TWI638501B - Redundant power supply system that extends the hold time after power failure - Google Patents

Abstract

A redundant power supply system capable of prolonging maintenance time after power failure, comprising a plurality of power supplies and a plurality of sustain control circuits, wherein the power supplies are connected in parallel with each other for input capacitors connected to the load system, the power supplies and the input capacitors The connection or gate anti-backflow component is respectively connected to the DC output side of the power supply, and each of the maintenance control circuits includes an inductor, an electronic switch and a controller, and the inductor is connected in series or the gate anti-backflow component The electronic switch is connected between the series node of the inductor and the gate anti-backflow component and the DC output of each power supply, and the controller controls whether the electronic switch is turned on or not according to the size of the DC power output outputted from the DC output side, and the extension is extended. The purpose of maintaining time after power failure.

Description

Redundant power supply system that extends the hold time after power failure

This creation is about a redundant power supply system, especially a redundant power supply system that extends the hold time after a power outage.

Please refer to FIG. 7 , which illustrates a circuit architecture diagram of a typical redundant power supply system including a plurality of power supplies 30 . As is well known, each of the power supplies 30 mainly includes an AC/DC power conversion circuit and a power factor correction circuit. And the DC/DC power conversion circuit, the AC/DC power conversion circuit has an AC input side for receiving an AC power from the mains, the DC/DC power conversion circuit has a DC output side, and the DC output side is provided with a Output capacitor C ₁ .

The AC power supply is DC-converted and power-factor corrected by the AC/DC power conversion circuit, the power factor correction circuit, and the DC/DC power conversion circuit, so as to output the DC power supply Vo on the DC output side. The DC output sides of the power supplies 30 are connected in parallel to each other and to the input side of a load system 40. An ORing diode 50 is connected between the DC output side of each power supply 30 and the load system 40, and the anode end of the OR anti-countercurrent diode 50 is connected to each power supply. The DC output side of 30 is connected to the load system 40.

A typical redundant power supply system is a common output DC power supply Vo from the power supply 30, and the DC power supply Vo is supplied to the input side of the load system 40 through the forward or gate anti-countercurrent diode 50, and simultaneously to the load input capacitor C ₂ tank 40 of the input side of the system. On the premise that the AC input side of the power supply can normally receive the AC power, when any of the power supplies 30 fails and the DC power supply Vo cannot be output, the other power supply 30 can continuously supply power to the load system 40. Reach the effect of constant power. By the arrangement of the or anti-backflow diodes 50, the faulty power supply 30 can be isolated from other normal power supplies 30, and fault currents can be prevented from entering the DC output side of each of the power supplies 30.

Alternatively, the gate anti-countercurrent diode 50 may be replaced by an ORing MOS (not shown) as described above, and the gate terminal and source of the gate anti-countercurrent transistor The terminal is connected to the DC output side of each power supply 30 and the load system 40, and has a body diode between the 汲 terminal and the source terminal. A controller is electrically connected to a control end of the thyristor anti-backflow transistor.汲 extremes and source extremes, when the controller determines that the body diode is reverse biased (the source terminal voltage is greater than the 汲 extreme voltage), the controller controls the gate anti-backflow transistor to be in an open state, The faulty power supply 30 is isolated from the other normal power supplies 30, and fault current is prevented from entering the DC output side of each of the power supplies 30.

When a typical redundant power supply system suddenly stops outputting DC power, such as sudden shutdown or sudden power failure of the AC power supply, the load system 40 performs an emergency processing procedure (eg, data backup or shutdown, etc.) because it does not receive the DC power supply Vo. At this time, the input capacitor C _{2 on} the input side of the load system 40 releases the energy storage. As the stored energy is continuously released, the terminal voltage of the input capacitor C ₂ gradually decreases. When the load system 40 detects that the terminal voltage of the input capacitor C ₂ is lower than a threshold voltage, the load system 40 is directly turned off. The duration from when the load system 40 does not receive the DC power supply Vo and until the terminal voltage of the input capacitor C ₂ is lower than the threshold voltage is referred to as a sustain time. Obviously, when the load system 40 is turned off, if the emergency processing program has not been executed, the load system 40 will be improperly shut down and cause bad consequences (for example, data loss).

A typical improvement can be used in each of the power supplies 30 to select an output capacitor C ₁ having a larger capacity, so that the input capacitor C _{2 of} the load system 40 can extract the energy of the output capacitor C ₁ after power-off, delaying the input capacitor. Discharge of C ₂ to extend the hold time. However, the use of a large-capacity output capacitor C ₁ in each power supply 30 is not only more expensive, but also bulkier, which also causes inconvenience in the overall mechanical design of a typical redundant power supply system, and is only for a short extension. The large-capacity output capacitor C ₁ is used to maintain the limited effect of time, which is not cost.

In view of this, the main purpose of this creation is to provide a redundant power supply system that can prolong the maintenance time after power failure, based on the circuit architecture of a typical redundant power supply system, without switching to a larger capacity output capacitor. Under the premise, the maintenance time can be effectively extended.

The present invention can extend a redundant power supply system for maintaining the time after power-off for an input capacitor connected to a load system, the redundant power supply system comprising: a plurality of power supplies connected in parallel with each other for connecting the input capacitors At least one or anti-backflow component is connected between the DC output side of the power supply and the input capacitor, and the DC output side has an output capacitor; a plurality of sustain control circuits respectively corresponding to the DC connected to the power supply Between the output side and the load system, each of the sustain control circuits includes: at least one inductor connected in series to the at least one or anti-backflow component; at least one electronic switch connected to the inductor and the at least one or anti-backflow a series connection node of the component and a DC output side of each of the power supplies; and a controller connecting a DC output side of each of the power supplies and a control end of the at least one electronic switch to determine the DC output side Whether the output DC power is lower than a lower limit, and controlling whether the at least one electronic switch is turned on or not.

According to the present invention, when the power supplies are in normal operation, in each of the power supply and maintenance control circuits, the controller can determine the output of the DC power supply, and the controller controls the electronic switch to be in an open state. The DC power output from the power supply can be transmitted to the load system. When the power supply suddenly stops operating, the controller can determine that there is no output of the DC power supply, and the controller controls the electronic switch to be in an intermittent conduction state, and the output capacitors of the respective power supply suppliers and the respective inductor pairs The input capacitor of the load system releases energy such that the terminal voltage of the input capacitor is maintained for a period of time to decrease, or decreases at a slower rate, thereby extending the hold time. For example, the maintenance time provided by the present application can be typical. The redundant power supply system can provide more than 1.5 times the maintenance time, allowing the load system to have more time to complete the emergency processing after power failure.

On the other hand, compared with large-capacity capacitors, the proposed maintenance control circuit only contains electronic components such as controllers, inductors, diodes or transistors, and the cost of maintaining the control circuit is lower and the volume is small. Smaller, it will not cause the inconvenience of the overall system design of the system, overcoming the problems caused by the use of large-capacity capacitors as described in the prior art.

Referring to FIG. 1, the redundant power supply system 10 for extending the maintenance time after power-off is provided for the input capacitor C _SYS connected to the load system L, and the DC power supply V _{DC is} output from the redundant power supply system 10 to the load system L. . When the load system L detects that the terminal voltage of the input capacitor C _SYS is lower than a threshold voltage, the load system L is directly turned off. The duration from when the load system L does not receive the DC power source V _DC and the terminal voltage of the input capacitor C _SYS is lower than the threshold voltage is referred to as a sustain time.

The redundant power supply system 10 includes a plurality of power supplies 11 , at least one ORing anti-backflow component 12 corresponding to each of the power supplies 11 , and a plurality of sustain control circuits 13 . The embodiment shown in FIG. 1 is exemplified by two power supplies 11 as an example, but is not limited thereto. Alternatively, the present creation may be constituted by the power supply 11, the ORing anti-backflow element 12, and the sustain control circuit 13.

As shown in FIG. 1, the power supplies 11 are connected in parallel with each other to connect the input capacitors C _{SYS of} the load system L to form a connection structure of many to one (ie, a plurality of power supplies 11 to one load system L). Each of the power supplies 11 has a DC output side, and the DC output side of each of the power supplies 11 is connected to the load system L through the OR gate anti-backflow element 12. For example, each of the power supply 11 mainly includes an AC/DC power conversion circuit, a power factor correction circuit, and a DC/DC power conversion circuit. The AC/DC power conversion circuit has an AC input side, and the AC input. The side receives an AC power from the mains, the DC/DC power conversion circuit has the DC output side to output the converted _DC power V _DC , and the DC power V _DC output by each of the power supplies 11 passes through the OR gate The backflow prevention element 12 is provided to the load system L. The sustain control circuits 13 are respectively connected to the DC output sides of the power supplies 11 to form a one-to-one connection structure (ie, one power supply 11 to one sustain control circuit 13).

The maintenance control circuits 13 are respectively connected between the DC output side of the power supply 11 and the load system L. Referring to the embodiment shown in FIG. 2 to FIG. 6, only the plurality of power supplies 11 are included. For example, the power supply 11 and the corresponding one of the power supply 11 have a power terminal 111 and a ground terminal 112. The power terminal 111 and the ground terminal An output capacitor C _DC is provided between 112. Each of the sustain control circuits 13 includes at least one inductor 131, at least one electronic switch 132, and a controller 133.

In the first embodiment shown in FIG. 2, each of the sustain control circuits 13 includes an inductor 131, an electronic switch 132 and a controller 133, and the DC output side of each of the power supplies 11 is connected to one or the anti-backflow. Element 12. The inductor 131 is connected in series to the OR gate anti-backflow element 12, wherein one end of the inductor 131 is connected to the power terminal 111, and the OR gate anti-backflow element 12 is connected to the input capacitor _{CSYS of} the load system L. The electronic switch 132 Connected between the inductor 131 and the series node n of the or gate anti-backflow element 12 and the ground terminal 112. The electronic switch 132 can be a transistor having a first end, a second end, and a control end. For example, the first end can be a drain, and the second end can be a source. The control terminal may be a gate terminal, the first terminal is connected to the series node n, and the second terminal is connected to the ground terminal 112. The gate anti-backflow component 12 may be an anti-backflow diode (ORing diode). Its anode end is connected to the other end of the inductor 131, and its cathode end is connected to the input capacitor C _{SYS of} the load system L. The controller 133 is connected to the power supply 11 and the control end of the electronic switch 132 to control whether the electronic switch 132 is turned on or not according to whether the DC output side outputs the DC power supply V _DC .

For example, as shown in FIG. 2, the controller 133 can be connected to the power terminal 111 to detect the size of the DC power source V _DC . When the controller 133 determines that the DC power source V _{DC is} greater than or equal to a lower limit value, It is determined that there is an output of the DC power source V _DC ; conversely, when the controller 133 determines that the DC power source V _{DC is} lower than the lower limit value, it is determined that there is no output of the DC power source V _DC . Alternatively, the controller 133 may be further connected to the AC input side of the power supply 11 via a photocoupler 134 to directly detect whether there is an input of the AC power supply V _AC . The input of V _AC , of course, does not have the output of the DC power supply V _DC .

The circuit operation of the first embodiment of the present invention is described below by way of an example. Referring to FIG. 1 and FIG. 2, when all the power supplies 11 are in normal operation, the power supplies 11 simultaneously output a DC power supply V _DC for supply to the same. Load system L. In each of the power supply 11 and the maintenance control circuit 13, when the controller 133 determines that there is an output of the DC power supply V _DC , the controller 133 controls the electronic switch 132 to be in an open state. At this time, the DC power supply V _{The DC} reaches the load system L through the inductor 131 and the OR gate anti-backflow element 12, and the output capacitor C _{DC of} each of the power supply 11 and the input capacitor C _{SYS of} the load system L are stored according to the DC power supply V _DC The inductor 131 can filter the switching ripple and high frequency noise of the DC power source V _DC .

When all of the power supply 11 to stop working abruptly, the sudden shutdown e.g. V _AC or AC power to jump suddenly, all of the DC power source V _DC power supply 11 does not output, the output capacitor C _DC release of stored energy caused by the terminal voltage Decreasing, so that in each group of power supply 11 and maintenance control circuit 13, when the controller 133 determines that the DC power source V _{DC is} lower than the lower limit value, the controller 133 controls the electronic switch 132 to be intermittent. In the on state, for example, the controller 133 can output a Pulse Width Modulation (PWM) signal to the control terminal of the electronic switch 132. Referring to FIG. 2, the output capacitor C _DC of the power supply 11 , the inductor 131 , the or anti-backflow component 12 , the electronic switch 132 and the controller 133 form a boost converter. The working principle of the booster circuit is known to the public and will not be described in detail here.

Therefore, compared with a typical redundant power supply system without a booster circuit, the present invention is to discharge the stored energy to the output capacitor C _DC through the booster circuit when all the power supplies 11 stop outputting the DC power supply V _DC The input capacitor C _{SYS of} the load system L allows the input capacitor C _{SYS to} receive the boosted voltage, so that the terminal voltage of the input capacitor C _SYS is maintained for a period of time to be decremented, or decreased at a slower speed, thereby extending the The time is maintained to allow the load system L to have more sufficient maintenance time to complete the emergency processing procedure after the power is turned off.

Referring to the second embodiment shown in FIG. 3, in each of the power supply 11 and the maintenance control circuit 13, each of the power supplies 11 is connected to the load system L through a plurality of or anti-backflow elements 12, the maintenance control Circuit 13 includes a plurality of inductors 131, a plurality of electronic switches 132, and a controller 133. The inductors 131 are respectively connected in series to the OR gate anti-backflow component 12, and the electronic switches 132 are respectively connected to the series node n of the inductors 131 and the gate anti-backflow components and the power supply 11 Between the DC output sides. Specifically, one end of each of the inductors 131 is connected to the power terminal 111, and each of the gate anti-backflow elements 12 is connected to the input capacitor C _{SYS of} the load system L. Each of the electronic switches 132 is connected to each of the inductors 131 and Between the series node n of the OR gate anti-backflow element 12 and the ground terminal 112, the controller 133 is connected to the control terminals of the electronic switches 132. Therefore, the output capacitor C _DC of the power supply 11 , the or the anti-backflow prevention component 12 , the inductors 131 , the electronic switches 132 , and the controller 133 can form a complex boost after the AC power is cut off. Circuit.

It should be noted that, in the second embodiment shown in FIG. 3, when the controller 133 performs a boosting operation, the controller 133 may adopt a phase delay method to evenly distribute the conduction phase difference of the electronic switches 132. For example, when there are m electronic switches 132, the phase difference of each of the two electronic switches 132 is Thereby, the current released by the output capacitor C _DC can be evenly distributed in each boosting circuit to achieve the effect of current sharing, so that the inductor 131 and the gate anti-backflow component 12 in each boosting circuit are The current tolerated is small and the design of the inductor 131 is also simpler.

The foregoing anti-backflow element 12 of the first and second embodiments is exemplified by an anti-backflow diode (ORing diode). Further, another embodiment of the or gate anti-backflow element 12 may be a transistor element (ORing). MOS). For example, referring to FIG. 4, the gate anti-backflow component 12 has a first end, a second end, and a control end, and the first end and the second end are respectively Drain or source terminals. (Source), the control terminal may be a gate terminal, the control terminal is connected to an output end of the controller 133, and the first end and the second end of the gate anti-backflow component 12 are respectively connected to the controller 133 The input end is configured for the controller 133 to detect the terminal voltage Va of the first end and the terminal voltage Vb of the second end; the first end and the second end have a body diode 121, The anode end of the body diode 121 faces the DC output side of each of the power supplies 11, and the cathode end faces the load system L. Specifically, referring to the embodiment shown in FIG. 4, the anode end of the body diode 121 is connected to the inductor 131, and the cathode end thereof is connected to the input capacitor C _{SYS of} the load system L.

Referring to FIG. 4, when the controller 133 determines that there is an output of the DC power source V _DC , the controller 133 controls the electronic switch 132 to be in an open state, and controls the OR gate anti-backflow element 12 to be in an on state. The DC power source V _{DC is} delivered to the load system L. On the other hand, when the controller 133 determines that there is no output of the DC power source V _DC , the controller 133 controls the electronic switch 132 to be in a synchronous intermittent conduction state with the OR gate anti-backflow element 12 to make the power supply 11 The output capacitor C _DC , the inductor 131 , the body diode 121 , the electronic switch 132 and the controller 133 form a boost converter. On the other hand, when the controller 133 determines that the body diode 121 is in the reverse bias (ie, Va>Vb), indicating that the fault current is passed, the controller 133 immediately controls the gate or the backflow prevention. The component 12 is in an open state to isolate the electrical supply 11 from fault currents entering the DC input side of the power supply 11. In this embodiment, compared with the technology of the prior art or the anti-backflow transistor and the controller, the present embodiment only further provides electronic components such as the inductor 131 and the electronic switch 132 in terms of hardware. The embodiment hardware is inexpensive.

For other possible embodiments of the sustain control circuit, please refer to FIG. 5. In each of the sustain control circuits, one end of the inductor 131 is connected to the input capacitor C _SYS , and the gate anti-backflow element 12 is connected to the power supply 11 . The power terminal 111 is connected between the inductor 131 and the series node n of the OR gate anti-backflow element 12 and the ground terminal 112 of the power supply 11 . For example, the OR gate anti-backflow element 12 can be a body diode of a diode or a transistor having an anode terminal connected to the power terminal 111 and a cathode terminal connected to the inductor 132. The electronic switch 132 can be a body diode of a diode or a transistor, and the cathode end and the anode end are respectively connected to the series node n and the ground terminal 112. Therefore, the output capacitor C _DC , the or gate anti-backflow element 12 , the inductor 132 , the electronic switch 132 and the controller (not shown) can form a step-down circuit after the AC power is cut off (Buck Converter), the working principle of the step-down circuit has been known to the public and will not be described in detail here.

In each of the sustain control circuits, each of the sustain control circuits may further include a bypass switch, which is exemplified in FIG. 6, but not limited to the embodiment shown in FIG. 6, the bypass switch 14 is connected to each of the power supplies. Between the power terminal 111 of the supplier 11 and the input capacitor C _{SYS of} the load system L, the bypass switch 14 is connected in parallel with the OR gate anti-backflow element 12 and the inductor 131 connected in series; the controller A control terminal of the bypass switch 14 is connected. For example, the bypass switch 14 can be a transistor having a first end, a second end, and a control end, and the first end and the second end can be Drain or source extremities, respectively. (Source), the control terminal can be a gate.

When the controller determines that the power supply 11 can output the DC power supply V _DC , the controller turns on the bypass switch 14 and controls the electronic switch 132 to be in an open state, so that the DC power output of the power supply 11 can be The bypass switch 14 directly reaches the load system L. Since the DC power source does not pass the gate anti-backflow component 12 and the inductor 131, no loss is caused; otherwise, when the controller determines the power supply 11 When the DC power supply is not output, the controller controls the bypass switch 14 to be in an open state, and intermittently turns on the electronic switch 132 to implement the step-down circuit to extend the maintenance time.

In summary, the present invention is based on the circuit architecture of a typical redundant power supply system. Referring to FIG. 2 to FIG. 6, each power supply 11 is connected to a maintenance control circuit 13 provided by the maintenance control circuit 13. The function of extending the sustain time is extended, and the sustain control circuit 13 includes only electronic components such as a controller, an inductor, a diode, or a transistor, and the cost of maintaining the control circuit 13 is higher than that of a large-capacity capacitor. Low, and smaller, does not cause inconvenience in the overall design of the system, so the overall creation of the creation can be balanced in terms of cost and efficiency.

10‧‧‧Redundant power supply system

11‧‧‧Power supply

111‧‧‧Power terminal

112‧‧‧ Grounding terminal

12‧‧‧ or gate anti-backflow element

121‧‧‧ Body diode

13‧‧‧Maintenance control circuit

131‧‧‧Inductors

132‧‧‧Electronic switch

133‧‧‧ Controller

134‧‧‧Optocoupler

14‧‧‧Bypass switch

30‧‧‧Power supply

40‧‧‧Load system

50‧‧‧ or gate anti-countercurrent diode

C _DC ‧‧‧ output capacitor

V _DC ‧‧‧DC power supply

N‧‧‧ tandem node

L‧‧‧ load system

C _SYS ‧‧‧ input capacitor

C ₁ ‧‧‧ output capacitor

C ₂ ‧‧‧ input capacitor

Vo‧‧‧DC power supply

Figure 1: Schematic diagram of the circuit architecture of a redundant power supply system that extends the maintenance time after power failure. Figure 2 is a circuit diagram (1) of an embodiment of a power supply and a corresponding sustain control circuit of the present invention. Figure 3 is a circuit diagram (2) of an embodiment of a power supply and a corresponding sustain control circuit of the present invention. Figure 4 is a circuit diagram (3) of an embodiment of a power supply and a corresponding sustain control circuit of the present invention. Figure 5 is a circuit diagram (4) of an embodiment of a power supply and a corresponding sustain control circuit of the present invention. Figure 6 is a circuit diagram (5) of an embodiment of a power supply and a corresponding sustain control circuit of the present invention. Figure 7: Schematic diagram of the circuit architecture of a typical redundant power supply system.

Claims (11)

A redundant power supply system capable of extending a hold time after a power failure, for connecting an input capacitor of a load system, the redundant power supply system comprising: a plurality of power supplies connected in parallel with each other for commonly connecting the input capacitors Connecting at least one or anti-backflow component between the DC output side of the power supply and the input capacitor, and having an output capacitor on the DC output side; a plurality of sustain control circuits, each of the sustain control circuits being connected to the corresponding one Between the DC output side of the power supply and the load system, each of the maintenance control circuits includes: at least one inductor connected in series to the at least one or anti-backflow component; at least one electronic switch connected to the inductor and the at least a series connection between the gate anti-backflow component and the DC output side of each of the power supplies; and a controller connecting the DC output side of each of the power supplies and a control end of the at least one electronic switch to determine Whether the DC power outputted by the DC output side is lower than a lower limit, and controlling the at least one electronic switch to be turned on No; wherein when the controller determines the DC output side of the DC power output is not less than the lower limit value, the controller controls the at least one electronic switch is open. A redundant power supply system capable of extending the maintenance time after power-off as described in claim 1, wherein the at least one or anti-backflow component connected between the DC output side of each of the power supplies and the input capacitor is a single or gate The anti-backflow component; in each of the sustain control circuits, the at least one inductor is a single inductor, and the at least one electronic switch is a single electronic switch. A redundant power supply system capable of extending the maintenance time after power-off as described in claim 1, wherein the at least one or anti-backflow element connected between the DC output side of each of the power supplies and the input capacitor includes a plurality of gates or gates Anti-backflow component; In each of the sustain control circuits, the at least one inductor includes a plurality of inductors respectively connected in series to the OR gate anti-backflow component; the at least one electronic switch includes a plurality of electronic switches, and the electronic switches are respectively connected to The inductors are connected between the series node of the OR gate anti-backflow elements and the DC output side of each of the power supplies. The redundant power supply system capable of extending the maintenance time after power-off according to any one of claims 1 to 3, wherein each of the power supply has a power supply end and a grounding The output capacitor is connected between the power terminal and the ground. In each of the sustain control circuits, one end of the inductor is connected to the power terminal, and the OR gate anti-backflow component is connected to the input capacitor. An electronic switch is connected between the series connection of the inductor and the OR gate anti-backflow component and the ground, such that the output capacitor, the OR gate anti-backflow component, the inductor, the electronic switch and The controller forms a boost circuit. The redundant power supply system capable of extending the maintenance time after power-off according to any one of claims 1 to 3, wherein each of the power supply has a power supply end and a grounding The output capacitor is connected between the power terminal and the ground terminal. In each of the sustain control circuits, one end of the inductor is connected to the input capacitor, and the OR gate anti-backflow component is connected to the power terminal. An electronic switch is connected between the series connection of the inductor and the OR gate anti-backflow component and the ground, such that the output capacitor, or the gate anti-backflow component, the inductor, the electronic switch and The controller forms a step-down circuit. A redundant power supply system capable of extending the time after power-off as described in claim 4, wherein in each of the power supplies, the or-gate anti-backflow element is a diode, and the anode terminal of the diode is connected In the inductor, the cathode end of the diode is connected to the input capacitor. A redundant power supply system capable of extending the maintenance time after power-off according to claim 4, wherein in each of the power supplies, the or-gate anti-backflow component is a transistor component, and one of the transistor components The control terminal is connected to the controller. The transistor component has a body diode. The anode end of the body diode is connected to the inductor, and the cathode end of the body diode is connected to the input capacitor. The redundant power supply system capable of extending the maintenance time after power-off as described in claim 5, further comprising a bypass switch connected to the power supply end of each of the power supply terminals in each of the maintenance control circuits Between the input capacitors, the bypass switch is connected in parallel with the or-gate anti-backflow element and the inductor connected in series; the controller is connected to a control end of the bypass switch. A redundant power supply system capable of extending the maintenance time after power-off according to claim 5, wherein in each of the power supplies, the or-gate anti-backflow element is a diode, and an anode end of the diode is connected to the anode At the power terminal, the cathode end of the diode is connected to the inductor. A redundant power supply system capable of extending the time after power-off as described in claim 5, wherein in each of the power supplies, the or-gate anti-backflow component is a transistor component, and a control terminal of the transistor component is connected In the controller, the transistor component has a body diode, an anode end of the body diode is connected to the power terminal, and a cathode end of the body diode is connected to the inductor. The redundant power supply system capable of extending the maintenance time after the power failure is as described in claim 1, wherein the number of the maintenance control circuits is m, and the number of the electronic switches of the maintenance control circuits is also m, and each The conduction phase difference between the two electronic switches is 360°/ m .