage, management, conversion, and distribution, providing a stable and reliable energy supply that meets the voltage and power requirements of all other subsystems on the spacecraft.

[0003] There are two types of power systems in existing spacecraft: S3R (Switched Shunt Regulator) single-battery multi-bus power systems and S3R dual-battery multi-bus power systems. Figure 1 The diagram shows the structure of the S3R single-battery multi-bus power system. This system uses multiple parallel 42V solar cell arrays and an S3R shunt regulator to supply power to the primary bus. The 42V primary bus is then stepped down and converted to 28V and 16V secondary buses. Figure 2 This is a structural diagram of the S3R dual-battery multi-bus power system. The system design includes two primary buses: a 42V primary bus and a 28V primary bus. The corresponding solar cell arrays and S3R shunt regulators are divided into two groups: m 42V solar cell arrays and S3R shunt regulators are connected in parallel to power the 42V primary bus, and n 28V solar cell arrays and S3R shunt regulators are connected in parallel to power the 28V primary bus. The 16V bus is designed as a secondary bus, obtained by voltage transformation using an isolated DC-DC converter.

[0004] In practical use, the existing spacecraft power systems, including the S3R multi-bus power system and the S3R dual-battery multi-bus power system, have the following drawbacks: 1. Low energy efficiency: Different types of bus voltages require multiple voltage conversion stages, resulting in significant energy loss. For example, in the S3R single-battery multi-bus power supply system, the 42V primary bus needs to be stepped down to 28V and 16V secondary buses, and this multi-stage conversion reduces energy efficiency. 2. Low energy utilization of solar cell array: S3R technology cannot make the solar cell array work at the maximum power point, resulting in the solar cell array not being able to output maximum power and low energy utilization. 3. High system complexity: In the S3R dual-battery multi-bus power system, two different specifications of batteries and solar arrays are required, increasing system complexity and cost. The bus power grid connection circuit is complex, and energy transmission between buses requires voltage transformation, further increasing energy loss. 4. Poor scalability and compatibility: Existing power systems are difficult to adapt to various specifications of solar cell arrays and battery packs, which is not conducive to mass production and cost reduction.

[0005] To address this, an invention patent with publication number CN110148995A discloses a reconfigurable power system architecture for spacecraft, including a solar cell array, a battery bank, a source bus, a functional switch module, a DC / DC converter module, and a load bus. The solar cell array and battery bank, acting as the source, are connected to a segmented source bus via the functional switch module. The source bus is connected to the load bus via the DC / DC converter module, enabling energy conversion. The DC / DC converter has the capability to be reconfigured into an MPPT module, a battery charging module, a battery discharging module, and other functional modules. Through the functional switch module and reconfiguration algorithm, various operating modes of the power system are switched, overcoming the shortcomings of traditional spacecraft power systems, such as fixed modules, unchangeable functions, and large system size. This achieves upgrades in power system output capacity, energy expansion, fault reconfiguration, and modular design.

[0006] Another invention patent, CN11379163A, discloses a high-power spacecraft power system based on maximum power point tracking (MPPT) technology for solar arrays. This power system achieves integrated MPPT and SR (shunt regulation) control, real-time maximum power point tracking of the solar array output, autonomous charging management of the lithium-ion battery pack, reliable and safe establishment of the primary bus, and autonomous fault isolation. The system comprises multiple MPPT power regulation modules, a lithium-ion battery pack, one or more SR power regulation modules, and one or more solar arrays. This power system features high solar array utilization, autonomous charging management of the lithium-ion battery pack, easy system power expansion, high bus quality, flexible power supply, and high reliability, making it particularly suitable for deep space exploration applications with large environmental temperature variations and high system specific energy requirements.

[0007] While the aforementioned prior art mentions the application of MPPT power regulation modules, it primarily focuses on the design and optimization of single load buses and battery packs (e.g., CN110148995A and CN11379163A). However, in large spacecraft or complex space missions, multiple load buses often exist, each with different requirements for voltage, current, and power parameters. For instance, the characteristics of load buses vary significantly across different functional modules within a spacecraft, such as communication systems, attitude control systems, and scientific instruments. A power system architecture with a single load bus is insufficient to meet the differentiated power supply needs of multiple load buses, potentially leading to some loads not receiving adequate power and impacting the overall functionality of the spacecraft. Furthermore, in actual space missions, multiple battery packs are sometimes required to improve system reliability, increase energy reserves, or meet the specific needs of different loads. For example, in long-duration missions, multiple battery packs may need to work collaboratively to ensure that the spacecraft has sufficient energy to maintain critical systems even when solar arrays are not functioning properly (e.g., when entering Earth's shadow). However, existing technologies lack effective solutions for the coordinated management of multiple battery packs, balanced charging and discharging, and fault isolation. Imbalances in charge and charging / discharging conflicts may occur between multiple battery packs, affecting the performance and reliability of the entire power system and potentially causing malfunctions that could lead to mission failure. Furthermore, to address the limitations of traditional SR (series shunt regulation) control methods used in spacecraft power systems, which cannot achieve reasonable design under large variations in temperature and light intensity and thus fail to meet the needs of deep space missions, existing systems primarily consist of MPPT (Multi-Level Photovoltaic Power Supply), SR circuits, and batteries. While MPPT improves the utilization rate of the solar array, these existing solutions lack the capability to supply power to multiple buses and battery packs, and therefore cannot achieve energy allocation.

[0008] In summary, existing spacecraft power system architectures have achieved significant results in applications involving single load buses and battery packs, but they still have certain limitations when facing complex application scenarios such as multiple buses and multiple battery packs. Utility Model Content

[0009] A brief overview of embodiments of the present invention is provided below to provide a basic understanding of certain aspects of the invention. It should be understood that this overview is not an exhaustive summary of the invention. It is not intended to identify key or essential parts of the invention, nor is it intended to limit the scope of the invention. Its purpose is merely to present certain concepts in a simplified form as a prelude to the more detailed description that follows.

[0010] To address the shortcomings of existing technologies, this application provides a multi-bus spacecraft power system that employs MPPT technology. This system can be applied to multi-bus, multi-load, and multi-mission scenarios, and offers advantages such as higher energy utilization, multi-load power supply capability, high-efficiency energy collection, conversion, and storage, high power density, high cost-effectiveness, and ease of mass production.

[0011] Specifically, this utility model provides a multi-bus spacecraft power system, which includes: N parallel solar cell array modules, 2≤N≤8; N buck-boost MPPT modules, with the output terminal of each solar cell array module electrically connected to the input terminal of the corresponding buck-boost MPPT module via a copper busbar hard wire; N switching circuits, each switching circuit having an input terminal, a first output terminal, a second output terminal, a third output terminal, and a mode selection terminal, wherein the input terminal is electrically connected to the output terminal of the corresponding buck-boost MPPT module; The first busbar, the second busbar, and the third busbar are used to provide different voltage values ​​(e.g., 28V, 42V, and 12V). Wherein, the first output terminal is electrically connected to the first bus, the second output terminal is electrically connected to the second bus, and the third output terminal is electrically connected to the third bus; The step-up / step-down MPPT module is provided with a mode control terminal, which is electrically connected to the mode selection terminal of the corresponding switching circuit, so that the conduction path of the switching circuit switches as the output voltage threshold of the MPPT module changes. The first filter capacitor, the second filter capacitor, and the third filter capacitor are connected in parallel between the first busbar, the second busbar, and the third busbar and the spacecraft structural ground, respectively. The three battery packs are electrically connected to the first bus, the second bus, and the third bus via normally open contacts of magnetic latching relays, respectively. The load equipment is powered by the first bus, the second bus and the third bus respectively.

[0012] Furthermore, the first bus outputs 42V, the second bus outputs 28V, and the third bus outputs 16V.

[0013] Furthermore, the three battery packs are configured with the same voltage or different voltages. As a feasible solution, the three battery packs are a 42V battery pack, a 28V battery pack, and a 16V battery pack. The 42V battery pack is connected in parallel to the first bus, the 28V battery pack is connected in parallel to the second bus, and the 16V battery pack is connected in parallel to the third bus. Each battery pack is electrically connected to its corresponding bus via a grid-connected controller, which is a magnetic latching relay or a back-to-back MOSFET array, to achieve on / off switching. The load devices (42V devices, 28V devices, and 16V devices) are respectively plugged into the first, second, and third bus via connectors, forming pluggable load interfaces.

[0014] Furthermore, the first busbar, the second busbar, and the third busbar are all primary busbars.

[0015] Furthermore, the switching circuit is implemented using a magnetic latching relay or a back-to-back MOSFET array.

[0016] This utility model includes multiple parallel solar cell array modules, multiple switching circuits, multiple buck-boost MPPT modules, multiple buses, multiple filter capacitors, multiple battery banks, and multiple load devices. Each solar cell array module is connected to a corresponding switching circuit via a buck-boost MPPT module. Each switching circuit has three outputs, each connected to a different bus. The filter capacitors, battery banks, and load devices are each connected to a different bus. The buck-boost MPPT modules and switching circuits work together to switch the power system's operating mode. This solution provides a multi-bus spacecraft power system. Each solar cell array is connected to a corresponding primary bus via an MPPT controller, enabling maximum power point tracking (MPPT) of the solar cell array and improving energy utilization. The MPPT controller adjusts the output voltage of the solar cell array to the voltage level required by the primary bus, reducing voltage conversion steps and improving energy utilization. The more efficient switching circuits enable intelligent energy allocation between different buses. Based on the mission requirements of the spacecraft and changes in the space environment, the energy distribution of each bus is dynamically adjusted, providing flexible energy management for the operation of multi-payload spacecraft and on-orbit mission planning; thus solving the problems of low energy utilization, high system complexity and poor compatibility in existing technologies.

[0017] Compared with the prior art, the present invention has the following technical advantages: 1. Strong compatibility: Adopting a modular design, the solar cell array module, buck-boost MPPT module and switching circuit can use the same specifications of products, realizing product modularization and easy mass production manufacturing.

[0018] 2. High energy efficiency: The buck-boost MPPT module can achieve maximum power point tracking of the solar cell array, improving energy efficiency.

[0019] 3. Flexible and simple architecture: The power system and busbars are easily expandable and can be flexibly adjusted according to task requirements.

[0020] 4. High energy conversion efficiency: Multiple busbars are designed as primary busbars, reducing multi-stage voltage conversion links and improving energy conversion efficiency.

[0021] 5. Intelligent allocation capability: Energy from multiple busbars can be intelligently allocated, enhancing the power supply capacity of the busbars.

[0022] 6. Strong fault resistance: The solar cell array, buck-boost MPPT module and bus can be switched and connected through a switching circuit to achieve redundant design and fault isolation, resulting in high system reliability. Attached Figure Description

[0023] This invention can be better understood by referring to the following description taken in conjunction with the accompanying drawings, in which the same or similar reference numerals are used throughout the drawings to denote the same or similar parts. These drawings, together with the following detailed description, are incorporated in and form part of this specification, and are used to further illustrate preferred embodiments of the invention and explain the principles and advantages of the invention. In the drawings: Figure 1 This is a schematic diagram of the existing S3R multi-bus power supply system scheme; Figure 2 This is a schematic diagram of the existing S3R dual-battery multi-bus power system scheme. Figure 3 This is a schematic diagram of the structure of the multi-bus spacecraft power system of this utility model. Detailed Implementation

[0024] Embodiments of the present invention will now be described with reference to the accompanying drawings. Elements and features described in one drawing or embodiment of the present invention may be combined with elements and features shown in one or more other drawings or embodiments. It should be noted that, for clarity, representations and descriptions of components and processes unrelated to the present invention and known to those skilled in the art have been omitted from the drawings and description.

[0025] In the description of this utility model, it should be understood that the terms "installation," "connection," and "linking" 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 or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0026] This utility model provides a multi-bus spacecraft power system, which aims to solve the problems of low energy utilization, high system complexity, and poor compatibility in the prior art.

[0027] The power system of this invention adopts a modular design, including multiple parallel solar cell arrays and buck-boost MPPT modules (MPPT controllers), as well as multiple primary buses. Each solar cell array is connected to its corresponding primary bus through a buck-boost MPPT module, enabling maximum power point tracking of the solar cell array and improving energy utilization.

[0028] The system is designed with multiple primary buses, each corresponding to a solar cell array and a buck-boost MPPT module. The MPPT module adjusts the output voltage of the solar cell array to the voltage level required by the primary bus, reducing voltage conversion steps and improving energy efficiency.

[0029] Intelligent energy allocation: Utilizing more efficient switching circuits, intelligent energy allocation between different buses is achieved. Based on the spacecraft's mission requirements and changes in the space environment, the energy distribution of each bus is dynamically adjusted, providing flexible energy management for multi-payload spacecraft operations and on-orbit mission planning.

[0030] For details, see Figure 3 The multi-bus spacecraft power system in this embodiment includes: N parallel solar cell array modules, 2≤N≤8; N buck-boost MPPT modules; First busbar VBUS1, second busbar VBUS2, third busbar VBUS3; There are N switching circuits, each of which (a three-to-one switching circuit) has an input terminal, a first output terminal, a second output terminal, a third output terminal, and a mode selection terminal. The input terminal is electrically connected to the output terminal of the corresponding buck-boost MPPT module. The first output terminal is electrically connected to the first bus VBUS1, the second output terminal is electrically connected to the second bus VBUS2, and the third output terminal is electrically connected to the third bus VBUS3. The buck-boost MPPT module is equipped with a mode control terminal; the input terminal of each buck-boost MPPT module is hardwired to the solar cell array module, and the mode control terminal is hardwired to VBUS1, VBUS2, and VBUS3 respectively via a three-to-one switch circuit, so that the conduction path of the switch circuit switches according to the change of the MPPT module output voltage threshold. The first filter capacitor, the second filter capacitor, and the third filter capacitor are connected in parallel between the first busbar, the second busbar, and the third busbar and the spacecraft structural ground, respectively. The three battery packs are electrically connected to the first busbar VBUS1, the second busbar VBUS2 and the third busbar VBUS3 respectively via the normally open contacts of the magnetic latching relays. The load device is connected to the VBUS1, VBUS2 or VBUS3 copper busbar via a connector.

[0031] This utility model's embodiment of a multi-bus spacecraft power system includes N parallel-connected solar cell array modules, a step-up / step-down MPPT module, a switching circuit, a bus, filter capacitors, and a battery pack. Each solar cell array module is connected to its corresponding switching circuit via a step-up / step-down MPPT module, and then connected to the bus. In actual implementation, the aforementioned step-up / step-down MPPT module and the three-stage bus copper bus are mounted on the same side of a heat-dissipating aluminum plate, forming a solar cell array-MPPT-cascaded bus structure.

[0032] In this embodiment, the first bus, second bus, and third bus are all primary buses. The first bus outputs 42V, the second bus outputs 28V, and the third bus outputs 16V. Three battery banks are connected: a 42V battery bank, a 28V battery bank, and a 16V battery bank. The 42V battery bank is connected in parallel to the first bus, the 28V battery bank is connected in parallel to the second bus, and the 16V battery bank is connected in parallel to the third bus. Each battery bank is electrically connected to its corresponding bus via a grid-connected controller. Load devices (42V devices, 28V devices, and 16V devices) are connected to the first, second, and third bus via connectors, forming pluggable load interfaces.

[0033] Switching circuits: Relay circuits (such as magnetic latching relays) or electronic switching circuits (such as MOSFET arrays) can be used. Multiple switching channels can be designed to correspond to different buses, depending on system requirements and the number of buses. The switching circuits have functions such as protection against reverse current and fault isolation.

[0034] Busbar design: The number of busbars is flexibly designed according to the needs of the system's electrical equipment. Each busbar connects multiple solar cell array modules, buck-boost MPPT modules, and switching circuits.

[0035] Filter capacitors and battery packs: Filter capacitors are used for filtering, and battery packs are used for storing energy and providing energy output to the system when the power supply from the solar array is insufficient.

[0036] Load equipment: The bus provides power to the load equipment to meet the different mission requirements of the spacecraft.

[0037] The power supply system of this invention can switch between different power supply system operating modes based on the buck-boost MPPT module and the switching circuit. The power supply system operating modes include: Normal operating mode: Each solar cell module is connected to the bus via a corresponding buck-boost MPPT module and switching circuit to supply power to the load equipment. The buck-boost MPPT module operates in either maximum power point tracking mode or constant voltage charging mode, depending on the battery pack's charge level.

[0038] Intelligent power allocation mode 1 for bus: When the power of the load equipment on a certain bus increases or the power generation of the solar cell array is insufficient, the energy of other buses can be allocated through the switching circuit to jointly power the load equipment on that bus.

[0039] Bus power intelligent allocation mode 2: In more complex situations, the energy of multiple solar cell array modules can be simultaneously allocated to a single bus to meet high power requirements.

[0040] Bus power failure mode: If a bus fails, the switching circuit can switch to other channels to isolate the fault and ensure the continuous operation of other buses.

[0041] Failure mode of solar cell array or buck-boost MPPT module: If the solar cell array or buck-boost MPPT module fails, the switching circuit can be switched to neutral to disconnect the connection, isolate the fault, and provide power from other channels.

[0042] This utility model's system adopts a modular design. In this embodiment, it includes three parallel branches. Each branch includes a solar cell array module (1-1, 1-2, 1-3), a step-up / step-down MPPT module (2-1, 2-2, 2-3), a switching circuit (3-1, 3-2, 3-3), a bus (4-1, 4-2, 4-3), filter capacitors (5-1, 5-2, 5-3), a battery pack (6-1, 6-2, 6-3), and load equipment (7-1, 7-2, 7-3). The solar cell array module is used to collect solar energy and convert it into electrical energy. The step-up / step-down MPPT module realizes the maximum power point tracking and power conversion of the solar cell array. The switching circuit has three outputs, which are connected to the bus (4-1, 4-2, 4-3) respectively, for realizing intelligent energy allocation between different buses. In this system, multiple power supply buses are designed as primary buses, and each primary bus corresponds to a set of solar cell arrays and MPPT controllers, effectively improving energy utilization. The filter capacitors can be implemented using multiple filter capacitors connected in series and parallel. The battery packs are configured with different voltages (42V, 28V, and 16V). The load devices are different devices connected to the bus.

[0043] Currently, the application of MPPT power regulation modules in existing technologies is mainly aimed at single load buses and battery packs. In order to solve the defects of traditional spacecraft power system modules being fixed, having unchangeable functions, and being large in size, this application achieves fault isolation between solar cell arrays and DC-DC converter modules by switching the path through a switching module, or the battery pack is connected to the source bus through a relay in the functional switching module, so as to provide energy output and energy storage for the system under different needs.

[0044] In normal operating mode, DC / DC converters 6-1 and 6-2 are connected to the solar array and the load bus, operating in MPPT mode. DC / DC converter 6-3 is connected to the battery bank and the load bus, operating in charging or discharging mode. The DC / DC converters do not need to adapt to various solar array and battery bank voltages. In power output upgrade mode, DC / DC converters 6-1, 6-2, and 6-3 are connected to the battery bank and the load bus. The battery bank discharges through the DC / DC converters. DC / DC converters 6-1 and 6-2 are not connected to the solar array and cannot utilize the solar array's energy. In fault mode, fault isolation between the solar array and the DC / DC converters is achieved.

[0045] Furthermore, this application adopts the above-mentioned solution, which addresses the problems of low energy distribution efficiency among multiple buses, system complexity, the need for fixed adaptation design of solar cell arrays for different voltage buses, complex power distribution for multiple loads, difficulty in mass production, and difficulty in functional expansion in traditional spacecraft power systems, specifically for power systems with multiple load buses and multiple battery packs. A typical application of this utility model system consists of multiple buses with different voltages, multiple battery packs, buck-boost MPPT modules, and solar cell arrays. By adding a switching circuit between the buck-boost MPPT modules and the buses, the switching circuit switches the path, connecting different buck-boost MPPT modules to different buses, thus achieving energy distribution among different buses and also enabling fault isolation of the solar cell array, buck-boost MPPT modules, and buses in the power system. This utility model requires a solar cell array to manage the charging of battery packs with different voltages. The system switching circuit needs to effectively isolate the bus series current and have multi-channel switching capability. The buck-boost MPPT module used in the system needs to be suitable for applications where the input voltage is greater than the output voltage, the input voltage is less than the output voltage, and the input voltage is equal to the output voltage. Based on MPPT technology, the energy utilization rate of the solar cell array can be effectively improved, and the system has wide adaptive capability of input and output voltage. It is easy to adapt the solar cell array to various different voltage buses, and it is easy to design the modular design of the solar cell array and mass production.

[0046] In normal operation mode, the buck-boost MPPT module connects to different solar cell arrays and different buses, and operates in MPPT mode or constant voltage charging mode. The buck-boost MPPT module intelligently adapts to the connection voltage of the solar cell array and the bus.

[0047] This utility model features intelligent bus power allocation modes 1 and 2, allowing multiple solar cell arrays and multiple buck-boost MPPT modules to simultaneously power the same bus. The buck-boost MPPT modules operate in MPPT mode or constant voltage charging mode, fully utilizing the energy from the solar cell arrays. Meanwhile, other buses can be powered by battery banks, maintaining operational continuity. A fault mode enables isolation between the solar cell arrays, buck-boost MPPT modules, and different buses in case of faults.

[0048] This invention adopts the above-mentioned solution, possessing the advantages of strong compatibility. It can utilize the same solar cell array, MPPT module, and channel switching circuit, facilitating mass production. This invention is easily expandable in power, enabling high-power power systems. This invention effectively improves the energy utilization rate of spacecraft power systems. This invention utilizes a more efficient switching circuit to achieve intelligent energy allocation between different buses, providing flexible energy management for multi-payload spacecraft operation, on-orbit mission planning, and responses to changes in the space environment. Compatibility and scalability: The system is compatible with various specifications of solar cell arrays and battery packs, and can be widely applied to different types of spacecraft power systems. Through modular design, it is easy to expand and upgrade, meeting the energy needs of different spacecraft.

[0049] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, element, step, or component, but does not exclude the presence or addition of one or more other features, elements, steps, or components.

[0050] Although the present invention has been disclosed above through the description of specific embodiments, it should be understood that all the embodiments and examples described above are exemplary and not restrictive. Those skilled in the art can design various modifications, improvements, or equivalents to the present invention within the spirit and scope of the appended claims. These modifications, improvements, or equivalents should also be considered to be included within the protection scope of the present invention.

Claims

1. A multi-bus spacecraft power system, characterized in that: include: N parallel solar cell array modules, 2≤N≤8; There are N buck-boost MPPT modules, and the output terminal of each solar cell array module is electrically connected to the input terminal of the corresponding buck-boost MPPT module. N switching circuits, each switching circuit having an input terminal, a first output terminal, a second output terminal, a third output terminal, and a mode selection terminal, wherein the input terminal is electrically connected to the output terminal of the corresponding buck-boost MPPT module; The first busbar, the second busbar, and the third busbar are used to provide different voltages; Wherein, the first output terminal is electrically connected to the first bus, the second output terminal is electrically connected to the second bus, and the third output terminal is electrically connected to the third bus; The buck-boost MPPT module is provided with a mode control terminal, which is electrically connected to the mode selection terminal of the corresponding switching circuit. Three battery packs are connected to the first bus, the second bus, and the third bus, respectively; The load equipment is powered by the first bus, the second bus and the third bus respectively.

2. The multi-bus spacecraft power system according to claim 1, characterized in that: It also includes a first filter capacitor, a second filter capacitor, and a third filter capacitor, which are connected in parallel between the first busbar, the second busbar, and the third busbar and the spacecraft structural ground, respectively.

3. The multi-bus spacecraft power system according to claim 1, characterized in that: The first bus outputs 42V, the second bus outputs 28V, and the third bus outputs 16V.

4. The multi-bus spacecraft power system according to claim 1, characterized in that: The three battery packs are electrically connected to their respective busbars via a grid-connected controller.

5. The multi-bus spacecraft power system according to claim 1, characterized in that: The switching circuit is implemented using a magnetic latching relay or a MOSFET array.

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