Satellite power switching circuit and method of operation thereof

Abstract

The application provides a satellite power switching circuit and a running method thereof, which comprises a magnetic latching relay controller configured to provide a magnetic latching relay on-off signal; a magnetic latching relay contact configured to generate a control signal of a MOS power switch module according to the magnetic latching relay on-off signal, and provide the control signal of the MOS power switch module to the MOS power switch module; and the MOS power switch module configured to turn on or turn off a current path between a satellite power bus and a load power supply module according to the control signal of the MOS power switch module.

Description

Technical Field

[0001] This invention relates to the field of aerospace technology, and in particular to a satellite power switching circuit and its operation method. Background Technology

[0002] With the development of aerospace technology, satellite systems are increasingly demanding higher requirements for the reliability, lifespan, and power consumption of onboard power management units. During satellite operation, power switching circuits are needed to control the power supply to onboard computers, communication payloads, attitude control equipment, and other payloads to meet the needs of equipment power-on / off management, fault isolation, and power consumption scheduling.

[0003] Currently, magnetic latching relays are commonly used in satellite power systems as load power on / off control devices. Magnetic latching relays have advantages such as power-off retention, low static power consumption, strong electrical isolation capability, and strong resistance to the space environment, and are therefore widely used in satellite power distribution units and onboard equipment power supply control systems.

[0004] In the prior art, magnetic latching relays are usually connected in series between the satellite power bus and the load, and the relay contacts directly bear the load operating current. The typical structure is as follows: satellite power bus -- magnetic latching relay contacts -- load. That is, the magnetic latching relay simultaneously undertakes the control function and the power switching function.

[0005] However, in real-world satellite applications, loads typically have large starting and operating currents, especially during load power-on, motor startup, and capacitive load connection. Relay contacts need to withstand transient currents in the ampere range or even higher. Because relay contacts are mechanical contact structures, they are prone to arcing, contact erosion, and material migration during high-current switching. Summary of the Invention

[0006] The purpose of this invention is to provide a satellite power switching circuit and its operation method to solve the problem of low reliability caused by existing magnetic latching relays simultaneously undertaking control functions and power switching.

[0007] To solve the above-mentioned technical problems, the present invention provides a satellite power switching circuit, comprising: The magnetic latching relay controller is configured to provide on / off signals for the magnetic latching relay; The magnetic latching relay contacts are configured to generate a control signal for the MOS power switch module based on the on / off signal of the magnetic latching relay, and to provide the control signal of the MOS power switch module to the MOS power switch module; and The MOS power switch module is configured to turn on or off the current path between the satellite power bus and the load power supply module according to the control signal of the MOS power switch module.

[0008] Optionally, the satellite power switching circuit further includes: The gate drive and protection module is configured to connect between the output terminal of the magnetic latching relay contact and the control terminal of the MOS power switch module; and The load power supply module is configured to provide operating current to the satellite load.

[0009] Optionally, in the satellite power switching circuit, the gate drive and protection module includes: The gate current-limiting resistor is configured to provide a resistor that limits the gate current of the MOS power switch module; The gate pull-down resistor is configured to provide a resistor that limits the gate voltage of the MOS power switch module; The voltage regulator protection device is configured to provide a first protection shutdown signal for gate overvoltage faults in the MOS power switching module; and The transient suppression protection device is configured to provide a second protection shutdown signal for gate transient overcurrent faults of the MOS power switch module.

[0010] Optionally, in the satellite power switching circuit, the MOS power switching module forms a power on / off path through a combination of multiple metal-oxide-semiconductor field-effect transistors, which includes multiple parallel conducting branches, wherein each parallel conducting branch includes multiple series-connected shut-off branches.

[0011] Optionally, in the satellite power switching circuit, the MOS power switch module includes a first parallel conduction branch and a second parallel conduction branch; The first parallel conducting branch and the second parallel conducting branch are connected in parallel between the satellite power bus and the load power supply module to divert the current path between the satellite power bus and the load power supply module. The first parallel conducting branch includes a first series shut-off branch and a second series shut-off branch connected in series, and the second parallel conducting branch includes a third series shut-off branch and a fourth series shut-off branch connected in series. Both the first and second parallel conducting branches are connected in series through two MOS transistors to form a double disconnect path. When a power-off operation is performed, the two MOS transistors are redundantly turned off to form redundant isolation.

[0012] Optionally, in the satellite power switching circuit, the magnetic latching relay controller includes a first main unit control branch and a second standby unit control branch; The first host control branch provides the magnetic latching relay on / off signal to the first group of magnetic latching relay contacts; The second standby control branch provides the magnetic latching relay on / off signal to the second set of magnetic latching relay contacts; The first set of magnetic latching relay contacts provides the control signal for the first MOS power switch module; The second set of magnetic latching relay contacts provides control signals for the second MOS power switch module.

[0013] Optionally, in the satellite power switching circuit, the first host control branch includes a first parallel control branch and a second parallel control branch; and the second standby control branch includes a third parallel control branch and a fourth parallel control branch. The first parallel control branch controls the first magnetic latching relay contact to be normally closed and the second magnetic latching relay contact to be normally open. The second parallel control branch controls the normally open contacts of the first magnetic latching relay and the normally closed contacts of the second magnetic latching relay; The third parallel control branch controls the normally open contacts of the third magnetic latching relay and the normally closed contacts of the fourth magnetic latching relay; The fourth parallel control branch controls the normally closed contacts of the fourth magnetic latching relay and the normally open contacts of the third magnetic latching relay.

[0014] The present invention also provides a method for operating the satellite power switching circuit as described above, comprising: During the power-on process, the magnetic latching relay controller sends a load power-on command, and the magnetic latching relay contacts actuate. The magnetic latching relay contacts output a high-level control signal; The gates of two series-parallel MOS transistors obtain the turn-on voltage; Multiple MOSFETs are turned on simultaneously; the satellite power bus supplies power to the load power supply module through the MOSFET power switch module; During a power outage, the magnetic latching relay controller sends a power outage command, causing the magnetic latching relay contacts to reverse their action. The gate drive and protection module releases the MOS gate drive voltage; all MOS power switch modules are turned off; the output of the satellite power bus is isolated from the load power supply module.

[0015] Optionally, the operation method of the satellite power switching circuit further includes: When the satellite controller issues a load power-on command, the relay drive circuit receives the power-on control signal and outputs a positive pulse, causing the magnetic latching relay contacts to actuate. The magnetic latching relay contacts change from an open state to a closed state; The magnetic latching relay contacts output a control voltage, which is applied to the gate of the MOS power transistor via the gate drive resistor. The gate of the MOS power switch receives the turn-on voltage; During load power supply, the two parallel MOSFETs share the load current. When one of the MOS transistors experiences a fault such as increased on-resistance, performance degradation, or decreased current capability, the other parallel MOS transistor maintains the power supply path. When the satellite controller issues a load power-off command, the relay drive circuit outputs a reverse drive pulse, causing the magnetic latching relay contacts to reverse their action, the magnetic latching relay contacts to return to the open state, and the MOS gate drive voltage to be cut off. Release the MOS gate charge through the gate pull-down resistor; The gate-source voltage of the MOS power transistor decreases; All MOS devices are turned off, and the series MOS group is simultaneously cut off, achieving electrical isolation between the load and the satellite bus power supply. If a single MOS experiences a drain-source breakdown fault, a turn-off failure fault, or an abnormal increase in leakage current, another MOS provides isolation capability. Calculate the thermal shock power consumption of the magnetic latching relay contacts: ; When calculating the connection between the magnetic latching relay contacts and the main power circuit of the load, the operating current is 5A, and the relay on-resistance RCONTACT = 50mΩ. The calculated heat dissipation of the magnetic latching relay is 52 * 0.05 = 1.25W. Given that the relay's on-resistance RCONTACT = 50mΩ, RDS(ON) = 5 mΩ, and its operating current is 5A, then... Vdrop = I × Rc = 0.025V; The on-current of a single MOS is: ; The on-state current of the dual MOS transistors in parallel is: .

[0016] Optionally, the operation method of the satellite power switching circuit further includes: When the satellite controller issues a load power-on command or a load power-off command, if the first host control branch, the first set of magnetic latching relay contacts, or the first MOS power switch module malfunctions, the second standby control branch receives the power-on control signal or outputs a reverse drive pulse; the second set of magnetic latching relay contacts changes from the open state to the closed state. When the satellite controller issues a load power-on command, the first parallel control branch controls the second magnetic latching relay contact to be normally open, and the second parallel control branch controls the first magnetic latching relay contact to be normally open. When the satellite controller issues a load power-off command, the first parallel control branch controls the first magnetic latching relay contact to remain closed, and the second parallel control branch controls the second magnetic latching relay contact to remain closed.

[0017] In the satellite power switching circuit and its operation method provided by this invention, a magnetic latching relay controller provides a magnetic latching relay on / off signal. The magnetic latching relay contacts generate a control signal for the MOS power switch module based on the magnetic latching relay on / off signal. The MOS power switch module opens or closes the current path between the satellite power bus and the load power supply module based on the control signal of the MOS power switch module. This realizes that the magnetic latching relay contacts no longer bear the task of large current switching on the load side, but are only used to output the control signal of the MOS power switch module. This avoids the problems of arc discharge, contact erosion and material migration that are easily generated during large current switching in the traditional technology where the magnetic latching relay is directly connected in series with the main power circuit, as well as the low reliability caused by the magnetic latching relay bearing both control function and power switching.

[0018] The inventors of this invention discovered through research that magnetic latching relays, which simultaneously perform control and power switching functions and operate for extended periods, are prone to the following problems: 1. Contact adhesion failure; When the relay contacts close or open under high current conditions, the instantaneous high heat generated at the contacts may cause the surface material to melt, resulting in the two contacts sticking together. When the control signal requires the relay to open, the contacts remain in a conductive state, preventing the load from being shut off and affecting satellite fault isolation and safety control. Second, median failure; Magnetic latching relays rely on electromagnetic force and permanent magnets to maintain the contact state. When the contacts are subjected to large current surges for a long time, it may cause contact erosion, mechanical fatigue, and deformation of the spring, making the relay unable to stably maintain a fully closed or fully open state, but instead remaining in an intermediate position, resulting in unreliable contact or uncertain state. Third, the system voltage drop and power consumption increase; Because relay contacts have a certain contact resistance, when a large current passes through the relay contacts, a significant conduction voltage drop will be generated, resulting in power loss, reduced power supply link efficiency, and increased device temperature rise, which is not conducive to the long-term reliable operation of the satellite. Fourth, the selection of relays is limited; To meet the demands of high-current applications, larger magnetic latching relays are required. However, larger relays typically have several drawbacks, including increased size, weight, power consumption, and limited space for installation. These issues hinder the development of miniaturized and lightweight satellites. Fifth, microscopic fusion welding phenomena; Magnetic latching relay contacts are highly susceptible to arc erosion and metal migration under high current or frequent switching conditions. Due to the sudden increase in local temperature on the contact surface, microscopic welding occurs in the contact material, leading to contact adhesion and failure to disconnect. This defect is an inherent physical characteristic of mechanical electromagnetic relays. Even by optimizing the contact material or reducing the operating frequency, the risk of adhesion under high current loads cannot be completely eliminated, resulting in continuous energization of the load and, in severe cases, overcurrent damage to spaceborne equipment.

[0019] Sixth, the effects of aging are significant; Magnetic latching relays rely on direct metal contact for conduction. Their contact resistance is significantly affected by contact pressure, surface oxidation, and aging in a thermal vacuum environment. Since the contact resistance is typically higher than the on-resistance of semiconductor power devices, the power supply path impedance increases accordingly, leading to a significant increase in line voltage drop and Joule heat loss. This defect results in reduced power distribution efficiency, and prolonged heating in the contact area accelerates the aging of the insulation material, weakening the overall electrical insulation strength.

[0020] 7. Traditional single-relay control schemes lack redundancy isolation mechanisms; If the relay's internal coil drive fails, the mechanical armature jams, or a short circuit occurs at the contact, the power control link will lose its unidirectional controllability. Due to the lack of a backup disconnect path, the load cannot be reliably de-energized, and fault isolation capability is completely lost. This defect manifests as a systemic failure in a single-point-of-failure model; even software monitoring cannot restore hardware-level electrical isolation, severely restricting the safety of long-term on-orbit operation of the satellite.

[0021] Therefore, the existing power switching method of magnetic latching relays that directly carry load current cannot simultaneously meet the design requirements of satellite systems for high reliability, low loss, miniaturization, and long life.

[0022] To address the aforementioned issues, a novel application method for magnetic latching relays is needed to prevent them from directly carrying high-power load currents while maintaining their advantages such as low power consumption, electrical isolation, and reliable holding, thereby improving the reliability of satellite power switching systems.

[0023] This invention moves the magnetic latching relay from the main power circuit to the control circuit, so that its contacts are used only to output control signals to drive the gate of the MOS power switch. The MOS power switch module is located between the satellite power bus and the load, specifically employing a redundant "two-parallel, two-series" topology composed of two parallel MOS groups connected in series. Given that the relay contact operating current is reduced from the ampere level to the milliampere level, the potential for contact erosion and lifespan degradation caused by high-current direct drive is fundamentally eliminated. The parallel structure shares the load current, effectively improving conduction reliability and heat dissipation, while the series structure creates a dual-break path, significantly enhancing turn-off isolation capability, thereby improving the satellite power system's resistance to single-point failures and long-term on-orbit reliability. Through the high-impedance input characteristics of the MOS device gate, the current stress on the magnetic latching relay contacts is significantly reduced, achieving electromechanical decoupling. When a single transistor experiences increased on-resistance or performance degradation, the parallel branch can maintain the current path; if a single transistor experiences drain-source breakdown or turn-off failure, the series branch can still provide electrical isolation. Through the combination of topological redundancy and electromechanical separation, dual reliable protection for power path conduction and turn-off is achieved.

[0024] This invention incorporates a gate drive and protection module between the magnetic latching relay contact output and the MOS power switch control terminal. This module integrates a gate current-limiting resistor, a gate pull-down resistor, a voltage regulator, and a transient suppression device. It limits the peak gate charging current, accelerates gate charge discharge during turn-off, suppresses voltage spikes and electrostatic interference, and prevents MOS gate oxide layer breakdown, thereby improving the stability and anti-interference margin of the power switch operation. The MOS gate capacitance is prone to inrush current and voltage overshoot during rapid charging and discharging. The current-limiting resistor in series suppresses the rate of change of current and voltage. The pull-down resistor provides a defined low-potential reference path for the turn-off state. The voltage regulator and transient suppression devices dissipate parasitic energy based on clamping or absorption principles, thus ensuring the integrity of the gate drive signal.

[0025] This invention uses a positive pulse to drive the magnetic latching relay to close in order to apply the gate turn-on voltage, and then uses a reverse pulse to drive the relay to open and cut off the gate power supply, and completes the MOS turn-off reset in conjunction with a pull-down resistor.

[0026] Technical benefits: This technology achieves zero-power relay contact holding and precise synchronous switching of MOS switch states, reducing static power consumption at the control end and preventing false triggering caused by gate floating. Due to the hysteresis characteristics of the magnetic latching relay, only an instantaneous pulse is needed to reverse the core magnetization direction and maintain the contact state, thereby achieving low-power control. Since the contacts maintain their original state after the pulse ends, the gate voltage is stably maintained. When a reverse pulse triggers the contacts to open, the gate charge is discharged through the pull-down path, thus completing reliable on / off timing control.

[0027] This invention utilizes a small magnetic latching relay to handle low-current control tasks, and combines it with multiple standard-packaged MOS devices to construct a high-current power path, replacing the traditional single high-capacity magnetic latching relay direct-drive solution. This significantly reduces the overall size and weight of the power switching module, decreases the procurement cost of high-capacity relays, and facilitates space layout and lightweight integration on satellite platforms. Relay size and weight typically increase non-linearly with rated current carrying capacity. By transferring the current-carrying task to semiconductor power devices, the relay specifications only need to match the gate drive current, thereby enabling derating selection of electromechanical components and a compact system-level structure. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall architecture of a satellite power switching circuit according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the magnetic latching relay control module of the satellite power switching circuit in one embodiment of the present invention; Figure 3 This is a schematic diagram of the MOS power switch module, gate drive and protection module of the satellite power switching circuit in one embodiment of the present invention. Detailed Implementation

[0029] In this invention, the various embodiments are merely intended to illustrate the solutions of the invention and should not be construed as limiting.

[0030] It should also be noted that within the scope of this invention, the terms "same", "equal", and "equal to" do not mean that the two values ​​are absolutely equal, but allow for a certain reasonable error. In other words, the terms also cover "substantially the same", "substantially equal", and "substantially equal to".

[0031] Furthermore, the numbering of the steps in the methods of the present invention does not limit the execution order of the method steps. Unless otherwise specified, the method steps may be executed in different orders.

[0032] The satellite power switching circuit and its operation method proposed in this invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of this invention will become clearer from the following description and claims. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of this invention.

[0033] In this invention, the modules of the system according to the invention can be implemented using software, hardware, firmware, or a combination thereof. When a module is implemented using software, its function can be implemented through computer program flow. For example, the module can be implemented using code segments (such as code segments in languages ​​like C and C++) stored in a storage device (such as a hard disk, memory, etc.), wherein the corresponding function of the module can be implemented when the code segment is executed by a processor. When a module is implemented using hardware, its function can be implemented by setting a corresponding hardware structure. For example, the module's function can be implemented by hardware programming a programmable device such as a field-programmable gate array (FPGA), or by designing an application-specific integrated circuit (ASIC) that includes multiple transistors, resistors, capacitors, and other electronic devices. When a module is implemented using firmware, the module's function can be written into a read-only memory such as an EPROM or EEPROM in the form of program code, and the corresponding function of the module can be implemented when the program code is executed by a processor. In addition, some functions of the module may need to be implemented by separate hardware or by working in cooperation with the hardware. For example, the detection function is implemented by a corresponding sensor (such as a proximity sensor, accelerometer, gyroscope, etc.), the signal transmission function is implemented by a corresponding communication device (such as a Bluetooth device, infrared communication device, baseband communication device, Wi-Fi communication device, etc.), the output function is implemented by a corresponding output device (such as a display, speaker, etc.), and so on.

[0034] This invention relates to the field of spacecraft power management and reliability control technology, specifically to a high-reliability switching circuit for satellite power supply based on a magnetic latching relay controlling a MOS power switch. This circuit enables reliable connection and disconnection of power supply to satellite loads, reducing the risks of sticking and mid-position failure caused by high current operation of the magnetic latching relay contacts.

[0035] The technical problems to be solved by this invention include: 1. The problem of contact adhesion failure caused by high current operation of magnetic latching relays: In existing designs, the relay contacts directly carry the load current. During load startup or shutdown, the large inrush current can easily cause arcing between the contacts, raising the contact surface temperature and causing the contact material to melt and adhere. When the satellite needs to perform a load power-off operation, the relay may fail to disconnect properly, resulting in continuous power supply to the load and affecting satellite fault isolation and safety control.

[0036] Second, the problem of mid-position failure caused by long-term load on the mechanical structure of magnetic latching relays: Magnetic latching relays rely on the position of mechanical contacts to maintain the on-off state. When the contacts are subjected to large current and thermal stress for a long time, it is easy to cause contact wear, spring fatigue and mechanical structure displacement, which makes the relay unable to maintain a stable fully closed or fully open state. Mid-position failure problems such as abnormally increased contact resistance and uncertain output state occur, reducing the reliability of satellite power system.

[0037] Third, the problem of increased system voltage drop and power loss caused by current passing through relay contacts: Due to the contact resistance of magnetic latching relay contacts, when the load current is large, according to the Joule heating effect, the relay will generate a large conduction loss, and at the same time generate a voltage drop, resulting in a decrease in the load voltage, a decrease in system efficiency, and an increase in the temperature rise of the relay itself, which is not conducive to thermal design in the long-term operation environment of satellites.

[0038] Fourth, address the issues of increased size, weight, and cost of high-power magnetic latching relays: To meet the demands of high-current loads, existing solutions require the use of magnetic latching relays with higher rated currents. However, high-specification relays are typically larger and heavier, and space-grade components are also more expensive, which is not conducive to the development of lightweight and miniaturized satellite platforms.

[0039] Fifth, address the issue of insufficient reliability in power switching during long-term satellite operation: Satellites typically need to meet the requirements of years of on-orbit operation, necessitating power switching devices with extremely high reliability and long lifespan. Existing magnetic latching relays directly handle power switching, making the mechanical contacts a weak point in the entire power supply chain and reducing the fault tolerance of the satellite power system.

[0040] Therefore, a new satellite power switching technology is needed to eliminate the need for magnetic latching relays to handle high-current load switching, allowing them to function solely as control devices. Reliable semiconductor power switches facilitate load power switching, thereby reducing the stress on the relay contacts and improving the reliability, lifespan, and power efficiency of the satellite power system. The purpose of this invention is to provide a satellite power switching circuit and its operation method to address the low reliability issue caused by existing magnetic latching relays simultaneously handling control and power switching.

[0041] To achieve the above objectives, the present invention provides a satellite power switching circuit and its operation method, comprising: a magnetic latching relay controller configured to provide a magnetic latching relay on / off signal; magnetic latching relay contacts configured to generate a control signal for a MOS power switch module based on the magnetic latching relay on / off signal, and to provide the control signal of the MOS power switch module to the MOS power switch module; and a MOS power switch module configured to open or close the current path between the satellite power bus and the load power supply module based on the control signal of the MOS power switch module.

[0042] Figure 1 The overall architecture of a satellite power switching circuit according to an embodiment of the present invention is shown, such as... Figure 1 As shown, this invention proposes a high-reliability switching circuit for satellite power supply based on a magnetic latching relay controlling a MOS power switch. By combining the magnetic latching relay with the MOS power switch, the traditional working mode of the magnetic latching relay directly carrying the load power current is changed to a low-current control mode. At the same time, a redundant series-parallel structure of multiple MOS devices is adopted to improve the reliability of power supply on / off control.

[0043] The circuit includes: a magnetic latching relay control module (including a magnetic latching relay controller and magnetic latching relay contacts), a MOS power switch module, a gate drive and protection module, and a load power supply module. The magnetic latching relay controller is divided into a first main control branch 1 and a second standby control branch 3. The first main control branch provides on / off signals for the first set of magnetic latching relay contacts; the second standby control branch provides on / off signals for the second set of magnetic latching relay contacts; the first set of magnetic latching relay contacts provides control signals for the first MOS power switch module 2; and the second set of magnetic latching relay contacts provides control signals for the second MOS power switch module 4. When the satellite controller issues a load power-on command or a load power-off command, if the first main control branch, the first set of magnetic latching relay contacts, or the first MOS power switch module malfunctions, the second standby control branch receives the power-on control signal or outputs a reverse drive pulse; the second set of magnetic latching relay contacts changes from an open state to a closed state; thus, the satellite achieves dual-machine redundancy.

[0044] In one embodiment of the present invention, the first host control branch includes a first parallel control branch ( Figure 1 The left-hand instruction main switch (standby switch) and the second parallel control branch ( Figure 1 The left-hand side of the instruction is for main operation (standby operation); and the second standby control branch includes the third parallel control branch ( Figure 1 The instruction main switch (standby switch) on the right side and the fourth parallel control branch ( Figure 1The instruction on the right side is to open the main circuit (or close the backup circuit); the first parallel control branch controls the first magnetic latching relay contact ( Figure 1 The relay 1) normally closed and the second magnetic latching relay contact ( Figure 1 The relay 2) is normally open; the second parallel control branch controls the first magnetic latching relay contact to be normally open and the second magnetic latching relay contact to be normally closed; the third parallel control branch controls the third magnetic latching relay contact ( Figure 1 3) Normally open and fourth magnetic latching relay contacts ( Figure 1 The relay 4) is normally closed; the fourth parallel control branch controls the fourth magnetic latching relay contact to be normally closed and the third magnetic latching relay contact to be normally open.

[0045] When the satellite controller issues a load power-on command, the first parallel control branch controls the second magnetic latching relay contact to be normally open, and the second parallel control branch controls the first magnetic latching relay contact to be normally open. Therefore, even if the signal of the first parallel control branch is blocked or the normally open contact of the second magnetic latching relay fails, the second parallel control branch will still control the first magnetic latching relay contact to be normally open, thus achieving redundant power-on. Similarly, when the satellite controller issues a load power-off command, the first parallel control branch controls the first magnetic latching relay contact to be normally closed, and the second parallel control branch controls the second magnetic latching relay contact to be normally closed, thus achieving redundant disconnection of the system.

[0046] Figure 2 This invention illustrates a magnetic latching relay control module for a satellite power switching circuit according to an embodiment of the present invention. The operation of the magnetic latching relay control module is as follows: The magnetic latching relay switches its contact state by receiving positive or negative pulses output from the controller. Unlike traditional technologies where the magnetic latching relay is directly connected in series with the main power circuit, in this invention, the magnetic latching relay contacts no longer bear the task of switching the large current on the load side, but are only used to output control signals for the MOS power switch. The magnetic latching relay contacts are connected to the gate control terminal of the MOS power switch, and the load power supply is switched on and off by controlling the MOS gate voltage. Because the MOS gate has a high-impedance input, the relay contact operating current is reduced from the traditional ampere level to the milliampere level, fundamentally reducing the current stress on the relay contacts.

[0047] Figure 3 This invention illustrates a satellite power switching circuit MOS power switch module, gate drive, and protection module according to an embodiment of the present invention, such as... Figure 3 As shown, the MOS power switch module is positioned between the satellite power bus and the load to handle the actual load operating current. The MOS power switch module employs a two-series, two-parallel redundant structure design. Two MOS devices are connected in parallel along the same path to improve the turn-on reliability of the MOS power switch. The parallel connection of the two MOS devices allows the load current to be shared by multiple MOS devices. When a single MOS device experiences: When on-resistance increases, current capability decreases, and local performance degrades, the other parallel MOS can still handle part of the load current, preventing single-point failure from causing system power supply anomalies. Simultaneously, the parallel MOS structure reduces the on-current, junction temperature, and thermal stress of individual MOS devices, improving long-term device lifespan.

[0048] The power path employs two MOSFETs connected in series to improve load power-off reliability. The two MOSFETs, connected in series, form a dual-disconnect path: power supply → MOSFET_A → MOSFET_B → load. During a power-off operation, both MOSFETs simultaneously turn off, providing complete isolation. Compared to a single-MOSFET turn-off structure, this design avoids the problems associated with a single MOSFET, such as drain-source breakdown, increased turn-off leakage current, and single-MOSFET failure leading to short circuits that prevent load power disconnection. Even if one MOSFET fails due to a short circuit, the other MOSFET maintains its power isolation capability, improving the satellite load fault clearing capability.

[0049] In one embodiment of the present invention, such as Figures 2-3 As shown, the MOS gate drive and protection module is connected between the magnetic latching relay contact output terminal and the MOS power switch control terminal, and includes: a gate current limiting resistor, a gate pull-down resistor, a voltage regulation protection device, and a transient suppression protection device.

[0050] This invention controls the MOS power switch using a magnetic latching relay and employs a redundant MOS structure with two series and two parallel connections. This transforms the magnetic latching relay contacts from an ampere-level power path to a milliampere-level control path, effectively reducing the risk of contact sticking and mid-position failure. Simultaneously, by utilizing the low on-resistance and series-parallel redundancy characteristics of the MOS, it improves the conduction capability, turn-off reliability, and fault tolerance during power switching, thus achieving a highly reliable power switching solution suitable for long-term on-orbit operation of satellites.

[0051] (1) Significantly reduces the risk of contact adhesion failure in magnetic latching relays and improves relay service life. This invention changes the traditional working method of magnetic latching relays being directly connected in series in the main power circuit and bearing the large current switching of the load. It converts the magnetic latching relay into a low-power control device, which is only used to control the conduction and shutdown of MOS power switches.

[0052] Since the magnetic latching relay contacts no longer carry ampere-level current on the load side, but only milliampere-level control current, the arc energy generated by the contacts during operation is significantly reduced, while reducing contact erosion, material migration, and contact welding phenomena.

[0053] Therefore, the present invention can effectively reduce the contact sticking failure of magnetic latching relays caused by high current impact, and improve the long-term reliability and on-rail service life of the relay.

[0054] (2) Reduce the probability of failure of the magnetic latching relay in the middle position and improve the reliability of state holding. In the prior art, when the contacts of a magnetic latching relay are subjected to a large current for a long time, they will generate large thermal and mechanical stresses, which can easily lead to contact deformation, spring fatigue and mechanical structure misalignment, making it impossible for the relay to stably maintain a fully closed or fully open state.

[0055] This invention reduces the operating current of the relay contacts, thus preventing the relay's mechanical structure from being affected by the thermal shock generated by the large current, reducing the risk of contact erosion and mechanical deformation, thereby reducing the probability of the relay being in an uncertain or intermediate state and improving the reliability of power switching.

[0056] (3) Improve the reliability of power switch conduction and reduce system conduction loss. This invention uses MOS power switches to replace magnetic latching relays to handle load current, and employs two MOS devices connected in parallel to form a conduction path. The parallel MOS structure allows the load current to be shared by multiple power devices, reducing the on-state current and junction temperature of a single MOS device and improving the device's current margin. Simultaneously, because the on-resistance of MOS devices is lower than the contact resistance of traditional relay contacts, the power supply path impedance is reduced, thereby reducing power line voltage drop, power loss, and device heat generation, and improving the efficiency of the satellite power system.

[0057] (4) Improve load power failure reliability and enhance fault isolation capability. This invention employs two MOS devices connected in series to form a power shutdown path. When a load power-off operation is performed, both series-connected MOS devices must be turned off simultaneously to achieve effective power isolation. Compared to the traditional single-relay disconnection method, this solution reduces the risk of load failure due to the failure of a single power device. Even if one MOS device experiences drain-source breakdown, turn-off failure, or increased leakage current, the other series-connected MOS device can still provide electrical isolation, improving the reliability of load disconnection.

[0058] (5) Improve the redundancy of power paths and the ability to resist single point of failure. This invention employs a "two parallel and two series" MOS redundancy structure: two MOS transistors are connected in parallel to improve conduction capability; The two MOSFETs are connected in series to improve turn-off capability. This structure simultaneously enhances current carrying capacity, thermal reliability, electrical isolation, and fault tolerance. It reduces the impact of a single device failure on the entire power control chain.

[0059] (6) Reduce system weight, size and design complexity Traditional solutions require the use of large-capacity magnetic latching relays to meet the demands of high-current loads, which increases the size, weight, and cost of the devices.

[0060] This invention uses a small magnetic latching relay in conjunction with a MOS power device to achieve high current switching, which can reduce the relay specification requirements while meeting high reliability requirements, and is conducive to the miniaturization and lightweight design of satellite platforms.

[0061] (7) Improve the reliability of satellites during long-term on-orbit operation This invention forms a highly reliable power switching structure that combines electromechanical components by using a magnetic latching relay for low current control, MOS power devices for execution, two parallel circuits to improve turn-on reliability, and two series circuits to improve turn-off reliability.

[0062] Compared to the traditional method of directly switching the load power supply using magnetic latching relays, this invention reduces the use of mechanical contacts as high-power switching devices, thereby improving the reliability of satellite power distribution systems in long-term space environments.

[0063] The present invention also provides a switching operation process for a satellite power switching circuit, including: (1) During the power-on process, when the controller sends a load power-on command: ① The magnetic latching relay operates; ② The relay contacts output a high-level control signal; ③ The gates of the two series and two parallel MOS transistors obtain the turn-on voltage; ④ Multiple MOS transistors conduct simultaneously; ⑤ The power supply supplies power to the load through the MOS power path. During this process: the magnetic latching relay only carries mA-level control current. The MOS transistors carry A-level load current.

[0064] (2) During the power-off process, when the controller sends a power-off command: ① the magnetic latching relay reverses; ② the MOS gate drive voltage is released; ③ all series MOS transistors are turned off; ④ the power supply output is isolated from the load. Due to the use of a dual-series MOS structure, the reliability of power-off isolation is improved.

[0065] One embodiment of the present invention provides a high-reliability satellite power switching circuit based on a magnetic latching relay controlling a MOS power switch. This circuit is applied to a satellite power distribution unit to achieve reliable power-on and power-off control of onboard load equipment. It comprises a magnetic latching relay control unit, a MOS power switch unit, and a MOS gate drive and protection unit. The magnetic latching relay control unit outputs control signals to the MOS power switch, and the MOS power switch unit handles the actual operating current on the load side.

[0066] The magnetic latching relay control unit includes a magnetic latching relay and a relay drive circuit. The satellite's onboard computer or power management controller outputs control commands, which, via the relay drive circuit, generate forward or reverse drive pulses, causing the magnetic latching relay to switch contact states. Unlike traditional magnetic latching relays that are directly connected in series in the power output circuit, the contacts of the magnetic latching relay in this invention are not connected to the main power circuit of the load, but rather to the gate control terminal of the MOS power switch. When the relay contacts are closed, a gate drive voltage is provided to the MOS power switch; when the relay contacts are open, the gate of the MOS power switch is in the off state. Due to the high input impedance of the MOS gate, the relay contacts only need to provide milliampere-level control current. Therefore, the operating current of the magnetic latching relay contacts is reduced from the ampere level in conventional solutions to the milliampere level.

[0067] The MOS power switching unit adopts a "two-series, two-parallel" redundant structure. Specifically, it includes a first parallel MOS group and a second parallel MOS group, with the two groups of MOS connected in series to form the main power path. Each parallel MOS group includes two MOS power transistors.

[0068] When the satellite controller issues a load power-on command, the magnetic latching relay drive circuit receives the power-on control signal. The drive circuit outputs a positive pulse, causing the magnetic latching relay to actuate. The magnetic latching relay contacts change from the open state to the closed state. The relay contacts output a control voltage, which is applied to the gate of the MOS power transistor via the gate drive resistor. The gate of the MOS power switch receives the turn-on voltage. Both sets of parallel MOS transistors simultaneously enter the conducting state, and the satellite bus power supply supplies power to the load through the MOS power path. At this time, the magnetic latching relay only carries the gate control current, with a current rating of mA; the MOS power switch carries the load's A-level operating current, acting as the actual power actuator.

[0069] During load power supply, the two parallel MOSFETs share the load current. By using two MOSFETs in parallel, each MOSFET bears the load current on an average basis, which reduces conduction current, power loss, chip junction temperature, and thermal stress compared to operating with a single MOSFET. Furthermore, if one MOSFET experiences increased on-resistance, performance degradation, or decreased current capability, the other parallel MOSFET can still maintain the power supply path, improving the system's resilience to single-point failures.

[0070] When the satellite controller issues a load power-off command, the magnetic latching relay drive circuit outputs a reverse drive pulse. This reverses the magnetic latching relay, restoring the relay contacts to the open state and cutting off the MOS gate drive voltage. Simultaneously, the MOS gate charge is released through the gate pull-down resistor. The gate-source voltage of the MOS power transistor decreases. All MOS devices are turned off, the series MOS group is simultaneously cut off, and the load is electrically isolated from the satellite bus power supply.

[0071] This embodiment uses two MOS transistors connected in series to form a power-off isolation path. Compared to a single MOS turn-off structure, if a single MOS transistor experiences drain-source breakdown, turn-off failure, or an abnormal increase in leakage current, the load may not be completely de-energized. However, with a dual-string MOS structure, even if one MOS transistor fails, the other can still provide isolation. Therefore, it improves the reliability of load power-off and fault isolation capabilities.

[0072] Through the above embodiments, the present invention achieves: (1) The magnetic latching relay is removed from the high current power path, reducing the risk of contact sticking; the relay current Irelay is improved from A level to mA level, and the current is reduced by 100 to 1000 times.

[0073] (2) Reduce thermal shock of relay contacts and reduce mid-position failure; power consumption: When the relay contacts are connected to the main power circuit of the load, taking a working current of 5A and a relay on-resistance RCONTACT = 50mΩ as an example, the relay heat dissipation = 52 * 0.05 = 1.25W. When the relay is removed from the high-current power path and is only used to control the conduction of the MOS power switch, the current is in the mA range. Taking 5mA as an example, the relay heat dissipation = 0.0052 * 0.05 = 1.25 * 10-6W, and the heat dissipation is significantly reduced.

[0074] (3) Use the low on-resistance of MOS to reduce the supply voltage drop; the on-resistance of the relay RCONTACT = tens of mΩ, the on-resistance of MOS RDS(ON) = mΩ level. Taking RCONTACT = 50mΩ, RDS(ON) = 5 mΩ, and the working current 5A as an example, Vdrop = I×Rc, the supply voltage drop is reduced from 0.25V to 0.025V, a reduction of 10 times.

[0075] (4) Improve conduction capability and thermal reliability through a MOS dual-parallel structure; single MOS Dual MOS in parallel: Reduce single-tube current stress by 50%.

[0076] (5) Improve turn-off isolation capability through a two-string MOS structure; (6) A highly reliable satellite power switching architecture of "mechanical control + semiconductor power execution" is formed.

[0077] This solution is applicable to satellite power distribution units, payload power supply control modules, satellite management systems, and other spacecraft electronic equipment that require highly reliable power switching.

[0078] In view of the technical defects of existing magnetic latching relays, such as contact sticking, high contact resistance leading to increased losses, and single-point failure causing the load to be unable to be disconnected and isolated during high current switching, the present invention aims to provide a high-reliability switching circuit for satellite power supply based on magnetic latching relay controlling MOS power switch, so as to solve the problems of high conduction loss, insufficient turn-off reliability and weak resistance to single-point failure during satellite load power supply switching.

[0079] Thanks to the invention's use of MOS power switches instead of magnetic latching relays to handle load current, and the parallel connection of two MOS devices to form a conduction path, the load current can be shared by multiple power devices, reducing the on-state current and junction temperature of a single MOS device and improving the device's current margin. Simultaneously, since the on-resistance of MOS devices is lower than the contact resistance of traditional relay contacts, the power supply path impedance can be reduced, thereby reducing power line voltage drop, power loss, and device heat generation, and improving the efficiency of the satellite power system.

[0080] By using two MOSFETs connected in series to form a power shutdown path, both series-connected MOSFETs must be turned off simultaneously to achieve effective power isolation during load disconnection. Compared to the traditional single-relay disconnection method, this solution reduces the risk of load failure due to the failure of a single power device. Even if one MOSFET experiences drain-source breakdown, turn-off failure, or increased leakage current, the other series-connected MOSFET can still provide electrical isolation, improving load disconnection reliability.

[0081] To improve system fault tolerance, this invention employs a redundant MOS structure with two parallel and two series connections. This structure simultaneously enhances current carrying capacity, thermal reliability, electrical isolation, and fault tolerance, reducing the impact of a single device failure on the entire power control chain.

[0082] Traditional solutions require large-capacity magnetic latching relays to meet high-current load demands, leading to increased device size, weight, and cost. This invention utilizes a miniature magnetic latching relay combined with MOS power devices to achieve high-current switching. This reduces relay specifications while maintaining high reliability, facilitating miniaturization and lightweight design of the satellite platform. In summary, this invention achieves a highly reliable electromechanical power switching structure through low-current control with a magnetic latching relay, execution with MOS power devices, improved turn-on reliability with two parallel connections, and improved turn-off reliability with two series connections, significantly improving the long-term on-orbit reliability of the satellite.

[0083] Figure 1This is a schematic diagram of the overall topology of the high-reliability switching circuit for satellite power supply based on a magnetically latched relay controlling a MOS power switch, as described in this invention. Given the extremely high reliability requirements of the power distribution link for satellite platforms, this invention adopts a hybrid electromechanical switching architecture. The magnetically latched relay handles low-current control signal switching, while the MOS power switch array handles high-current load switching, thereby effectively avoiding physical damage to mechanical contacts under high-current conditions. Figure 1 As shown, a power switch array is connected in series between the power input terminal and the load output terminal. The power switch array includes a composite topology of parallel conduction branches and series shutdown branches. Specifically, the first MOS switch and the second MOS switch are connected in parallel between the power input terminal and the intermediate node, forming a parallel conduction branch; the third MOS switch and the fourth MOS switch are connected in parallel between the intermediate node and the load output terminal, forming another set of parallel conduction branches; the first MOS switch and the third MOS switch are connected in series, and the second MOS switch and the fourth MOS switch are connected in series, thereby forming a global power path of two parallel and two series. When the load is powered on, the magnetic latching control module outputs a closing command, the magnetic latching relay contacts close, and the drive signal is transmitted to the gates of each MOS switch via the MOS gate drive and protection module, so that the first MOS switch to the fourth MOS switch is turned on simultaneously. The current is shunted from the power input terminal through the parallel path and then converged to the load output terminal through the series path. Due to the parallel structure, the total load current is evenly distributed across multiple branches, significantly reducing the on-current density of individual MOS switches and slowing the junction temperature rise rate, thus effectively alleviating device thermal stress. When a load power-off operation is performed, the magnetic latching relay contacts open, the drive signal is cut off, and the gate voltage of each MOS switch drops below the threshold. The turn-off paths of the first and third MOS switches, and the second and fourth MOS switches, simultaneously establish a high-impedance state. Even if one MOS switch experiences drain-source breakdown or increased turn-off leakage, the other series-connected MOS switch can maintain a complete isolation potential, achieving double-disconnect redundancy protection. The drive coil of the magnetic latching control module is powered by the upper-board controller through a low-current control line. The control current is typically controlled in the tens of milliamps range, far below the load operating current. Therefore, the magnetic latching relay contacts only perform signal-level switching functions, completely eliminating the high-current arc environment, resulting in a substantial improvement in contact life and reliability. Furthermore, the PCB layout of the power switch array employs symmetrical traces and a large-area copper plating design for heat dissipation. This ensures uniform current distribution and utilizes satellite structural components as auxiliary heat dissipation surfaces, further reducing system thermal resistance. This topology not only meets the high-current switching requirements of satellite loads but also significantly reduces the impact of single-point failures on the power link through device redundancy and current shunting mechanisms, providing highly robust power supply protection for onboard equipment.

[0084] Figure 2This is a schematic diagram showing the partial circuit connection details of the MOS gate drive and protection module described in this invention. To ensure the integrity of the MOS power switch gate drive signal and its anti-interference capability, this invention adds a dedicated drive and protection network between the magnetic latching relay contact output terminal and the MOS power switch control terminal to cope with transient voltage fluctuations and signal attenuation in complex electromagnetic environments. Figure 2 As shown, the MOS gate drive and protection module is directly connected in series between the output terminal of the magnetic latching relay contact and the gate pin of the MOS switch. Internally, it includes a gate current-limiting resistor, a gate pull-down resistor, a voltage regulator, and a transient suppression protection device. When the magnetic latching relay contact closes, the drive voltage is transmitted through the contact to the gate current-limiting resistor. This resistor primarily limits the peak current during gate charging, preventing micro-cracks or dielectric breakdown in the gate oxide layer due to excessive surge current. Simultaneously, it works with the PCB parasitic inductance to form a damping network, suppressing gate voltage oscillations. The gate pull-down resistor is connected in parallel between the gate and source of the MOS switch. When the magnetic latching relay contact opens or the drive signal is lost, it provides a defined discharge path for the gate junction capacitance, ensuring the gate voltage quickly drops below the turn-off threshold and preventing the MOS switch from being accidentally turned on due to residual charge. The voltage regulator and protection device employs a bidirectional Zener diode structure, connected between the gate and source reference ground. When the drive circuit experiences overvoltage due to electrostatic discharge or lightning strike, the Zener diode immediately conducts and clamps, limiting the gate-source voltage within a safe window, thereby protecting the gate insulation layer from high-voltage breakdown. The transient suppression protection device preferably uses a TVS diode, connected in series or parallel in the signal transmission path. It rapidly absorbs nanosecond-level high-energy pulses, converting transient energy into heat dissipation, preventing damage to the drive chip or the internal circuitry of the MOS gate. When the system is in standby or power-off holding state, the pull-down resistor works in conjunction with the Zener diode to maintain a stable gate potential, preventing malfunctions caused by single-event upsets due to space radiation. Furthermore, all protection devices are radiation-hardened models and employ SMT mounting technology to reduce the impact of parasitic parameters on high-frequency drive signals. Through the introduction of this drive and protection module, the switching speed, interference immunity margin, and long-term operational stability of the MOS switch are significantly enhanced, ensuring accurate control signal transmission and reliable power device response even in complex electromagnetic coupling environments.

[0085] The control flow begins with the upper-board controller receiving a load management command. The controller then verifies the load status and power bus voltage. Once the power-on conditions are met, the controller outputs a high-level trigger signal to the magnetic latching control module. The magnetic latching relay coil generates a magnetic field under the action of a pulsed current, driving the armature to close and hold the magnetic latching relay contacts. Within a microsecond delay after the contact closure, the drive signal is transmitted to the power switch array through the MOS gate drive and protection module. The gate voltages of the first to fourth MOS switches gradually increase. When the voltage exceeds a threshold, a channel is formed, and a power path is established. Due to the current-sharing characteristics of the parallel structure, the load current rises smoothly, avoiding surge impact. When the system executes a power-off command, the controller outputs a reverse pulse or cuts off the holding signal, and the magnetic latching relay contacts quickly open, physically cutting off the drive path. At this time, the gate pull-down resistor immediately begins to discharge the gate charge, and the channels of each MOS switch are gradually pinched off, with the drain-source current decaying to the microampere level. If an abnormal turn-off of a certain MOS switch is detected, the control system can trigger redundant bypass isolation or report a fault code to ensure that the load side is completely disconnected from the power supply. When the system encounters command loss or bus communication interruption, the power-off retention characteristic of the magnetic latching relay, together with the MOS gate pull-down network, maintains the circuit in a safe off state, preventing damage to the equipment caused by accidental power-on. This timing logic not only ensures the smoothness of the switching process, but also achieves a highly reliable power management closed loop through a dual mechanism of hardware-level physical isolation and software-level state verification, fully meeting the stringent control requirements of long-term on-orbit satellite operation.

[0086] This invention effectively overcomes the inherent defects of traditional magnetic latching relays in satellite power switching applications through a triple-redundant system-level design of topology reconstruction, device redundancy, relay drive protection, and timing control. The coordinated operation of the components retains the static low power consumption and radiation resistance advantages of electromagnetic relays while fully leveraging the low impedance and fast response characteristics of MOS power switches, thereby constructing a spaceborne power switching circuit that combines high conduction efficiency, strong turn-off isolation capability, and excellent fault tolerance. Those skilled in the art can make equivalent substitutions or optimizations to the device parameters, layout routing, and protection thresholds according to the current level, heat dissipation conditions, and space constraints of the actual satellite platform. Such modifications are all within the scope of this invention and do not depart from the protective essence of this invention.

[0087] A satellite power switching control method based on magnetic latching relay controlling MOS power switches in one embodiment of the present invention includes: an upper board position controller receiving a load management command and verifying the load status and power bus voltage; after verification, the upper board position controller outputs a trigger pulse to the magnetic latching control module; the magnetic latching control module receives the trigger pulse, drives the magnetic latching relay contacts to close and hold; after the magnetic latching relay contacts close, the drive signal is transmitted to the power switch array via the MOS gate drive and protection module; the power switch array receives the drive signal, and the first MOS switch, the second MOS switch, the third MOS switch, and the fourth MOS switch are simultaneously turned on, establishing a conduction path between the power input terminal and the load output terminal; the upper board position controller receives a power-off command and outputs a reverse pulse or cuts off the holding signal; the magnetic latching control module receives the power-off command, and the magnetic latching relay contacts open; the MOS gate drive and protection module cuts off the drive voltage output, and the gate charge is discharged through the pull-down resistor; each MOS switch in the power switch array is turned off, and the turn-off paths of the first MOS switch and the third MOS switch, and the turn-off paths of the second MOS switch and the fourth MOS switch, simultaneously establish a high-impedance state, isolating the power input terminal and the load output terminal.

[0088] The steps for the upper-board controller to verify the load status and power bus voltage include: Step 1, acquiring the real-time power bus voltage value and comparing it with a preset safety threshold; Step 2, reading the load-side current sensor data to determine if a short circuit or overcurrent condition exists; Step 3, generating a high-level trigger signal when the comparison results all meet the conduction conditions. During the power switch array conduction process, the rise rate of the gate voltage of the first and second MOS switches is limited by the gate current-limiting resistor, and the transient suppression protection device absorbs nanosecond-level voltage spikes on the drive circuit. The system also includes a fault monitoring step, acquiring the drain-source voltage of each MOS switch in real time. When an abnormal drop in the drain-source voltage of a single MOS switch is detected, it is determined that a short circuit failure has occurred in that branch. The control system records the faulty branch number and maintains the remaining branches in a turned-off state.

[0089] This invention discloses a high-reliability switching circuit and control method for satellite power supplies based on a magnetic latching relay controlling a MOS power switch, relating to the field of spacecraft power management technology. Addressing the problems of existing magnetic latching relays, such as contact sticking during high-current switching, high contact resistance leading to increased losses, and single-point failures preventing load isolation, this invention employs a magnetic latching relay to handle low-current control signal switching. The power switch array uses a two-parallel, two-series MOS topology to form the power on / off path. Parallel branches share the conduction current to reduce thermal stress, while series branches form a double-disconnection isolation mechanism. The MOS gate drive and protection module includes current limiting, pull-down, voltage regulation, and transient suppression devices to ensure the integrity of the drive signal. This method achieves smooth power-on and reliable power-off through timing logic control. This invention effectively reduces conduction losses, improves turn-off redundancy and resistance to single-point failures, and balances lightweight design with long-term on-orbit reliability, making it suitable for power distribution and fault isolation scenarios for spaceborne equipment.

[0090] While some embodiments of the present invention have been described in this application, those skilled in the art will understand that these embodiments are merely illustrative. Numerous variations, alternatives, and improvements will arise in those skilled in the art under the teachings of this invention without departing from its scope. The appended claims are intended to define the scope of the invention and thereby cover the methods and structures within the scope of the claims themselves and their equivalents in power conversion.

Claims

1. A satellite power switching circuit, characterized in that, include: The magnetic latching relay controller is configured to provide on / off signals for the magnetic latching relay; The magnetic latching relay contacts are configured to generate a control signal for the MOS power switch module based on the on / off signal of the magnetic latching relay, and to provide the control signal of the MOS power switch module to the MOS power switch module. as well as The MOS power switch module is configured to turn on or off the current path between the satellite power bus and the load power supply module according to the control signal of the MOS power switch module.

2. The satellite power switching circuit as described in claim 1, characterized in that, Also includes: The gate drive and protection module is configured to be connected between the output terminal of the magnetic latching relay contact and the control terminal of the MOS power switch module; as well as The load power supply module is configured to provide operating current to the satellite load.

3. The satellite power switching circuit as described in claim 2, characterized in that, The gate driving and protection module includes: The gate current-limiting resistor is configured to provide a resistor that limits the gate current of the MOS power switch module; The gate pull-down resistor is configured to provide a resistor that limits the gate voltage of the MOS power switch module; The voltage regulator protection device is configured to provide a first protection shutdown signal for gate overvoltage faults in the MOS power switching module; and The transient suppression protection device is configured to provide a second protection shutdown signal for gate transient overcurrent faults of the MOS power switch module.

4. The satellite power switching circuit as described in claim 1, characterized in that, The MOS power switch module uses a combination of multiple metal-oxide-semiconductor field-effect transistors to form a power switching path, which includes multiple parallel conduction branches, each of which includes multiple series-connected shutdown branches.

5. The satellite power switching circuit as described in claim 1, characterized in that, The MOS power switch module includes a first parallel conduction branch and a second parallel conduction branch; The first parallel conducting branch and the second parallel conducting branch are connected in parallel between the satellite power bus and the load power supply module to divert the current path between the satellite power bus and the load power supply module. The first parallel conducting branch includes a first series shut-off branch and a second series shut-off branch connected in series, and the second parallel conducting branch includes a third series shut-off branch and a fourth series shut-off branch connected in series. Both the first and second parallel conducting branches are connected in series through two MOS transistors to form a double disconnect path. When a power-off operation is performed, the two MOS transistors are redundantly turned off to form redundant isolation.

6. The satellite power switching circuit as described in claim 1, characterized in that, The magnetic latching relay controller includes a first main unit control branch and a second standby unit control branch; The first host control branch provides the magnetic latching relay on / off signal to the first group of magnetic latching relay contacts; The second standby control branch provides the magnetic latching relay on / off signal to the second set of magnetic latching relay contacts; The first set of magnetic latching relay contacts provides the control signal for the first MOS power switch module; The second set of magnetic latching relay contacts provides control signals for the second MOS power switch module.

7. The satellite power switching circuit as described in claim 6, characterized in that, The first host control branch includes a first parallel control branch and a second parallel control branch; and the second standby control branch includes a third parallel control branch and a fourth parallel control branch; The first parallel control branch controls the first magnetic latching relay contact to be normally closed and the second magnetic latching relay contact to be normally open. The second parallel control branch controls the normally open contacts of the first magnetic latching relay and the normally closed contacts of the second magnetic latching relay; The third parallel control branch controls the normally open contacts of the third magnetic latching relay and the normally closed contacts of the fourth magnetic latching relay; The fourth parallel control branch controls the normally closed contacts of the fourth magnetic latching relay and the normally open contacts of the third magnetic latching relay.

8. A method for operating the satellite power switching circuit as described in claim 7, characterized in that, include: During the power-on process, the magnetic latching relay controller sends a load power-on command, and the magnetic latching relay contacts actuate. The magnetic latching relay contacts output a high-level control signal; The gates of two series-parallel MOS transistors obtain the turn-on voltage; Multiple MOSFETs are turned on simultaneously; the satellite power bus supplies power to the load power supply module through the MOSFET power switch module; During a power outage, the magnetic latching relay controller sends a power outage command, causing the magnetic latching relay contacts to reverse their action. The gate drive and protection module releases the MOS gate drive voltage; all MOS power switch modules are turned off; the output of the satellite power bus is isolated from the load power supply module.

9. The operation method of the satellite power switching circuit as described in claim 8, characterized in that, Also includes: When the satellite controller issues a load power-on command, the relay drive circuit receives the power-on control signal and outputs a positive pulse, causing the magnetic latching relay contacts to actuate. The magnetic latching relay contacts change from an open state to a closed state; The magnetic latching relay contacts output a control voltage, which is applied to the gate of the MOS power transistor via the gate drive resistor. The gate of the MOS power switch receives the turn-on voltage; During load power supply, the two parallel MOSFETs share the load current. When one of the MOS transistors experiences a fault such as increased on-resistance, performance degradation, or decreased current capability, the other parallel MOS transistor maintains the power supply path. When the satellite controller issues a load power-off command, the relay drive circuit outputs a reverse drive pulse, causing the magnetic latching relay contacts to reverse their action, the magnetic latching relay contacts to return to the open state, and the MOS gate drive voltage to be cut off. Release the MOS gate charge through the gate pull-down resistor; The gate-source voltage of the MOS power transistor decreases; All MOS devices are turned off, and the series MOS group is simultaneously cut off, achieving electrical isolation between the load and the satellite bus power supply. If a single MOS experiences a drain-source breakdown fault, a turn-off failure fault, or an abnormal increase in leakage current, another MOS provides isolation capability. Calculate the thermal shock power consumption of the magnetic latching relay contacts: ; When calculating the connection between the magnetic latching relay contacts and the main power circuit of the load, the operating current is 5A, and the relay on-resistance RCONTACT = 50mΩ. The calculated heat dissipation of the magnetic latching relay is 52 * 0.05 = 1.25W. Given that the relay's on-resistance RCONTACT = 50mΩ, RDS(ON) = 5 mΩ, and its operating current is 5A, then... Vdrop = I × Rc = 0.025V; The on-current of a single MOS is: ; The on-state current of the dual MOS transistors in parallel is: .

10. The operation method of the satellite power switching circuit as described in claim 8, characterized in that, Also includes: When the satellite controller issues a load power-on command or a load power-off command, if the first host control branch, the first set of magnetic latching relay contacts, or the first MOS power switch module fails, the second standby control branch will receive the power-on control signal or output a reverse drive pulse. The second set of magnetic latching relay contacts changes from the open state to the closed state; When the satellite controller issues a load power-on command, the first parallel control branch controls the second magnetic latching relay contact to be normally open, and the second parallel control branch controls the first magnetic latching relay contact to be normally open. When the satellite controller issues a load power-off command, the first parallel control branch controls the first magnetic latching relay contact to remain closed, and the second parallel control branch controls the second magnetic latching relay contact to remain closed.

Images