A power supply redundancy protection circuit

Abstract

The application provides a power supply redundancy protection circuit, which comprises a power supply state detection unit, a power supply switch control unit, a power supply redundancy protection unit, a first power supply unit and a second power supply unit; the input end of the power supply state detection unit is connected with a first power supply signal and a second power supply signal, and is used for outputting a power supply state detection signal based on the first power supply signal and the second power supply signal; the power supply switch control unit is connected with the power supply state detection unit, and is used for outputting a power supply switch control signal; the power supply redundancy protection unit is connected with the power supply switch control unit, and is used for selecting the first power supply unit or the second power supply unit for power supply. The application realizes the power supply redundancy protection function by using fewer components; supports power supply hot plug, realizes high availability and continuity of the power supply system, supports power supply overvoltage protection and under-voltage protection, guarantees the stability and reliability of system operation, and has simple implementation scheme and low cost.

Description

Technical Field

[0001] This invention relates to the field of power supply design technology, and in particular to a power supply redundancy protection circuit. Background Technology

[0002] In a redundant hot standby control system, the entire PLC control system includes two identical PLC main units, power supplies, and redundant processing modules. The two controller subunits operate in parallel using the same user program; one controller is the primary controller, and the other is the backup controller. When the primary controller fails, the system automatically switches to the backup controller to ensure stable, reliable, and continuous operation of the PLC control system. Besides the redundant dual-machine function of the PLC main units, the power supply also requires redundant protection. This redundancy ensures long-term stable operation and highly reliable automated control within the PLC control system. Existing power supply redundancy protection schemes utilize a detection module to detect the status information of the voltage input terminal and output this information to a monitoring module. The monitoring module controls the switches in the switching module to close or open based on the input status information. The switching module controls the power distribution module's voltage allocation and the power module's connection or disconnection via the opening and closing of the switches, thus achieving power redundancy. However, existing power supply redundancy protection schemes are complex to implement, difficult to execute, and costly.

[0003] Hot-swapping, or hot-plugging, refers to inserting or removing modules or boards into or from a system without shutting down the system power supply, thus improving system reliability, rapid maintainability, redundancy, and timely disaster recovery capabilities. For high-power modular power systems, hot-swapping technology allows for the replacement of faulty power modules while maintaining the overall system voltage, ensuring the normal operation of other power modules within the modular power system. Currently, hot-swapping technology is not yet perfect; traditional hot-swapping operations can still adversely affect other components of the power system, thereby reducing the overall performance of the power system. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a power redundancy protection circuit to solve the technical problems of complex implementation, high difficulty in implementation, and high cost of existing power redundancy protection schemes. Compared with existing power redundancy protection methods, this invention uses fewer components to achieve the power redundancy protection function that previously required ADC voltage detection, CPU calculation and judgment, and CPU output, and the implementation scheme is simple and low-cost.

[0005] To achieve the above and other related objectives, this invention provides a power redundancy protection circuit, including a power status detection unit, a power switch control unit, a power redundancy protection unit, a first power supply unit, and a second power supply unit. The input terminal of the power status detection unit is connected to a first power signal and a second power signal, and is used to output a power status detection signal based on the first power signal and the second power signal. The power switch control unit is connected to the power status detection unit and is used to output a power switch control signal based on the power status detection signal. The power redundancy protection unit is connected to the power switch control unit and is used to select either the first power supply unit or the second power supply unit to supply power based on the power switch control signal, thereby achieving power redundancy protection. This invention utilizes fewer components to achieve a power redundancy protection function that previously required ADC voltage detection, CPU calculation and judgment, and CPU output.

[0006] In one embodiment of the present invention, the power state detection unit includes a voltage detection unit, a reference circuit unit, and a window comparator;

[0007] The input terminal of the voltage detection unit is connected to the first power signal, and is used to determine the voltage thresholds for power overvoltage protection and undervoltage protection based on the first power signal.

[0008] The input terminal of the reference circuit unit is connected to the second power supply signal, and is used to generate a power supply overvoltage protection reference voltage and an undervoltage protection reference voltage based on the second power supply signal;

[0009] The window comparator is connected to the voltage detection unit and the reference circuit unit. It outputs a power status detection signal by comparing the relationship between the overvoltage protection reference voltage and the voltage threshold, and the relationship between the undervoltage protection reference voltage and the voltage threshold. The power status detection signal includes a high-level signal and a low-level signal.

[0010] In one embodiment of the present invention, the overvoltage protection reference voltage is greater than the undervoltage protection reference voltage.

[0011] In one embodiment of the present invention, the window comparator includes an overvoltage protection unit and an undervoltage protection unit;

[0012] The positive terminal of the overvoltage protection unit is connected to the voltage threshold, and the negative terminal is connected to the overvoltage protection reference voltage, which is used to output the high-level signal when the voltage threshold is greater than the overvoltage protection reference voltage;

[0013] The positive terminal of the undervoltage protection unit is connected to the undervoltage protection reference voltage, and the negative terminal is connected to the voltage threshold, so as to output the high-level signal when the voltage threshold is less than the undervoltage protection reference voltage.

[0014] In one embodiment of the present invention, the window comparator is used to output the low-level signal when the voltage threshold is greater than the undervoltage protection reference voltage and less than the overvoltage protection reference voltage, thereby ensuring the stability and reliability of the system operation.

[0015] In one embodiment of the present invention, the power switch control unit includes a transistor and a first PMOS transistor; the transistor and the first PMOS transistor are used to switch between on and off states based on the power state detection signal to output the power switch control signal.

[0016] In one embodiment of the present invention, the power redundancy protection unit includes a filtering unit and a power redundancy hot standby unit.

[0017] The filtering unit includes a filter capacitor and a surge protector, used to filter the power switch control signal to generate a power switch filtered signal.

[0018] The power redundancy hot standby unit is connected to the filtering unit and is used to select the first power supply unit or the second power supply unit to supply power based on the power switch filtering signal.

[0019] In one embodiment of the present invention, the first power supply unit includes a second PMOS transistor and a resistor. The drain of the second PMOS transistor is connected to the power switch filter signal, the gate is connected to the resistor in series and then grounded, and the source is connected to the load. The second power supply unit includes a composite transistor and the resistor. The first input terminal of the composite transistor is connected to the drain of the second PMOS transistor, the second input terminal is connected to the source of the second PMOS transistor, and the output terminal is connected to the resistor in series and then grounded.

[0020] In one embodiment of the present invention, the second power supply unit is a mirror current source of the first power supply unit, used to take over the operation of the first power supply unit when the first power supply unit fails, thereby realizing high availability and continuity of the power supply system.

[0021] In one embodiment of the present invention, the first power supply unit supports hot-swapping functionality.

[0022] As described above, the power redundancy protection circuit of the present invention has the following beneficial effects:

[0023] (1) The power redundancy protection function that requires ADC voltage detection, CPU calculation and judgment and CPU output is realized with fewer components.

[0024] (2) It supports hot-swapping of power supplies, which enables high availability and continuity of the power system;

[0025] (3) It supports power overvoltage protection and undervoltage protection, ensuring the stability and reliability of system operation;

[0026] (4) The implementation plan is simple and low-cost. Attached Figure Description

[0027] Figure 1 The diagram shown is a schematic representation of a power redundancy protection circuit according to one embodiment of the present invention.

[0028] Figure 2 The diagram shown is a schematic of a window comparator in one embodiment of the power redundancy protection circuit of the present invention.

[0029] Figure 3 The diagram shown is a schematic of a power redundancy protection circuit according to an embodiment of the present invention.

[0030] Component designation explanation

[0031] 1 Power Status Detection Unit

[0032] 11 Voltage Detection Unit

[0033] 12 Reference Circuit Units

[0034] 13 Window Comparator

[0035] 131 Overvoltage Protection Unit

[0036] 132 Undervoltage Protection Unit

[0037] 2 Power switch control unit

[0038] 3 Power Redundancy Protection Unit

[0039] 31 Filtering Unit

[0040] 32 power redundancy hot standby units

[0041] 4 First Power Supply Unit

[0042] 5 Second power supply unit Detailed Implementation

[0043] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0044] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0045] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0046] Example 1

[0047] like Figure 1 As shown, in this embodiment, the power redundancy protection circuit of the present invention includes a power status detection unit 1, a power switch control unit 2, a power redundancy protection unit 3, a first power supply unit 4, and a second power supply unit 5.

[0048] The power status detection unit 1 is connected to a first power signal and a second power signal at its input terminal, and is used to output a power status detection signal based on the first power signal and the second power signal.

[0049] Specifically, the power status detection unit 1 includes a voltage detection unit 11, a reference circuit unit 12, and a window comparator 13. The input of the voltage detection unit 11 is connected to the first power signal, and it is used to determine the voltage thresholds for overvoltage protection and undervoltage protection based on the first power signal. The input of the reference circuit unit 12 is connected to the second power signal, and it is used to generate a reference voltage for overvoltage protection and an reference voltage for undervoltage protection based on the second power signal. The window comparator 13 is connected to the voltage detection unit 11 and the reference circuit unit 12, and outputs a power status detection signal by comparing the magnitudes of the overvoltage protection reference voltage and the voltage thresholds, and the magnitudes of the undervoltage protection reference voltage and the voltage thresholds. The power status detection signal includes a high-level signal and a low-level signal. The overvoltage protection reference voltage is greater than the undervoltage protection reference voltage.

[0050] like Figure 2As shown, the window comparator 13 includes an overvoltage protection unit 131 and an undervoltage protection unit 132. The positive terminal of the overvoltage protection unit 131 is connected to the voltage threshold, and the negative terminal is connected to the overvoltage protection reference voltage. It outputs a high-level signal when the voltage threshold is greater than the overvoltage protection reference voltage. The positive terminal of the undervoltage protection unit 132 is connected to the undervoltage protection reference voltage, and the negative terminal is connected to the voltage threshold. It outputs a high-level signal when the voltage threshold is less than the undervoltage protection reference voltage. The window comparator 13 outputs a low-level signal when the voltage threshold is greater than the undervoltage protection reference voltage and less than the overvoltage protection reference voltage. The window comparator 13 ensures the stability and reliability of the system operation.

[0051] The power switch control unit 2 is connected to the power status detection unit 1 and is used to output a power switch control signal based on the power status detection signal.

[0052] Specifically, the power switch control unit 2 includes a transistor and a first PMOS transistor; the transistor and the first PMOS transistor are used to switch between on and off states based on the power state detection signal to output the power switch control signal.

[0053] The power redundancy protection unit 3 is connected to the power switch control unit 2 and is used to select the first power supply unit 4 or the second power supply unit 5 to supply power based on the power switch control signal, so as to realize power redundancy protection.

[0054] Specifically, the power redundancy protection unit includes a filtering unit 31 and a power redundancy hot standby unit 32. The filtering unit 31 includes a filtering capacitor and a surge protector, used to filter the power switch control signal to generate a power switch filtered signal. The power redundancy hot standby unit 32 is connected to the filtering unit 31 and is used to select either the first power supply unit 4 or the second power supply unit 5 for power supply based on the power switch filtered signal. The first power supply unit 4 supports hot-swapping.

[0055] The first power supply unit 4 includes a second PMOS transistor and a resistor. The drain of the second PMOS transistor is connected to the power switch filter signal, the gate is connected to the resistor in series and then grounded, and the source is connected to the load. The second power supply unit 5 includes a composite transistor and the resistor. The first input terminal of the composite transistor is connected to the drain of the second PMOS transistor, the second input terminal is connected to the source of the second PMOS transistor, and the output terminal is connected to the resistor in series and then grounded.

[0056] The second power supply unit 5 is a mirror current source of the first power supply unit 4, used to take over the operation of the first power supply unit 4 when the first power supply unit 4 fails, thereby realizing the high availability and continuity of the power supply system.

[0057] Example 2

[0058] like Figure 3 As shown, the power redundancy protection circuit of the present invention includes a power status detection unit, a power switch control unit, a power redundancy protection unit, a first power supply unit, and a second power supply unit.

[0059] The power supply status detection unit includes a voltage detection unit, a reference circuit unit, and a window comparator. The voltage detection unit includes resistors R9, R14, and capacitor C9. One end of R9 serves as an input terminal for the voltage detection unit, used to receive a +5V first power supply signal; the other end is connected in series with R14 and then grounded. C9 is a filter capacitor connected in parallel across R14. By setting appropriate resistance values ​​for R9 and R14, the voltage thresholds for overvoltage and undervoltage protection can be determined. In this embodiment, the overvoltage protection voltage threshold is equal to the undervoltage protection voltage threshold.

[0060] The reference circuit unit includes series voltage divider resistors R5, R8, and R15. The first terminal of R5 serves as another input terminal of the voltage detection unit, used to connect a +3V second power supply signal. The second terminal of R5 is connected to the first terminal of R8. The first terminal of R15 is connected to the second terminal of R8, and the second terminal of R15 is grounded. By setting appropriate resistance values ​​for R5, R8, and R15, both overvoltage protection reference voltage and undervoltage protection reference voltage can be output simultaneously. In this embodiment, the overvoltage protection reference voltage is greater than the undervoltage protection reference voltage.

[0061] The window comparator includes an overvoltage protection unit and an undervoltage protection unit. It outputs a power status detection signal by comparing the overvoltage protection reference voltage with the voltage threshold and the undervoltage protection reference voltage with the voltage threshold. The power status detection signal includes a high-level signal and a low-level signal. This window comparator ensures the stability and reliability of the system operation.

[0062] The overvoltage protection unit includes U1A, R1, R13, R14, and D2, and functions as a hysteresis (Schmidt) comparator to prevent malfunctions caused by voltage fluctuations. The hysteresis voltage ΔV = Vcc * (R13 + R14) / R1, where Vcc is the +3V voltage signal input to the positive power supply terminal of U1A. The first terminal of R13 is connected to the output of the power supply detection unit, and the second terminal is connected to the input of the window comparator. Specifically, the positive terminal of the overvoltage protection unit is connected to the second terminal of R13 to input the voltage threshold, and the reverse terminal is connected to the second terminal of R5 to input the overvoltage protection reference voltage. D2 is connected to the output of the overvoltage protection unit to provide reverse protection, preventing damage to the overvoltage protection unit.

[0063] The undervoltage protection unit includes U1B, R10, R15, and D3, and functions as a hysteresis (Schmidt) comparator to prevent malfunctions caused by voltage fluctuations. The hysteresis voltage ΔV = Vcc * R15 / R10, where Vcc is the +3V voltage signal input to the positive power supply terminal of U1B. The positive terminal of the undervoltage protection unit is connected to the first terminal of R15 to receive the undervoltage protection reference voltage, and the negative terminal is connected to the second terminal of R13 to receive the voltage threshold. D3 is connected to the output terminal of the undervoltage protection unit to provide reverse protection and prevent damage to the undervoltage protection unit.

[0064] When the voltage threshold is greater than the overvoltage protection reference voltage (i.e., the voltage at the positive terminal of the overvoltage protection unit U1A is greater than the voltage at the reverse terminal), the overvoltage protection unit U1A is turned on, the undervoltage protection unit U1B is turned off, and the window comparator outputs a high-level signal. This high-level signal indicates that the input power supply voltage is outside the normal operating range. When the voltage threshold is less than the undervoltage protection reference voltage (i.e., the voltage at the positive terminal of the undervoltage protection unit U1B is greater than the voltage at the reverse terminal), the undervoltage protection unit U1B is turned on, the overvoltage protection unit U1A is turned off, and the window comparator outputs a high-level signal. The comparator outputs a high-level signal, which also indicates that the input power supply voltage is not within the normal operating range. When the voltage threshold is greater than the undervoltage protection reference voltage and less than the overvoltage protection reference voltage, that is, the voltage at the positive terminal of the overvoltage protection unit U1A is less than the voltage at the reverse terminal, and the voltage at the positive terminal of the undervoltage protection unit U1B is less than the voltage at the reverse terminal, both the overvoltage protection unit U1A and the undervoltage protection unit U1B are turned off, and the window comparator outputs a low-level signal, which indicates that the input power supply voltage is within the normal operating range.

[0065] The power switch control unit includes a first PMOS transistor Q1, transistors Q4 and Q5, resistors R2, R3, R4, R11, R12, and R16, capacitors C1, C8, and C4, and diode D1. R2 and D1 form a voltage regulator circuit to provide a stable second power supply signal to the reference circuit unit and the window comparator. C4 is a filter capacitor, and R4 is a dummy load to prevent the generation of virtual voltage. Transistors Q4 and Q5, along with the first PMOS transistor Q1, are used to switch between on and off states based on the power state detection signal to output the power switch control signal. For example, when the window comparator outputs a high-level signal due to overvoltage or undervoltage protection, Q4 is turned on, Q5 is turned off, and Q1 is turned off. Simultaneously, Q1 outputs a power-off control signal to shut down the power output and protect the downstream circuitry. When the window comparator detects that the power supply voltage is within the normal operating range and outputs a low-level signal, Q4 is turned off, Q5 is turned on, and Q1 is turned on. Simultaneously, Q1 outputs a power-on control signal to ensure normal power output.

[0066] The power redundancy protection unit is connected to the power switch control unit and includes a filtering unit and a power redundancy hot standby unit. It is used to select the first power supply unit or the second power supply unit to supply power based on the power switch control signal, so as to realize power redundancy protection.

[0067] The filtering unit includes capacitors C2, C5, and C6, and a surge protector TVS1. C6 is an input filtering capacitor used to filter the power switch control signal to generate a power switch filtered signal. C2, C5, and TVS1 form an output filtering circuit used to filter the output signals of the first power supply unit and the second power supply unit.

[0068] The power redundancy hot standby unit is connected to the filtering unit and is used to select the first power supply unit or the second power supply unit to supply power based on the power switch filtering signal.

[0069] The first power supply unit includes a second PMOS transistor Q2 and a resistor R7. The drain of the second PMOS transistor Q2 is connected to the power switch filter signal, the gate is connected in series with the resistor R7 and then grounded, and the source is connected to the load. The second power supply unit includes a composite transistor Q3 and resistors R6 and R7. The composite transistor Q3 includes two common-base PNP transistors, whose emitters are the first input terminal and the second input terminal of the composite transistor Q3, respectively. The first input terminal is connected to the drain of the second PMOS transistor Q2, and the second input terminal is connected to the source of the second PMOS transistor Q2. The collector of one of the PNP transistors is connected to the base and then connected in series with the resistor R6 and then grounded. The collector of the other PNP transistor feeds back to control the gate of Q2 and is connected in series with the resistor R7 and then grounded.

[0070] When the +5V input power supply voltage is greater than the external +5VD load voltage, the first input terminal of Q3 is turned on. Simultaneously, current flows through the freewheeling diode of the second PMOS transistor Q2 into the second input terminal of Q3, then into resistor R7, and feeds back to control the gate of Q2, forming a current source control with Q2. As the external load changes, the current through resistor R7 is adjusted to control the conduction current of Q2. When the +5V input power supply voltage is less than the external +5VD load voltage, Q2 is turned off to prevent backflow of external current, thus achieving power redundancy.

[0071] The first power supply unit supports hot-swapping. The second power supply unit is a mirror current source of the first power supply unit, used to take over the operation of the first power supply unit when it fails, thereby achieving high availability and continuity of the power system. After the power supply is replaced, the first and second power supply units work together.

[0072] In summary, the power redundancy protection circuit of this invention achieves power redundancy protection functions that previously required ADC voltage detection, CPU calculation and judgment, and CPU output using fewer components; it supports hot-swapping of the power supply, achieving high availability and continuity of the power system; it supports overvoltage and undervoltage protection, ensuring the stability and reliability of system operation; and its implementation is simple and low-cost. Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0073] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A power redundancy protection circuit, characterized in that, It includes a power status detection unit, a power switch control unit, a power redundancy protection unit, a first power supply unit, and a second power supply unit; The input terminal of the power status detection unit is connected to a first power signal and a second power signal, and is used to output a power status detection signal based on the first power signal and the second power signal. The power switch control unit is connected to the power status detection unit and is used to output a power switch control signal based on the power status detection signal. The power redundancy protection unit is connected to the power switch control unit and is used to select the first power supply unit or the second power supply unit to supply power based on the power switch control signal, so as to realize power redundancy protection. The first power supply unit includes a second PMOS transistor Q2 and a resistor R7. The drain of the second PMOS transistor Q2 is connected to the power switch filter signal, the gate is connected to the resistor R7 in series and then grounded, and the source is connected to the load. The second power supply unit includes a composite transistor Q3 and resistors R6 and R7; the first input terminal of the composite transistor Q3 is connected to the drain of the second PMOS transistor Q2, the second input terminal is connected to the source of the second PMOS transistor Q2, and the output terminal is connected in series with the resistors R6 and R7 and then grounded. The composite transistor Q3 includes two common-base PNP transistors. The collector of one PNP transistor is connected to the base, and then connected in series with resistor R6 and grounded. The collector of the other PNP transistor controls the gate of Q2, and is connected in series with resistor R7 and grounded. The second power supply unit is a mirror current source of the first power supply unit, and is used to take over the operation of the first power supply unit when the first power supply unit fails.

2. The power redundancy protection circuit according to claim 1, characterized in that, The power state detection unit includes a voltage detection unit, a reference circuit unit, and a window comparator; The input terminal of the voltage detection unit is connected to the first power signal, and is used to determine the voltage thresholds for power overvoltage protection and undervoltage protection based on the first power signal. The input terminal of the reference circuit unit is connected to the second power supply signal, and is used to generate a power supply overvoltage protection reference voltage and an undervoltage protection reference voltage based on the second power supply signal; The window comparator is connected to the voltage detection unit and the reference circuit unit. It outputs a power status detection signal by comparing the relationship between the overvoltage protection reference voltage and the voltage threshold, and the relationship between the undervoltage protection reference voltage and the voltage threshold. The power status detection signal includes a high-level signal and a low-level signal.

3. The power redundancy protection circuit according to claim 2, characterized in that, The overvoltage protection reference voltage is greater than the undervoltage protection reference voltage.

4. The power redundancy protection circuit according to claim 2, characterized in that, The window comparator includes an overvoltage protection unit and an undervoltage protection unit; The positive terminal of the overvoltage protection unit is connected to the voltage threshold, and the negative terminal is connected to the overvoltage protection reference voltage, which is used to output the high-level signal when the voltage threshold is greater than the overvoltage protection reference voltage; The positive terminal of the undervoltage protection unit is connected to the undervoltage protection reference voltage, and the negative terminal is connected to the voltage threshold, so as to output the high-level signal when the voltage threshold is less than the undervoltage protection reference voltage.

5. The power redundancy protection circuit according to claim 2, characterized in that, The window comparator is used to output the low-level signal when the voltage threshold is greater than the undervoltage protection reference voltage and less than the overvoltage protection reference voltage.

6. The power redundancy protection circuit according to claim 1, characterized in that, The power switch control unit includes a transistor and a first PMOS transistor; the transistor and the first PMOS transistor are used to switch between on and off states based on the power status detection signal to output the power switch control signal.

7. The power redundancy protection circuit according to claim 1, characterized in that, The power redundancy protection unit includes a filtering unit and a power redundancy hot standby unit. The filtering unit includes a filter capacitor and a surge protector, used to filter the power switch control signal to generate a power switch filtered signal. The power redundancy hot standby unit is connected to the filtering unit and is used to select the first power supply unit or the second power supply unit to supply power based on the power switch filtering signal.

8. The power redundancy protection circuit according to claim 1, characterized in that, The first power supply unit supports hot-swapping.

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