A master-backup redundant power supply switching circuit

Abstract

The application relates to a main backup redundant power supply switching circuit and belongs to the power supply field. The application comprises a surge current suppression circuit 1, an input filter circuit 2, a switch machine switching control circuit 3 and a DC / DC module circuit 4. The output end of the surge current suppression circuit 1 is connected with the input end of the input filter circuit 2, the output end of the input filter circuit 2 is connected with the input end of the DC / DC module circuit 4, and the output end of the switch machine switching control circuit 3 is connected with the input end of the surge current suppression circuit 1 and the input end of the DC / DC module circuit 4. The application adopts a super-small magnetic latching relay and a surge current suppression circuit, skillfully realizes the function of the on-orbit main backup redundant power supply switch machine switching control, further controls the DC / DC module enable end and the instruction interlocking diode through the parallel relay, and ensures that the power supply can be backed up and reliably shut down at any time. The application has the characteristics of small size and high reliability.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of power supply, and particularly relates to a main-backup redundant power supply switching circuit. BACKGROUND

[0002] The on-board integrated information processor is usually composed of a main-backup secondary power supply and an information processing unit, the main-backup secondary power supply is controlled by an external switch-on instruction, the main-backup is cold backup to each other, and the main-backup respectively supplies power to the main and backup information processing units. Therefore, it is particularly important to design a main-backup redundant power supply switching circuit. SUMMARY

[0003] (I) Technical problem to be solved

[0004] The technical problem to be solved by the application is how to provide a main-backup redundant power supply switching circuit to solve the problems of large volume and low reliability of a relay in series in a main power loop in a traditional power supply switching circuit scheme.

[0005] (II) Technical scheme

[0006] In order to solve the above technical problem, the application provides a main-backup redundant power supply switching circuit, which comprises a surge current suppression circuit (1), an input filter circuit (2), a switch-on switching control circuit (3) and a DC / DC module circuit (4); the output end of the surge current suppression circuit (1) is connected with the input end of the input filter circuit (2), the output end of the input filter circuit (2) is connected with the input end of the DC / DC module circuit (4), and the output end of the switch-on switching control circuit (3) is connected with the input end of the surge current suppression circuit (1) and the input end of the DC / DC module circuit (4).

[0007] The input of the surge current suppression circuit (1) is Vin, the output end is connected with the input end of the input filter circuit (2), the output end of the input filter circuit (2) is connected with the input end of the DC / DC module circuit (4), the output of the DC / DC module circuit (4) is Vout, the input end of the switch-on switching control circuit (3) is a main-on instruction Zon, a main-off instruction Zoff, a backup-on instruction Bon, a backup-off instruction Boff and an instruction bus ZLdc, the output end Zen is connected with the input end of the surge current suppression circuit, and the other output end Zdcen is connected with the input end of the DC / DC module circuit.

[0008] (III) Beneficial effects

[0009] The application provides a main backup redundant power supply switching circuit, adopts a super-small magnetic latching relay and a surge current suppression circuit, and ingeniously realizes the function of on-off switching control of the satellite-borne main backup redundant power supply, and further ensures that the power supply can be backed up and reliably shut down at any time through parallel relay control of the DC / DC module enable end and the instruction interlocking diode. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 The application discloses a satellite-borne main backup power supply redundant power supply switching circuit.

[0011] Figure 2 The application discloses a satellite-borne main backup power supply redundant power supply switching circuit.

[0012] Figure 3 The application discloses a satellite-borne main backup power supply redundant power supply switching circuit.

[0013] Figure 4 The application discloses a satellite-borne main backup power supply redundant power supply switching circuit.

[0014] Figure 5 The application discloses a satellite-borne main backup power supply redundant power supply switching circuit. DETAILED DESCRIPTION

[0015] In order to make the purpose, content and advantages of the application clearer, the specific embodiments of the application are further described in detail below with reference to the drawings and examples.

[0016] The application discloses a satellite-borne main backup power supply redundant power supply switching circuit, which comprises a surge current suppression circuit (1), an input filter circuit (2), an on-off switching control circuit (3) and a DC / DC module circuit (4). The output end of the surge current suppression circuit (1) is connected with the input end of the input filter circuit (2), the output end of the input filter circuit (2) is connected with the input end of the DC / DC module circuit (4), and the output end of the on-off switching control circuit (3) is connected with the input end of the surge current suppression circuit (1) and the input end of the DC / DC module circuit (4).

[0017] The application aims to provide a satellite-borne main backup power supply redundant power supply switching circuit and method, and solve the problem of large volume and low reliability of a relay in a traditional power supply switching circuit scheme.

[0018] A kind of on-orbit main backup power supply redundant power supply switching circuit, comprising: surge current suppression circuit, switch machine switching control circuit, input filter circuit, DC / DC module circuit.

[0019] The input of surge current suppression circuit is Vin, and the output end is connected with the input end of input filter circuit, the output end of input filter circuit is connected with the input end of DC / DC module circuit, the output of DC / DC module circuit is Vout, the input end of switch machine switching control circuit is main open command Zon, main off command Zoff, backup start command Bon, backup off command Boff and command bus ZLdc, the output end Zen is connected with the input end of surge current suppression circuit, another output end Zdcen is connected with the input end of DC / DC module circuit.

[0020] Wherein, surge current suppression circuit includes: fuse F1, fuse F2, protection resistance R1, voltage dividing resistance R2, voltage dividing resistance R3, current limiting resistance R4, current limiting resistance R5, current limiting resistance R6, differential mode capacitor C1, differential mode capacitor C2, voltage stabilizing diode D1, voltage stabilizing diode D2, power field effect transistor S1, power field effect transistor S2.Switch machine switching control circuit includes: magnetic latching relay JB1, magnetic latching relay JB2, diode D3, diode D4, protection diode D5, protection diode D6, current limiting resistance R7, current limiting resistance R8.Input filter circuit includes: common mode inductor L1, differential mode inductor L2, differential mode capacitor C3, differential mode capacitor C4, common mode capacitor C5, common mode capacitor C6.DC / DC module circuit includes: DC / DC module N1, current limiting resistance R9, filter capacitor C7.

[0021] In the surge current suppression circuit, one end of fuses F1 and F2 is connected to the positive input terminal Vin+, and the other end of fuse F1 is connected to the positive output terminal Va+. The other end of fuse F2 is connected to one end of the protective resistor R1, and the other end of the protective resistor R1 is connected to the positive output terminal Va+. One end of the voltage divider resistor R2 is connected to the positive output terminal Va+, and the other end of the voltage divider resistor R2 is connected to one end of the differential-mode capacitor C1, one end of the voltage divider resistor R3, one end of the current-limiting resistor R4, the cathode of the Zener diode D1, one end of the current-limiting resistor R5, and one end of the current-limiting resistor R6. The anode of the Zener diode D1 is connected to the cathode of the Zener diode D2. One end of the differential-mode capacitor C2 is connected to the differential-mode capacitor C1. At the other end, the other end of the voltage divider resistor R3, the other end of the differential mode capacitor C2, and the anode of the Zener diode D2 are connected to the negative input terminal Vin-. The other end of the current limiting resistor R4 is connected to one end of contacts K1 and K2. The other ends of K1 and K2 are connected to the negative input terminal Vin-. Contacts K1 and K2 are controlled by the enable signal Zen. The other end of the current limiting resistor R5 is connected to the gate of the power MOSFET S1. The other end of the current limiting resistor R6 is connected to the gate of the power MOSFET S2. The source of the power MOSFET S1 and the source of the power MOSFET S2 are connected to the negative input terminal Vin-. The drain of the power MOSFET S1 and the drain of the power MOSFET S2 are connected to the negative output terminal Va-.

[0022] In the power-on / off switching control circuit, the contacts K1-1 and K2-1 of the magnetic latching relay JB1 are connected to the enable signal Zen, and the other contacts K1-2 and K2-2 are connected to the negative input terminal Vin-. The positive terminal of the coil J1 of the magnetic latching relay JB1 is connected to one end of the current-limiting resistor R7, and the negative terminal of the coil J1 is connected to the main power-on command Zon. The positive terminal of the coil J2 of the magnetic latching relay JB1 is connected to one end of the current-limiting resistor R8, and the negative terminal of the coil J2 is connected to the main power-off command Zoff. The other ends of the current-limiting resistors R7 and R8 are connected to the command bus ZLdc. The anode of diode D3 is connected to the backup power-off command Boff, and the cathode of diode D3 is connected to the negative terminal of the coil J1 of the magnetic latching relay JB1. The anode of diode D4 is connected to the main power-off command Zoff, and the cathode of diode D4 is connected to the negative terminal of the coil J2 of the magnetic latching relay JB1. The contacts K3-1 and K4-1 of the magnetic latching relay JB2 are connected to the enable signal Zdcen, and the other contacts K3-2 and K4-2 are connected to the negative input terminal Vb-. The positive terminal of the coil J3 of the magnetic latching relay JB2 is connected to the positive terminal of the coil J1 of the magnetic latching relay JB1, and the anode of the protection diode D6 is connected. The negative terminal of the coil J3 of the magnetic latching relay JB2 is connected to the negative terminal of the coil J1 of the magnetic latching relay JB1, and the cathode of the protection diode D6 is connected. The positive terminal of the coil J4 of the magnetic latching relay JB2 is connected to the positive terminal of the coil J2 of the magnetic latching relay JB1, and the anode of the protection diode D5 is connected. The negative terminal of the coil J4 of the magnetic latching relay JB2 is connected to the negative terminal of the coil J2 of the magnetic latching relay JB1, and the cathode of the protection diode D5 is connected.

[0023] In the input filter circuit, the positive input terminal of common-mode inductor L1 is connected to the positive input terminal Va+. One end of differential-mode capacitor C3 is connected to the positive input terminal Va+. The other end of differential-mode capacitor C3 and the negative input terminal of common-mode inductor L1 are both connected to the negative input terminal Va-. The positive output terminal of common-mode inductor L1 is connected to one end of differential-mode inductor L2 and one end of differential-mode capacitor C4. The other end of differential-mode capacitor C4 is connected to the negative output terminal of common-mode inductor L1. The other end of differential-mode inductor L2 is connected to one end of common-mode capacitor C5 and the positive output terminal Vb+. The other end of common-mode capacitor C5 is connected to chassis ground and one end of common-mode capacitor C6. The other end of common-mode capacitor C6 and the negative output terminal of common-mode inductor L1 are both connected to the negative output terminal Vb-.

[0024] In the DC / DC module circuit, the high-side input Vb+ is connected to the positive input terminal +IN of DC / DC module N1, and the low-side input Vb- is connected to the negative input terminal -IN of DC / DC module N1. One end of the current-limiting resistor R9 is connected to the disable terminal INH of DC / DC module N1, and the other end of the current-limiting resistor R9 is connected to the contacts K3 and K4 of magnetic latching relay JB1. One end of the filter capacitor C7 is connected to the positive output terminal +OUT and the high-side output Vout+ of DC / DC module N1, and the other end of the filter capacitor C7 is connected to the negative output terminal -OUT and the negative output terminal Vout- of DC / DC module N1.

[0025] In a redundant power supply switching circuit and method for a spaceborne main backup power supply, the input Vin enters the surge suppression circuit to suppress the input surge current. Simultaneously, the ingenious combination of contacts K1 and K2 of the magnetic latching relay JB1 with power MOSFETs S1 and S2 enables power-on / off switching control using a small relay. A double fuse F1 and F2 and a protection resistor R1 are designed at the power input. When an overcurrent fault occurs in the secondary power supply or downstream load, the fuses open, cutting off the connection to the primary bus and protecting the primary bus. The double fuses F1 and F2 are used in parallel to prevent the other fuse from operating normally after one fuse blows. Voltage divider resistors R2 and R3, and differential mode capacitors C1 and C2 form a charging and discharging circuit. The two pairs of contacts K1 and K2 of the magnetic latching relay JB1 are initially closed. The current-limiting resistor R4 limits the current and protects contacts K1 and K2. Current-limiting resistors R5 and R6 are the gate protection resistors for power MOSFETs S1 and S2, respectively. Zener diodes D1 and D2 stabilize the gate-source voltage of power MOSFETs S1 and S2. When the input voltage Vin is applied, contacts K1 and K2 are closed, resulting in low gate-source voltages for power MOSFETs S1 and S2, which are in the off state. When the magnetic latching relay JB1 responds to an external power-on command, contacts K1 and K2 open, and Vin charges the differential-mode capacitors C1 and C2 through the voltage divider resistor R2. Power MOSFETs S1 and S2 slowly turn on until fully conducting, suppressing input inrush current. The output voltage Va then reaches the subsequent input filter circuit.

[0026] The input filter circuit filters out external electromagnetic interference introduced from the primary power bus and suppresses electromagnetic interference emitted by the high-frequency switching circuit to prevent it from affecting the normal operation of other electronic devices in the same electromagnetic environment. Va enters the input filter circuit for common-mode and differential-mode signal filtering, and then outputs Vb, which is sent to the DC / DC module circuit.

[0027] In the DC / DC module circuit, the disable terminal INH of DC / DC module N1 is controlled by magnetic latching relay JB2. When magnetic latching relay JB2 responds to an external power-on command, the two pairs of contacts K3 and K4 open, and the module starts working. The input voltage Vb is isolated and transformed by N1 to output a stable DC voltage Vout. When magnetic latching relay JB2 responds to an external power-off command, the two pairs of contacts K3 and K4 close, and the module stops working. This prevents the downstream DC / DC module circuit from switching in case of short-circuit failure of power MOSFETs S1 and S2 in the surge suppression circuit, ensuring reliable shutdown.

[0028] In the power-on / off switching circuit, the two sets of coils of magnetic latching relay JB1 are connected in parallel with the two sets of coils of JB2. Initially, contacts K1 and K2 of magnetic latching relay JB1 are closed, and contacts K3 and K4 of magnetic latching relay JB2 are closed, with both main and backup power supplies off. When responding to an external low-level active power-on command Zon, the command bus voltage ZLdc passes through coil J1 of magnetic latching relay JB1 and coil J3 of magnetic latching relay JB2, causing contacts K1 and K2 of JB1 to operate, and contacts K3 and K4 of JB2 to operate. The operation of K1 and K2 disconnects Zen from Vin (-), allowing Vin to slowly charge C1 and C2 through R2, slowly turning on the MOSFET in the main surge suppression circuit. The operation of K3 and K4 disconnects Zen from Vb-, changing the enable terminal of the main DC / DC module from disabled to enabled. Conversely, when responding to the external low-level active shutdown command Zoff, relay contacts K1, K2, K3, and K4 return to their initial state, and the main power supply is turned off. Protection diodes D5 and D6 eliminate the coil back EMF. Diodes D3 and D4 provide interlocking for the main and backup power-on / off commands; that is, when responding to the main power-on command Zon, the backup circuit's Boff command is forcibly pulled low, ensuring backup shutdown; when responding to the backup power-on command Bon, the main circuit's Zoff command is forcibly pulled low, ensuring main shutdown. This prevents simultaneous power-on of the main and backup circuits, achieving cold backup functionality.

[0029] This invention cleverly uses an ultra-miniature magnetic latching relay and surge current suppression circuit to realize the function of switching control of the on-board main backup redundant power supply. Furthermore, it uses parallel relays to control the enable terminal of the DC / DC module and the command interlock diode to ensure that the power supply can be backed up and reliably shut down at any time. It has the characteristics of small size and high reliability.

[0030] Example 1:

[0031] A satellite-borne primary / backup power supply redundancy switching circuit includes: a surge current suppression circuit, a power-on / off switching control circuit, an input filtering circuit, and a DC / DC module circuit. The surge current suppression circuit includes: fuses F1 and F2, a protective resistor R1, voltage divider resistors R2 and R3, current-limiting resistors R4, R5, and R6, differential-mode capacitors C1 and C2, Zener diodes D1 and D2, and power MOSFETs S1 and S2. The power-on / off switching control circuit includes: magnetic latching relays JB1 and JB2, diodes D3 and D4, a protective diode D5 and D6, and current-limiting resistors R7 and R8. The input filtering circuit includes: a common-mode inductor L1, a differential-mode inductor L2, differential-mode capacitors C3 and C4, and common-mode capacitors C5 and C6. The DC / DC module circuit includes: DC / DC module N1, current limiting resistor R9, and filter capacitor C7.

[0032] The surge current suppression circuit has Vin as its input and its output connected to the input of the input filter circuit. The output of the input filter circuit is connected to the input of the DC / DC module circuit, and the output of the DC / DC module circuit is Vout. The power-on / off switching control circuit has the following inputs: primary power-on command Zon, primary power-off command Zoff, backup power-on command Bon, backup power-off command Boff, and command bus ZLdc. Its output Zen is connected to the input of the surge current suppression circuit, and its other output Zdcen is connected to the input of the DC / DC module circuit.

[0033] In the surge current suppression circuit, one end of fuses F1 and F2 is connected to the positive input terminal Vin+, and the other end of fuse F1 is connected to the positive output terminal Va+. The other end of fuse F2 is connected to one end of the protective resistor R1, and the other end of the protective resistor R1 is connected to the positive output terminal Va+. One end of the voltage divider resistor R2 is connected to the positive output terminal Va+, and the other end of the voltage divider resistor R2 is connected to one end of the differential-mode capacitor C1, one end of the voltage divider resistor R3, one end of the current-limiting resistor R4, the cathode of the Zener diode D1, one end of the current-limiting resistor R5, and one end of the current-limiting resistor R6. The anode of the Zener diode D1 is connected to the cathode of the Zener diode D2. One end of the differential-mode capacitor C2 is connected to the differential-mode capacitor C1. At the other end, the other end of the voltage divider resistor R3, the other end of the differential mode capacitor C2, and the anode of the Zener diode D2 are connected to the negative input terminal Vin-. The other end of the current limiting resistor R4 is connected to one end of contacts K1 and K2. The other ends of K1 and K2 are connected to the negative input terminal Vin-. Contacts K1 and K2 are controlled by the enable signal Zen. The other end of the current limiting resistor R5 is connected to the gate of the power MOSFET S1. The other end of the current limiting resistor R6 is connected to the gate of the power MOSFET S2. The source of the power MOSFET S1 and the source of the power MOSFET S2 are connected to the negative input terminal Vin-. The drain of the power MOSFET S1 and the drain of the power MOSFET S2 are connected to the negative output terminal Va-.

[0034] In the power-on / off switching control circuit, the contacts K1-1 and K2-1 of the magnetic latching relay JB1 are connected to the enable signal Zen, and the other contacts K1-2 and K2-2 are connected to the negative input terminal Vin-. The positive terminal of the coil J1 of the magnetic latching relay JB1 is connected to one end of the current-limiting resistor R7, and the negative terminal of the coil J1 is connected to the main power-on command Zon. The positive terminal of the coil J2 of the magnetic latching relay JB1 is connected to one end of the current-limiting resistor R8, and the negative terminal of the coil J2 is connected to the main power-off command Zoff. The other ends of the current-limiting resistors R7 and R8 are connected to the command bus ZLdc. The anode of diode D3 is connected to the backup power-off command Boff, and the cathode of diode D3 is connected to the negative terminal of the coil J1 of the magnetic latching relay JB1. The anode of diode D4 is connected to the main power-off command Zoff, and the cathode of diode D4 is connected to the negative terminal of the coil J2 of the magnetic latching relay JB1. The contacts K3-1 and K4-1 of the magnetic latching relay JB2 are connected to the enable signal Zdcen, and the other contacts K3-2 and K4-2 are connected to the negative input terminal Vb-. The positive terminal of the coil J3 of the magnetic latching relay JB2 is connected to the positive terminal of the coil J1 of the magnetic latching relay JB1, and the anode of the protection diode D6 is connected. The negative terminal of the coil J3 of the magnetic latching relay JB2 is connected to the negative terminal of the coil J1 of the magnetic latching relay JB1, and the cathode of the protection diode D6 is connected. The positive terminal of the coil J4 of the magnetic latching relay JB2 is connected to the positive terminal of the coil J2 of the magnetic latching relay JB1, and the anode of the protection diode D5 is connected. The negative terminal of the coil J4 of the magnetic latching relay JB2 is connected to the negative terminal of the coil J2 of the magnetic latching relay JB1, and the cathode of the protection diode D5 is connected.

[0035] In the input filter circuit, the positive input terminal of common-mode inductor L1 is connected to the positive input terminal Va+. One end of differential-mode capacitor C3 is connected to the positive input terminal Va+. The other end of differential-mode capacitor C3 and the negative input terminal of common-mode inductor L1 are both connected to the negative input terminal Va-. The positive output terminal of common-mode inductor L1 is connected to one end of differential-mode inductor L2 and one end of differential-mode capacitor C4. The other end of differential-mode capacitor C4 is connected to the negative output terminal of common-mode inductor L1. The other end of differential-mode inductor L2 is connected to one end of common-mode capacitor C5 and the positive output terminal Vb+. The other end of common-mode capacitor C5 is connected to chassis ground and one end of common-mode capacitor C6. The other end of common-mode capacitor C6 and the negative output terminal of common-mode inductor L1 are both connected to the negative output terminal Vb-.

[0036] In the DC / DC module circuit, the high-side input Vb+ is connected to the positive input terminal +IN of DC / DC module N1, and the low-side input Vb- is connected to the negative input terminal -IN of DC / DC module N1. One end of the current-limiting resistor R9 is connected to the disable terminal INH of DC / DC module N1, and the other end of the current-limiting resistor R9 is connected to the contacts K3 and K4 of magnetic latching relay JB1. One end of the filter capacitor C7 is connected to the positive output terminal +OUT and the high-side output Vout+ of DC / DC module N1, and the other end of the filter capacitor C7 is connected to the negative output terminal -OUT and the negative output terminal Vout- of DC / DC module N1.

[0037] In a redundant power supply switching circuit and method for a spaceborne main backup power supply, the input Vin enters the surge suppression circuit to suppress the input surge current. Simultaneously, the ingenious combination of contacts K1 and K2 of the magnetic latching relay JB1 with power MOSFETs S1 and S2 enables power-on / off switching control using a small relay. A double fuse F1 and F2 and a protection resistor R1 are designed at the power input. When an overcurrent fault occurs in the secondary power supply or downstream load, the fuses open, cutting off the connection to the primary bus and protecting the primary bus. The double fuses F1 and F2 are used in parallel to prevent the other fuse from operating normally after one fuse blows. Voltage divider resistors R2 and R3, and differential mode capacitors C1 and C2 form a charging and discharging circuit. The two pairs of contacts K1 and K2 of the magnetic latching relay JB1 are initially closed. The current-limiting resistor R4 limits the current and protects contacts K1 and K2. Current-limiting resistors R5 and R6 are the gate protection resistors for power MOSFETs S1 and S2, respectively. Zener diodes D1 and D2 stabilize the gate-source voltage of power MOSFETs S1 and S2. When the input voltage Vin is applied, contacts K1 and K2 are closed, resulting in low gate-source voltages for power MOSFETs S1 and S2, which are in the off state. When the magnetic latching relay JB1 responds to an external power-on command, contacts K1 and K2 open, and Vin charges the differential-mode capacitors C1 and C2 through the voltage divider resistor R2. Power MOSFETs S1 and S2 slowly turn on until fully conducting, suppressing input inrush current. The output voltage Va then reaches the subsequent input filter circuit.

[0038] The input filter circuit filters out external electromagnetic interference introduced from the primary power bus and suppresses electromagnetic interference emitted by the high-frequency switching circuit to prevent it from affecting the normal operation of other electronic devices in the same electromagnetic environment. Va enters the input filter circuit for common-mode and differential-mode signal filtering, and then outputs Vb, which is sent to the DC / DC module circuit.

[0039] In the DC / DC module circuit, the disable terminal INH of DC / DC module N1 is controlled by magnetic latching relay JB2. When magnetic latching relay JB2 responds to an external power-on command, the two pairs of contacts K3 and K4 open, and the module starts working. The input voltage Vb is isolated and transformed by N1 to output a stable DC voltage Vout. When magnetic latching relay JB2 responds to an external power-off command, the two pairs of contacts K3 and K4 close, and the module stops working. This prevents the downstream DC / DC module circuit from switching in case of short-circuit failure of power MOSFETs S1 and S2 in the surge suppression circuit, ensuring reliable shutdown.

[0040] In the power-on / off switching circuit, the two sets of coils of magnetic latching relay JB1 are connected in parallel with the two sets of coils of JB2. Initially, contacts K1 and K2 of magnetic latching relay JB1 are closed, and contacts K3 and K4 of magnetic latching relay JB2 are closed, with both main and backup power supplies off. When responding to an external low-level active power-on command Zon, the command bus voltage ZLdc passes through coil J1 of magnetic latching relay JB1 and coil J3 of magnetic latching relay JB2, causing contacts K1 and K2 of JB1 to operate, and contacts K3 and K4 of JB2 to operate. The operation of K1 and K2 disconnects Zen from Vin (-), allowing Vin to slowly charge C1 and C2 through R2, slowly turning on the MOSFET in the main surge suppression circuit. The operation of K3 and K4 disconnects Zen from Vb (-), changing the enable terminal of the main DC / DC module from disabled to enabled. Conversely, when responding to the external low-level active shutdown command Zoff, relay contacts K1, K2, K3, and K4 return to their initial state, and the main power supply is turned off. Protection diodes D5 and D6 eliminate the coil back EMF. Diodes D3 and D4 provide interlocking for the main and backup power-on / off commands; that is, when responding to the main power-on command Zon, the backup circuit's Boff command is forcibly pulled low, ensuring backup shutdown; when responding to the backup power-on command Bon, the main circuit's Zoff command is forcibly pulled low, ensuring main shutdown. This prevents simultaneous power-on of the main and backup circuits, achieving cold backup functionality.

[0041] This invention employs an ultra-miniature magnetic latching relay and surge current suppression circuit to ingeniously achieve the function of switching control for redundant power supply for spaceborne primary backup. Furthermore, it uses parallel relays to control the enable terminal of the DC / DC module and command interlock diodes to ensure that the power supply is always capable of backup and reliable shutdown. This invention provides a redundant power supply switching circuit and method for spaceborne primary backup power, solving the problems of large size and low reliability associated with relays connected in series in the main power circuit in traditional power supply switching circuits. It features small size and high reliability.

[0042] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A primary / backup redundant power supply switching circuit, characterized in that, The circuit includes a surge current suppression circuit (1), an input filter circuit (2), a power on / off switching control circuit (3), and a DC / DC module circuit (4); the output terminal of the surge current suppression circuit (1) is connected to the input terminal of the input filter circuit (2), the output terminal of the input filter circuit (2) is connected to the input terminal of the DC / DC module circuit (4), and the output terminal of the power on / off switching control circuit (3) is connected to the input terminal of the surge current suppression circuit (1) and the input terminal of the DC / DC module circuit (4). The input of the surge current suppression circuit (1) is Vin, and the output is connected to the input of the input filter circuit (2). The output of the input filter circuit (2) is connected to the input of the DC / DC module circuit (4). The output of the DC / DC module circuit (4) is Vout. The input of the power-on switching control circuit (3) is the main power-on instruction Zon, the main power-off instruction Zoff, the backup power-on instruction Bon, the backup power-off instruction Boff and the instruction bus ZLdc. The output Zen is connected to the input of the surge current suppression circuit, and the other output Zdcen is connected to the input of the DC / DC module circuit. in, The surge current suppression circuit (1) includes: fuse F1, fuse F2, protection resistor R1, voltage divider resistor R2, voltage divider resistor R3, current limiting resistor R4, current limiting resistor R5, current limiting resistor R6, differential mode capacitor C1, differential mode capacitor C2, Zener diode D1, Zener diode D2, power MOSFET S1, power MOSFET S2; the power on / off switching control circuit includes: magnetic latching relay JB1, magnetic latching relay JB2, diode D3, diode D4, protection diode D5, protection diode D6, current limiting resistor R7, current limiting resistor R8; the input filter circuit includes: common mode inductor L1, differential mode inductor L2, differential mode capacitor C3, differential mode capacitor C4, common mode capacitor C5, common mode capacitor C6; the DC / DC module circuit includes: DC / DC module N1, current limiting resistor R9 and filter capacitor C7; In the surge current suppression circuit, one end of fuses F1 and F2 is connected to the positive input terminal Vin+, and the other end of fuse F1 is connected to the positive output terminal Va+. The other end of fuse F2 is connected to one end of the protective resistor R1, and the other end of the protective resistor R1 is connected to the positive output terminal Va+. One end of the voltage divider resistor R2 is connected to the positive output terminal Va+, and the other end of the voltage divider resistor R2 is connected to one end of the differential-mode capacitor C1, one end of the voltage divider resistor R3, one end of the current-limiting resistor R4, the cathode of the Zener diode D1, one end of the current-limiting resistor R5, and one end of the current-limiting resistor R6. The anode of the Zener diode D1 is connected to the cathode of the Zener diode D2. One end of the differential-mode capacitor C2 is connected to the differential-mode capacitor C1. At the other end, the other end of the voltage divider resistor R3, the other end of the differential mode capacitor C2, and the anode of the Zener diode D2 are connected to the negative input terminal Vin-. The other end of the current limiting resistor R4 is connected to one end of contacts K1 and K2. The other ends of K1 and K2 are connected to the negative input terminal Vin-. Contacts K1 and K2 are controlled by the enable signal Zen. The other end of the current limiting resistor R5 is connected to the gate of the power MOSFET S1. The other end of the current limiting resistor R6 is connected to the gate of the power MOSFET S2. The source of the power MOSFET S1 and the source of the power MOSFET S2 are connected to the negative input terminal Vin-. The drain of the power MOSFET S1 and the drain of the power MOSFET S2 are connected to the negative output terminal Va-.

2. The primary / backup redundant power supply switching circuit as described in claim 1, characterized in that, In the power-on / off switching control circuit, one end of contacts K1 and K2 of the magnetic latching relay JB1, K1-1 and K2-1, is connected to the enable signal Zen, and the other end, K1-2 and K2-2, is connected to the negative input terminal Vin-. The positive terminal of the coil J1 of the magnetic latching relay JB1 is connected to one end of the current-limiting resistor R7, and the negative terminal of the coil J1 is connected to the main power-on command Zon. The positive terminal of the coil J2 of the magnetic latching relay JB1 is connected to one end of the current-limiting resistor R8, and the negative terminal of the coil J2 is connected to the main power-off command Zoff. The other ends of the current-limiting resistors R7 and R8 are connected to the command bus ZLdc. The anode of diode D3 is connected to the backup power-off command Boff, the cathode of diode D3 is connected to the negative terminal of the coil J1 of the magnetic latching relay JB1, and the anode of diode D4 is connected to the main power-off command Zoff. The cathode of diode D4 is connected to the negative terminal of coil J2 of magnetic latching relay JB1; one end of contacts K3 and K4 of magnetic latching relay JB2, K3-1 and K4-1, are connected to the enable signal Zdcen, and the other end of contacts K3-2 and K4-2 are connected to the negative input terminal Vb-; the positive terminal of coil J3 of magnetic latching relay JB2 is connected to the positive terminal of coil J1 of magnetic latching relay JB1, and the anode of protection diode D6 is connected; the negative terminal of coil J3 of magnetic latching relay JB2 is connected to the negative terminal of coil J1 of magnetic latching relay JB1, and the cathode of protection diode D6 is connected; the positive terminal of coil J4 of magnetic latching relay JB2 is connected to the positive terminal of coil J2 of magnetic latching relay JB1, and the anode of protection diode D5 is connected; the negative terminal of coil J4 of magnetic latching relay JB2 is connected to the negative terminal of coil J2 of magnetic latching relay JB1, and the cathode of protection diode D5 is connected.

3. The primary / backup redundant power supply switching circuit as described in claim 2, characterized in that, In the input filter circuit, the positive input terminal of common-mode inductor L1 is connected to the positive input terminal Va+. One end of differential-mode capacitor C3 is connected to the positive input terminal Va+. The other end of differential-mode capacitor C3 and the negative input terminal of common-mode inductor L1 are both connected to the negative input terminal Va-. The positive output terminal of common-mode inductor L1 is connected to one end of differential-mode inductor L2 and one end of differential-mode capacitor C4. The other end of differential-mode capacitor C4 is connected to the negative output terminal of common-mode inductor L1. The other end of differential-mode inductor L2 is connected to one end of common-mode capacitor C5 and the positive output terminal Vb+. The other end of common-mode capacitor C5 is connected to chassis ground and one end of common-mode capacitor C6. The other end of common-mode capacitor C6 and the negative output terminal of common-mode inductor L1 are both connected to the negative output terminal Vb-.

4. The primary / backup redundant power supply switching circuit as described in claim 3, characterized in that, In the DC / DC module circuit, the high-side input Vb+ is connected to the positive input terminal +IN of DC / DC module N1, and the low-side input Vb- is connected to the negative input terminal -IN of DC / DC module N1. One end of the current-limiting resistor R9 is connected to the disable terminal INH of DC / DC module N1, and the other end of the current-limiting resistor R9 is connected to the contacts K3 and K4 of magnetic latching relay JB1. One end of the filter capacitor C7 is connected to the positive output terminal +OUT and the high-side output Vout+ of DC / DC module N1, and the other end of the filter capacitor C7 is connected to the negative output terminal -OUT and the negative output terminal Vout- of DC / DC module N1.

5. The primary / backup redundant power supply switching circuit as described in claim 4, characterized in that, The input Vin enters the surge suppression circuit. At the power inlet, dual fuses F1 and F2 and a protective resistor R1 are designed. When an overcurrent fault occurs in the secondary power supply or downstream load, the fuses open, cutting off the connection to the primary bus and protecting it. The dual fuses F1 and F2 are used in parallel to prevent the other fuse from operating normally if one fuse blows accidentally. Voltage divider resistors R2 and R3, and differential mode capacitors C1 and C2 form the charging and discharging circuit. The two pairs of contacts K1 and K2 of the magnetic latching relay JB1 are initially closed. The current-limiting resistor R4 limits the current and protects contacts K1 and K2. Current-limiting resistors R5 and R6 are the gate protection resistors for power MOSFETs S1 and S2, respectively. Zener diodes D1 and D2 stabilize the gate-source voltage of power MOSFETs S1 and S2. When the input voltage Vin is applied, contacts K1 and K2 close, the gate-source voltage of power MOSFETs S1 and S2 is low, and S1 and S2 are in the off state. When the magnetic latching relay JB1 responds to the external power-on command, contacts K1 and K2 open, Vin charges the differential mode capacitors C1 and C2 through the voltage divider resistor R2, and the power MOSFETs S1 and S2 slowly turn on until they are fully turned on, which suppresses the input surge current. The output voltage Va is sent to the subsequent input filter circuit.

6. The primary / backup redundant power supply switching circuit as described in claim 4, characterized in that, The input filter circuit filters out external electromagnetic interference introduced into the primary power bus and suppresses electromagnetic interference emitted by the high-frequency switching circuit. Va enters the input filter circuit for common-mode and differential-mode signal filtering and outputs Vb, which is then sent to the DC / DC module circuit.

7. The primary / backup redundant power supply switching circuit as described in claim 4, characterized in that, In the DC / DC module circuit, the N1 disable terminal INH of the DC / DC module is controlled by the magnetic latching relay JB2. When the magnetic latching relay JB2 responds to an external power-on command, the two pairs of contacts K3 and K4 open, and the module starts working. The input voltage Vb is isolated and transformed by N1 to output a stable DC voltage Vout. When the magnetic latching relay JB2 responds to an external power-off command, the two pairs of contacts K3 and K4 close, and the module is disabled. This prevents the power MOSFETs S1 and S2 in the surge suppression circuit from short-circuiting and failing, thus switching the subsequent DC / DC module circuit to ensure reliable shutdown.

8. The primary / backup redundant power supply switching circuit as described in any one of claims 4-7, characterized in that, In the power-on / off switching circuit, the two sets of coils of magnetic latching relay JB1 are connected in parallel with the two sets of coils of JB2, respectively. Initially, contacts K1 and K2 of magnetic latching relay JB1 are closed, and contacts K3 and K4 of magnetic latching relay JB2 are closed, with both main and backup power supplies off. When a low-level active power-on command Zon is received, the command bus voltage ZLdc passes through coil J1 of magnetic latching relay JB1 and coil J3 of magnetic latching relay JB2, causing contacts K1 and K2 of JB1 to actuate, and contacts K3 and K4 of JB2 to actuate.

4. Operation: When contacts K1 and K2 operate, Zen is disconnected from Vin-. Vin slowly charges C1 and C2 through R2, and the MOSFET in the main surge suppression circuit slowly turns on. When contacts K3 and K4 operate, Zdcen is disconnected from Vb-, and the enable terminal of the main DC / DC module changes from disabled to enabled. Conversely, when responding to the external low-level active shutdown command Zoff, relay contacts K1, K2, K3, and K4 return to their initial state, and the main power supply is turned off. Protection diodes D5 and D6 serve to eliminate the back EMF of the coil. Diodes D3 and D4 serve as interlocking mechanisms for the main and backup power-on / off commands. That is, when the main power-on command Zon is received, the backup circuit's Boff command is forcibly pulled low to ensure the backup is powered off. When responding to the backup power-on command Bon, the Zoff command of the primary circuit is forcibly pulled low to ensure that the primary circuit is powered off. This prevents the primary and backup circuits from being powered on simultaneously at any time, thus achieving the function of cold backup.

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