JP2002369379A - Redundant power supplying system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a redundant power supplying system that includes a plurality of power supplies connected in parallel and guarantees continuous power supply even if one of those power supplies is caused to have a breakdown. SOLUTION: This system is provided with a plurality of power supplies each having an output connected in parallel to a load via an insulating device. Each power supply has a current sensor that senses a current in the output of the power supply and a current feedback circuit that adjusts the output current of each power supply in such a way as to almost equalize the output currents of all the power supplies connected to the load via each insulating device. Furthermore, each power supply has a local group for feeding back a voltage at the upstream point of the insulating device for each power supply, a remote group for feeding back a voltage at the downstream point of the insulting device of each power supply, and a controller that selectively controls the local and remote groups of each power supply and selects a feedback voltage impressed to each power supply.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply system for supplying power to a load, and more particularly, to a power supply system including a plurality of power supplies connected in parallel, wherein one of them is continuously operated even if one of them fails. The present invention relates to a redundant power supply system that guarantees power supply.

[0002]

2. Description of the Related Art A redundant power supply system typically includes two or more power supplies having outputs connected in parallel to a load via isolation devices such as diodes and transistors. This isolator is controlled by a controller to connect or disconnect each power supply to or from the load, and if one of these power supplies fails, it is quickly and automatically disconnected and reverse current is applied to the failed power supply. It is designed to prevent it from flowing. Each power supply further includes a voltage feedback circuit controlled by the controller to adjust the output voltage of the individual power supply. Examples of known redundant power supply systems are described in U.S. Pat. Nos. 4,860,188 and 5,672,958.

One of the challenges in such a redundant power supply system is to equalize the current flowing through the active power supplies so that all active power supplies share the load equally. Another problem with such a redundant power supply system is that of adjusting the output voltage of the system with respect to the load. This is because the output voltages of the individual power supplies always have a slight difference. Yet another challenge in such a redundant power supply system is the problem of overcurrent, which is created when the power supply is suddenly disconnected and impairs the reliable operation of the electrical equipment supplied by the power supply system. .

[0004]

It is an object of the present invention to provide a redundant power supply system which has one or more of the above advantages.

[0005] Accordingly, one aspect of the present invention comprises a plurality of power supplies having outputs connected in parallel to the load, each of these power supplies electrically connecting or disconnecting each power supply to the load. A redundant device for supplying power to a load having a controllable insulating device, a voltage feedback circuit for adjusting the output voltage of each power supply, and a controller for controlling the insulating device and the voltage feedback circuit of each power supply A power supply system, wherein each of these power supplies further includes a current sensor that senses a current at the output of each power supply, and an output current of all power supplies connected to the load via respective isolation devices. A current feedback circuit that adjusts the output current of each power supply so as to make the power supply uniform.

According to other features in the preferred embodiment described below, all current feedback circuits are connected together in parallel via a common current sharing bus.

Another aspect of the present invention comprises a plurality of power supplies having outputs connected in parallel to the load, each of these power supplies electrically connecting or disconnecting each power supply to the load. A redundant power supply for supplying power to a load having a controllable insulating device, a voltage feedback circuit for adjusting an output voltage of each power supply, and a controller for controlling the insulating device and the voltage feedback circuit of each power supply A local loop for each of the voltage feedback circuits to feed back a voltage at an upstream point of the isolation device for each power supply, and a remote loop for feeding back a voltage at a downstream point of the isolation device for each power supply. Each of the control devices selectively selects a local and a remote loop of each of the power supply devices. Gyoshi, characterized in that is adapted to select a feedback voltage applied to each power.

[0008] Another feature of the preferred embodiment of the present invention described below is that the controller of each of the power supplies is configured such that when the voltage at the upstream point is lower than the voltage at the downstream point, Thus, the local and remote loops of each power supply are controlled so as to feed back the voltage at the upstream point.

[0009] In a first preferred embodiment, both the local loop and the remote loop include analog switches controlled by a controller in each power supply. In the second embodiment, the local loop includes an analog switch. However, when the analog switch of the local loop is closed, the local loop has a resistance substantially higher than the resistance of the local loop in the power supply. The remote loop feeds back voltage from the downstream point only when an analog switch in each of the local loops is opened.

According to other features in the described preferred embodiment, the system comprises a common bus connecting remote loops of all power supplies in parallel at a point adjacent to the load.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <System of FIG. 1> FIG.
Shows a redundant power supply system provided with a plurality of power supplies denoted by PS-n, all of which are connected in parallel to a common load denoted by _RL . Power PS
Elements of -1 are indicated by numbers starting from 100, and elements in the power supply PS-2 are indicated by numbers starting from 120. The system of the present invention can include any number of power supplies connected in parallel, depending on the degree of redundancy depending on the particular application.

[0012] Each power supply, the square indicated by a dotted line in order to control the voltage supply source indicated by the terminal V _in, each power in order to supply in a redundant manner the power to a common load R _L block (For example, 100, 120).

That is, the power supply PS-1 is a power regulator (power
regulator) 101, a current sensor 102, and an insulation device 103, which is selectively controlled to selectively connect the power supply to the common load RL. ing. For example, the isolation device 103 may be a diode that is forward biased to connect the power supply to the load and reverse biased to disconnect the power supply from the load. Further, the insulating device 103 may be a transistor such as a metal oxide semiconductor field effect transistor (MOSFET). This type of transistor, while more effective,
It will be more expensive.

The current sensor 102 senses the current at the output of the power supply and outputs the power of the power supply so as to make the output currents of all the power supplies connected to the load _RL through the respective insulating devices 103 substantially equal. It controls the current feedback circuit 104 for adjusting the current.

The power supply PS-1 further includes a controller (control device) 10 for controlling the insulating device 103 of the power supply and controlling a feedback voltage circuit for feeding back a voltage to the power regulator 101 of the power supply.
Five. This voltage feedback circuit is composed of two loops. The first loop is called a "local loop" and includes an analog switch 106, and the second loop is called a "remote loop" and includes an analog switch 107. The local loop controlled by the analog switch 106 corresponds to the insulating device 1
03 at the upstream point 108
Feedback to 1 On the other hand, the analog switch 10
The remote loop controlled by 7 feeds back to the power conditioner 101 a voltage from a point 112 downstream of the isolator 103 and close to the common load _RL , as described in more detail below.

The controller 105 is connected to the insulation device 10.
The two analog switches 106 and 107 are selectively controlled in accordance with the relationship between the voltage at a point 109 immediately downstream of 3 and the voltage at a point 108 upstream of the insulating device 103. That is, as described in more detail below, if the voltage at point 109 drops below the voltage at point 108 during operation of the system, the controller 1
In step 05, the analog switch 106 is turned off and the analog switch 107 is turned on. As a result, the feedback voltage to the regulator 101 will be applied from point 112, ie, from a point downstream of the isolator 103 and close to the common load _RL . On the other hand, when the voltage at the point 108 on the upstream side of the insulating device 103 becomes lower than the voltage at the point 109 (as described below, this state may be the no-load condition or the power supply PS-1 has failed as described below). The controller 105 turns on the analog switch 106 and turns off the analog switch 107. As a result, the feedback voltage to the power regulator 101 is
03 from the upstream point 108 through the local loop. In the latter case (that is, when there is no load or the power supply PS-1 fails as described below), the controller 105 also controls the insulating device 103 and switches it to the OFF state.

The output of power supply PS-1 appears at point 111 in FIG. 1 and is connected to output load bus 155. This bus 115 provides a common output for the power supply PS-2 and other power supplies in the redundant current supply system. This bus 115 is connected to a ground connection point 116 near the load _RL . Connection point 1 near this load _RL
16 is also connected to a common voltage feedback bus 114 for all power supplies. This bus 114
The feedback voltage is provided to the remote loop of each power supply controlled by each remote loop analog switch, such as analog switch 107 in power supply PS-1.

The illustrated system further includes a common current sharing bus 113 common to all power supplies and connected to the current feedback circuits of the individual power supplies. That is, as shown in FIG. 1, the current feedback circuit 104 of the power supply PS-1 is connected to the common current sharing bus 113 via the terminal 110.

All other power supplies of the redundant system shown in FIG.
3, 114 and 115. That is, it can be seen that the power supply PS-2 includes a power regulator 121, a current sensor 122, an isolation device 123, and a current feedback circuit 124. Power supply PS-2
Further includes a controller 125 for controlling the two analog switches 126 and 127, respectively. This controller 125 is the controller 10 of the power supply PS-1.
As described above in relation to No. 5, it is controlled by the voltage at the point 128 upstream of the insulation device 123 and at the point 129 downstream of the insulation device. The power supply PS-2 further includes a terminal 130 connecting its current feedback circuit 124 to a common current sharing bus 113 and a terminal 131 connecting its output to a common output load bus 115.
And a terminal 132 for connecting the load-voltage feedback bus 114 to the power regulator 121 via an analog switch 127 for voltage feedback.

<Normal Mode Operation> In the normal mode operation, all the power supplies PS-1 to PS-n are connected in parallel to the load _RL via their individual insulating devices 103 and 123. And equally share the load current supplied to the load. The equal sharing of the current is controlled by the current sensors (102, 122) of the individual power supplies. These current sensors control the respective current feedback circuits 104 and 124 all connected together by a common current sharing bus 113.

During this normal mode of operation, each power supply supplies a current to the common load _RL , causing a voltage drop on both sides of the individual power supply isolation device. That is, the power supply PS-1
Here, the voltage drop at the insulation device 103 causes the voltage at the point 109 to be lower than the voltage at the point 108.
In such a case, the controller 105 turns off the analog switch 106 and sets the analog switch 1
07 is turned ON, and the feedback voltage to the power regulator 108 is applied from the bus 114, the terminal 112, and the analog switch 107 via the remote loop. Therefore, in such a case, the feedback voltage applied to the power regulator 101 is a voltage at a point downstream of the insulating device 103, that is, a voltage from a point 116 adjacent to the load _RL . This voltage at the point 116 adjacent to the load _RL will therefore be used as a feedback voltage to regulate the power regulators 101, 121 of all power supplies.

<Operation in No-Load State> When the load _RL is OFF, no current is supplied from the power supply, so that no current flows through any of the insulating devices 103 and 123. As a result, the voltage on both sides of the isolation device in each power supply is the same. However, as described above, the output voltage of each power supply is very small, but there are always some differences, so the voltage at the output of the isolator of one power supply among the plurality of power supplies is Slightly higher than the voltage. The output points 109, 1 of these power supply insulation devices
29 are all connected together via a common load bus 115, so that the voltage at the output of each isolator (except for the power supply with the highest output voltage) is higher than the voltage at the input. Will be slightly larger. For example, point 109 will have a voltage that is slightly greater than the voltage at point 108. The difference in this voltage is
When sensed by the controller 105, the analog switch (eg, 106) in the local loop is turned on, and the analog switch (eg, 107) in the remote loop is turned off. As a result, the feedback voltage applied to the power conditioner is
From the point 108 on the upstream side of. The microcontroller turns off these power supply isolators where the voltage downstream of the isolators is greater than the voltage upstream.
You may make it.

Accordingly, in this state, none of the power supplies draws current, and the voltage applied to the load becomes the voltage of the power supply having the largest output voltage.

<Operation when one or more power supplies fail> When one or more power supplies among a plurality of power supplies connected in parallel fail, each controller 105, 125
Detects the state, activates each of the insulating devices 103 and 123, and disconnects the power supply from the load. The remaining power supply or power supplies the load. This load current is shared equally by all active power supplies.

For example, assume that power supply PS-1 has failed.
When such a situation occurs, the insulation device 103 of the power supply
At a point 109 immediately downstream of the isolator is greater than the voltage at a point 108 immediately upstream of the isolator.
This is because the voltage at the point 109 is the voltage of the operating power supply having the highest output voltage, as described in the operation of the no-load state. Further, as described above, when the voltage at the point 109 becomes higher than the voltage at the point 108, the controller 105 operates the insulating device 103 to disconnect each power supply PS-1 from the load. Further, the controller 105 controls the two analog switches 106 and 107 in the same manner as in the above-mentioned no-load state, but this is important because the power supply PS-1 is already disconnected from the load. Not that.

However, the corresponding controller 125 in the power supply PS-2 will determine that the insulation device 1 is higher than the voltage at the point 128 upstream of the insulation device 123.
The analog switch 126 is turned on and the analog switch 127 is turned off, similarly controlled by the voltage at the downstream point 129 of 23. Therefore, the voltage at the upstream point 128 of the insulating device 123 is
The power supply is supplied to the power regulator 121 for the power supply PS-2 via a local loop including 26, and adjusts the voltage of the power supply. The same is true for the other active power supplies in this redundant power supply system.

Therefore, during this state, the largest output power
The working power supply with pressure is the load R _LVoltage applied to
Control and ensure that the current supplied to the load is
It will be shared uniformly by sources.

<Modification of FIG. 2> FIG. 2 shows a power supply system substantially similar to the redundant power supply system described with reference to FIG. 1, so that the same reference is used to identify the corresponding parts. Numbers are used.

In the modified example of FIG. 2, instead of the analog switches 107 and 127 described with reference to FIG.
stituting resistors) 207 and 227. The resistance value of the resistors 207 and 227 is
When the analog switches 106 and 126 are closed, the voltages fed back from the bus 114 via the individual remote loops become effective only when the analog switches 106 and 126 are switched.
Is considerably larger than the resistance value of the local loop including.

In all other respects, the configuration and operation of the system of FIG. 2 is substantially the same as that described for FIG.

While the invention has been described with reference to two preferred embodiments, it should be understood that they have been presented by way of example only, and that there are many improvements and modifications and other applications of the invention. .

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating one embodiment of a redundant power supply system according to the present invention.

FIG. 2 is a block diagram showing a modified example of the redundant power supply system of FIG. 1;

[Explanation of symbols]

 100 (120) Square block shown by dotted line 101 (121) Power regulator 102 (122) Current sensor 103 (123) Isolator 104 (124) Current feedback circuit 105 (125) Controller 106 (126) Analog switch 107 (127) Analog switch 108 (128) (upstream of the insulation device) point 109 (129) (downstream of the insulation device) point 111 point 113 bus 114 common voltage feedback bus 115 bus 116 point 130 terminal 207, 227 replacement transistor

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5G065 AA00 DA01 HA01 HA07 HA20 JA01 JA07 LA01 LA02 MA10 NA02 NA04 NA06 5H410 BB06 CC05 EA37 FF05 FF25 LL11

Claims (13)

[Claims] 1. A controllable isolator comprising: a plurality of power supplies having an output connected in parallel to a load, each of the plurality of power supplies being electrically connected and disconnected from a load. A redundant power supply system for supplying power to a load including a voltage feedback circuit for adjusting an output voltage of each power supply, and a controller for controlling the insulating device of each power supply and the voltage feedback circuit. Each of the power supplies further includes a current sensor for sensing a current at the output of each power supply, and each of the power supplies connected to the load via a respective isolation device such that output currents of all the power supplies are substantially equalized. And a current feedback circuit for adjusting an output current of the power supply. A redundant power supply system for supplying power to a load. 2. The system of claim 1, wherein all of the power supplies are connected together in parallel via a common current sharing bus. 3. Each of the voltage feedback circuits includes a local loop for feeding back a voltage at an upstream point of the isolation device of each power supply, and a remote loop for feeding back a voltage at a downstream point of the isolation device of each power supply. Wherein the controller selectively controls the local loop and the remote loop of each power supply, respectively, and selects a feedback voltage applied to each power supply. 3. The system of claim 2, wherein 4. A controllable isolator comprising: a plurality of power supplies having outputs connected in parallel to a load, each of the plurality of power supplies including a controllable isolation device for electrically connecting and disconnecting each power supply to and from the load. A voltage feedback circuit for adjusting the output voltage of each power supply, and a controller for controlling the insulation device and the voltage feedback circuit of each power supply, and a redundant power supply system for supplying power to a load. Each of the voltage feedback circuits includes a local loop for feeding back a voltage at an upstream point of the isolation device of each power supply, and a remote loop for feeding back a voltage at a downstream point of the isolation device of each power supply. And the controller selects the local loop and the remote loop of each power supply, respectively. A redundant power supply system for supplying power to a load, wherein the power supply is controlled in a controlled manner and a feedback voltage applied to each power supply is selected. 5. The controller of each power supply, wherein when the voltage at the upstream point is lower than the voltage at the downstream point, the voltage at the upstream point is fed back to the power supply; The local loop and the remote loop of each power supply are controlled so that the voltage at the downstream point is fed back to the power supply when the voltage at is lower than the voltage at the upstream point. System. 6. The system according to claim 5, wherein said local loop of each power supply includes an analog switch controlled by a controller of each power supply. 7. The system according to claim 5, wherein said local loop of each power supply includes an analog switch controlled by a controller of each power supply. 8. The remote loop of each power supply includes a resistor having a resistance substantially greater than a resistance of a local loop of the power supply when an analog switch in the local loop is closed. 7. The system of claim 6, wherein the loop is adapted to feed back voltage from the downstream point only when an analog switch in the local loop is closed. 9. The system according to claim 4, further comprising a common bus connecting remote loops of all power supplies in parallel at a point adjacent to the load. 10. Each of the power supplies further includes a current sensor that senses a current at the output of each power supply and an output current of all of the power supplies connected to the load via respective isolation devices. The system according to claim 4, further comprising a current feedback circuit for adjusting an output current of each power supply. 11. The system of claim 10, wherein all of the power supplies are connected together in parallel via a common current sharing bus. 12. The system according to claim 1, wherein the isolation device is a diode. 13. The system of claim 1, wherein said isolation device is a transistor.