JPH0746837A - Switching power supply - Google Patents

Abstract

PURPOSE:To increase reliability without providing a spare power supply outside, by a construction wherein a plurality of voltage converters are connected in parallel and each control command is transmitted to other voltage converters in common, while an internal output voltage of each voltage converter is monitored and the existence or nonexistence of a failure is informed to the outside. CONSTITUTION:A switching power supply 1 is constructed by connecting a plurality of DC-DC converters 2 in parallel. In the case when an output voltage fluctuates herein, a comparator part 23 of each DC-DC voltage converter 2 transmits a control voltage signal 24 to output voltage control parts 25 of the other DC-DC converters 2 through a transmission line 4 and the switching power source 1 as a whole outputs a prescribed output voltage by coordinated operations. In the case of a short-circuit accident, a fuse 3 is blown out and the failing DC-DC converter 2 is cut off. Moreover, a failure detecting circuit 5 monitors a state of operation of each DC-DC converter 2 on the basis of DC voltage signal 26 and delivers a maintenance request signal outside when it detects the failure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching power supply device, and more particularly to a super-large computer, a server system, etc.
The present invention relates to a switching power supply device used as a power supply for equipment that requires extremely high reliability.

[0002]

2. Description of the Related Art Conventionally, a switching power supply device requires a large number of parts in principle, and its reliability cannot be said to be sufficient. In particular, it is problematic from the viewpoint of reliability to directly apply it to a power supply that requires an extremely large capacity output, such as for a super-large computer, or a power supply of a server system in which system down is not allowed.

In order to solve this, a method is known in which a plurality of switching power supply devices are connected in parallel to perform a redundant operation ("parallel operation of large capacity switching power supply" Fuji Denso Co., Ltd., 1988). May 2nd, (88) Switching Power Supply Symposium, sponsored by Japan Management Association. This report discloses a technique of performing redundant operation by so-called plural switching power supply devices, in which power is supplied by (N + K) switching power supply devices to a load having a capacity that can be output by N switching power supply devices. Has been done.

[0004]

However, in the above-mentioned conventional technique, although reliability can be improved, a spare switching power supply device must be provided outside in order to perform redundant operation, and the size of the power supply unit is large. Becomes larger,
There is a problem that extra cost is required.

An object of the present invention is to provide a switching power supply device which is small in size and cost and has high reliability without providing an external switching power supply device.

[0006]

In order to achieve the above object, the present invention compares its own output voltage with a predetermined reference voltage, and outputs an up / down control command for its own output voltage according to the comparison result. A plurality of voltages, each of which is connected in parallel in one power supply device, are provided with comparing means for outputting and output voltage controlling means for controlling its own output voltage in accordance with the up / down control command output from the comparing means. A converter, a transmission unit that commonly transmits the vertical control command to the vertical control command output unit of another voltage converter, and a notification unit that monitors the internal output voltage of each voltage converter to detect the presence or absence of a failure and notify the outside. And have.

[0007]

According to the above means, each voltage converter evenly shares and outputs the load voltage (current). However, when any one of the voltage converters fails and the output voltage drops below the rated output voltage, the control means for increasing the output voltage is output from the comparing means of the voltage converter.

This up / down control command is input to its own output control means and acts so as to raise its own output voltage. However, its own output voltage does not rise because some failure has occurred.

On the other hand, however, the up / down control command is also input to the output voltage control means of another voltage converter via the transmission means.

As a result, the other voltage converter raises the output voltage. Then, when the output voltage at the common connection point of each voltage converter becomes equal to or higher than the reference voltage of the comparison means that has issued the vertical control command, the output of the vertical control command is stopped.

That is, the output voltage (current) is maintained at a predetermined value by the cooperative operation of the voltage converters that have not failed.

[0012]

Embodiments of the present invention will now be described in detail with reference to the drawings. In all the drawings for explaining the embodiments, parts having the same functions are designated by the same reference numerals, and repeated description thereof will be omitted.

(Embodiment 1) FIG. 1 is a block configuration diagram of a switching power supply device constructed by connecting eight DC-DC converters in parallel and an internal block configuration diagram of the DC-DC converter.

In FIG. 1A, 1 is a power supply unit, and 2 is a DC-DC converter that outputs a predetermined DC voltage / current based on the input DC voltage / current.

Reference numeral 3 is a fuse for blowing the DC-DC converter 2 when the DC-DC converter 2 fails (particularly when a large current flows to the input due to an output short circuit) and disconnects the failed DC-DC converter 2 from the parallel connection state. 4 is each DC
-Transmission lines 5 for mutually transmitting the control voltage signals of the DC converter are failure detection circuits.

The specifications of the switching power supply device in this configuration are that the input voltage is 260 VDC and the output capacity is 3V50.
It is 0A.

FIG. 1B is a block diagram showing the internal structure of one DC-DC converter 2.

In FIG. 1B, reference numeral 21 is an inverter section for switching a DC input voltage to convert it into a pulse voltage, 22 is a rectification / smoothing section for rectifying / smoothing the pulse voltage output from the inverter section 21, Reference numeral 23 is a comparison unit that detects the output voltage and compares it with a reference voltage, 24 is a control voltage signal generated by the comparison unit 23, and 25 is a control voltage signal 2
4, an output voltage control unit that controls the switching frequency in the inverter unit 21 and adjusts the output voltage.
Reference numeral 6 is a DC voltage signal for monitoring the internal output voltage of each DC-DC converter 2 and detecting a failure.

The output voltage control section 25 controls the switching frequency of the inverter section 21 in accordance with the voltage level of the control voltage signal 24 generated by the comparison section 23, and outputs its own DC voltage.
-Increase or decrease the output voltage of the DC converter 2,
Adjust the output voltage.

Further, if the output voltage (current) is lowered due to a failure or the like, the comparison section 23 will change to another DC-DC.
The control voltage signal 24 is transmitted to the output voltage control unit 25 of the converter 2 via the transmission line 4, and the other DC-DC converters 2 output the output voltage and current which the faulty DC-DC converter 2 is responsible for. Make up for.

That is, another DC-DC that has not failed
By the converter 2 performing the cooperative operation, the switching power supply device as a whole maintains a predetermined output voltage and current.

In FIG. 1 (A), each DC-DC converter 2 is designed to have a maximum current output capacity of 72 A, but normally one unit outputs 63 A, and a total current of 500 A is output. To do.

This is due to the transmission line 4 of each DC-D.
The control voltage signal 24 output from the comparison unit 23 of the C converter 2 is commonly transmitted to all the output voltage control units 25, so that the output commanded by the common control voltage signal 24 in each DC-DC converter 2 is output. This is because it operates so that it becomes a voltage.

For example, one of the DC-DC converters 2 with 500 A output as the power supply unit 1
When an individual piece fails, the voltage level of the control voltage signal 24 of the failed DC-DC converter 2 decreases. Then, the decrease in the voltage level of the control voltage signal 24 is caused by other 7
The output currents are transmitted to the individual DC-DC converters 2, and their output currents are increased from 63 A to 72 A per unit, and the power supply unit 1 as a whole maintains an output current of 500 A and operates to supply this.

The failure mode of the DC-DC converter 2 is mainly divided into a short circuit and a disconnection. When a large current flows through the input due to the short circuit, the fuse 3 is blown and the DC-DC converter 2 fails. Is disconnected from the parallel connection state of.

Further, the failure detection circuit 5 constantly monitors the operating state of each DC-DC converter 2 by the DC voltage signal 26, and when any failure of the DC-DC converter 2 is detected, it is notified to the outside. Request maintenance. As a result, maintenance work is immediately performed.

FIG. 2 is a circuit diagram showing details of the internal configuration of the power supply unit 1. In FIG. 2, the power supply unit 1
Are eight constant current output type DC-DC converters 2, 8
The fuse 3 and the failure detection circuit 5 are connected to each other, and a portion for controlling the output voltage of each DC-DC converter 2 is connected by a transmission line 24. With this configuration, the input voltage is 260VDC and the output capacity is 3V.
It is 500A.

The constant current output type DC-DC converter 2 operates to change the output voltage so that a constant current always flows through the load connected to the output terminal.

In FIG. 2, the input voltage that has passed through the fuse 3 is switched by the transistor 201, becomes a pulse voltage, and is applied to the transformer 202.
The pulse voltage transformed by the transformer 202 is rectified by the diode 203, smoothed by the diode 204, the choke coil 205, and the capacitor 206, and becomes an output voltage.

The circuit composed of the diode 208, the capacitor 209 and the resistor 210 constitutes a reset circuit for resetting the magnetic flux accumulated in the transformer 202 while the transistor 201 is in the ON state.

The pulse current flowing through the transistor 201 is converted into a pulse voltage by the current transformer 207 and the resistor 211, rectified by the diode 212, smoothed by the capacitor 213 and becomes a DC voltage proportional to the pulse current value.

This DC voltage is applied to the (+) terminal of the amplifier 214 and is compared with the voltage level of the transmission line 4 which is also applied to the (−) terminal of the amplifier 214, and the difference is amplified and the comparator 215. Applied to the (+) terminal of.

The comparator 215 compares this amplified difference with the triangular wave output from the oscillator 218 which is also applied to the (-) terminal of the comparator 215 and converts it into a square wave. This square wave is amplified by the driver 216 and controls the on / off of the transistor 201 via the drive transformer 217.

The ON pulse width of the transistor 201 is inversely proportional to the voltage level of the control voltage signal 24, and as a result, each DC-DC connected by the transmission line 4 is connected.
The constant-current output type DC-DC converter 2 is controlled by the voltage level of the control voltage signal 24 of the converter.

The output voltage is divided by the resistors 219 and 220, compared with the reference voltage 222 by the amplifier 221, and the difference is amplified and passed through the diode 223 to the DC-DC converters 2 as the control voltage signal 24. It is transmitted via the transmission line 4. The resistor 224 sets the voltage level of the control voltage signal 24.

Next, the principle of operation of this circuit as a constant voltage power source will be described by taking one circuit of the DC-DC converter 2 as an example.

In FIG. 2, first, the output voltage is zero in the initial state, and the voltage at the (−) terminal of the amplifier 221 is also zero. Therefore, the output of the amplifier 221 is high level, and the voltage level of the control voltage signal 24 is also high level.

At this time, since no current has flown in the transistor 201, the output of the amplifier 214 becomes low level, and the ON width of the output pulse of the comparator 215 becomes maximum.

Therefore, the transistor 201 starts switching with the maximum pulse width. As a result, the output voltage rises, a current flows through the transistor 201, and when the voltage at the (+) terminal of the amplifier 214 matches the voltage value of the control voltage signal 24, balance is established and the current source becomes a constant current source.

However, in this state, the output voltage tries to rise to the outputtable voltage of the circuit, but the resistors 219, 2
When the voltage value determined by 20 and the reference voltage 222 is reached, the output of the amplifier 221 becomes low level, and the voltage level of the control voltage signal 24 also becomes low level to establish balance.

After that, the voltage level of the control voltage signal 24 continues to operate in a state where the output current is controlled by the output voltage, and as a result, it operates as a constant voltage power supply.

Next, the operating principle of parallel operation will be described with reference to FIG. In Figure 2, eight DC
The (−) terminals of the amplifier 214 of the −DC converter 2 are connected to each other by the transmission line 4. Therefore, as described above, all the DC-DC converters 2 operate so that the voltage values become equal to each other, and the voltage is automatically balanced.

Voltage stabilization at this time is performed by each DC-
This is performed by the eight amplifiers 221 in the DC converter 2, but the amplifier 221 in the DC-DC converter 2 that is set to invert at the lowest voltage in the circuit becomes the center of operation, and the other amplifiers 221 It is in a cutoff state.

Next, the operating principle of redundant operation will be described. In FIG. 2, if any of the eight DC-DC converters 2 is short-circuited due to a failure, an excessive current flows and the fuse 3 is blown.

Therefore, the eight DC-DC converters 2
One of them stops its operation, the output current drops to 7/8, and the output voltage drops accordingly.

Then, the output of the amplifier 221 becomes high level, and the voltage level of the control voltage signal 24 also becomes high level. As a result, as described above, the on-pulse width of the transistor 201 is finally expanded, and as a result, the output voltage (current) returns to the original state.

Since this series of operations is instantaneously performed, the output voltage (current) does not fluctuate. The same applies to the case where the transistor 201 is disconnected.

When the output voltage of the transformer 202 is rectified by the diode 225 and smoothed by the capacitor 226,
A DC voltage signal 26 indicating that the DC-DC converter 2 is operating is obtained. Even if this is monitored at the output terminal, current will flow from another DC-DC converter 2, and accurate information cannot be obtained.

Therefore, when the DC voltage signals 26 of the respective DC-DC converters 2 are collected and processed by the failure detection circuit 5 composed of AND circuits, if any one of them is missing,
Since the AND circuit is not established, the maintenance request signal can be output when any of the eight DC-DC converters 2 fails.

(Embodiment 2) FIG. 3 is a block diagram of a switching power supply device constituted by connecting eight AC-DC converters 6 in parallel. As a specification, the input voltage is 20
It has 0 VAC and an output capacity of 3 V 500 A.

In FIG. 3, the AC-DC converters 6 are designed to have a current output capacity of 72 A, respectively.
Outputs 63A per unit, 500A as a whole
It has a current output capacity of.

In FIG. 3, the output voltage of each AC-DC converter 6 is compared by the control voltage signal 24 transmitted through the transmission line 4, and the output voltage control section 25 of each AC-DC converter 6 is The output currents of the remaining AC-DC converters 6 are reduced to 1 when the output is stopped due to a failure or the like of any of the eight AC-DC converters 6 while operating so as to match them. Increase from 63A to 72A per piece, 500A as a whole
The current output capacity of can be maintained and supplied.

The failure mode of the AC-DC converter 6 is
It is mainly divided into short circuit and disconnection, but when a large current flows to the input due to the short circuit, the fuse 3 is blown and the AC
-The DC converter 6 is disconnected from the parallel connection state.

The failure detection circuit 5 monitors the operating state of each AC-DC converter 6 by the DC voltage signal 26, and when any failure of the AC-DC converter 6 is detected, it is notified to the outside. Request maintenance. As a result, maintenance work is immediately performed.

(Embodiment 3) FIG. 4 is a diagram showing an embodiment in which four switching power supply devices described in FIG. 1 are connected in parallel to increase the output capacity. As specifications, the input voltage is 260 VDC and the output capacity is 3 V 2000 A.

The power supply unit 1 is the DC-D described in FIG.
Eight C converters 2 are built in each, and a total of 32 DC-DC converters 2 operate in parallel in the configuration of FIG.

In the unlikely event that the output voltage (current) drops due to a failure or the like, the comparison section 23 sends a control voltage signal 24 to the output voltage control section 25 of another DC-DC converter 2.
Is transmitted via the transmission line 4, and the other DC-DC converter 2 supplements the output voltage and current which the defective DC-DC converter 2 is responsible for.

This is due to the transmission line 4 of each DC-D.
The control voltage signal 24 output from the comparison unit 23 of the C converter 2 is commonly transmitted to all the output voltage control units 25, so that the output commanded by the common control voltage signal 24 in each DC-DC converter 2 is output. This is because it operates so that it becomes a voltage.

For example, when one of the DC-DC converters 2 fails in the state where the four power supply units 1 are outputting 2000A as a whole, the output of the remaining 31 DC-DC converters 2 63A per current
To 72 A, maintaining an output current of 2000 A overall and operating to supply this.

Each of the power supply units 1 incorporates the failure detection circuit 5 described with reference to FIG. 1, and has 32 DC-Ds.
When any failure of the C converter 2 is detected, it notifies the outside and requests maintenance. As a result, maintenance work is immediately performed.

From the above, the DC-DC converter 2 3
Since the parallel operation is performed by the two power supply devices, a switching power supply device having a large current capacity can be realized.

Even if one of the 32 DC-DC converters 2 fails, the remaining DC-DC converters 2 maintain the predetermined output voltage and current. .

(Embodiment 4) FIG. 5 shows one DC-DC converter 2 described in FIG. 1 and FIG. FIG. 3 is a block configuration diagram when shared by converters 2. As a specification, the input voltage is 260V, similar to FIG. 1 and FIG.
DC, output capacity is 3V500A.

In FIG. 5, the power supply unit 1 is composed of eight DC / DC converters 2 of constant current output type, a fuse 3, a transmission line 4, a failure detection circuit 5, and one comparison section 23.

In FIG. 5, since there is only one comparison unit 23, the failure of this comparison unit 23 cannot be saved. However, in general, when the comparison unit 23 is viewed from the entire DC-DC converter 2,
It is possible to configure with an overwhelmingly small number of parts, and by forming the comparison unit 23 into an integrated circuit, the reliability can be improved to a level where there is no practical problem.

In this embodiment, the comparison unit 23 is set to DC-
Although the example provided outside the DC converter 2 has been described, the comparison unit 23 in one DC-DC converter 2 may be shared by the other seven DC-DC converters 2.

This eliminates the need for the comparators 23 in the other seven DC-DC converters 2, thus reducing the size and cost of the power supply unit 1.

Since the number of parts is greatly reduced,
The probability of failure will decrease accordingly.

(Embodiment 5) However, if the reliability is still uncertain, a plurality of comparators 23 are provided (two in parallel in this embodiment) as shown in FIG.
By performing a cooperative operation like the C converter 2,
It is also possible to increase reliability.

According to the above embodiment, it is possible to reduce the size and cost of the switching power supply device without providing a spare power supply unit for performing redundant operation outside.

In the above embodiment, the power supply unit 1
In the above description, the eight DC-DC converters 2 or the AC-DC converters 6 are connected in parallel, but other combinations may be used.

In the third embodiment, the power supply unit 1 is replaced by 4
An example in which the units are connected in parallel has been described, but other combinations of configurations may be used.

Further, the failed DC-DC converter 2
Alternatively, the fuse 3 used for disconnecting the AC-DC converter 6 can be configured by other means such as a circuit breaker, a relay, and another electronic circuit.

FIG. 7 is a diagram for explaining a volume comparison when a power supply unit for a large-sized computer (20 kinds of output voltage, 40 KW in total) is realized by the switching power supply device of the prior art and the switching power supply device according to the present invention. It is a figure.

In FIG. 7, 71 is each part of the switching power supply device, 72 is a unit volume of each part,
73 is the number of parts used in each part of the switching power supply according to the present invention, 74 is its volume, 75 is the number of parts used in each part of the conventional switching power supply, and 76 is its volume.

As is clear from FIG. 7, the number of used DC-DC converters 2 is 69 in the prior art, and the number 73 used in the present invention is 49.

The total volume is the same as that of the prior art volume 76.
Is 89ν, and the volume 74 according to the present invention is 69ν, and it is possible to reduce the number of uses by 20 and the volume by 23%, respectively.

[0078]

As described above, according to the present invention,
Comparison means for comparing its own output voltage with a predetermined reference voltage, and outputting a vertical control command for its own output voltage according to the comparison result, and its own output voltage according to the vertical control command output from this comparing means. And a plurality of voltage converters each of which outputs are connected in parallel in one power supply device, and the up / down control command is commonly output to the up / down control command output unit of another voltage converter. Since there is a transmitting means for transmitting and a notifying means for monitoring the internal output voltage of each voltage converter to detect the presence or absence of a failure and notifying it to the outside, conventionally, a plurality of switching power supplies are connected in parallel to perform a redundant operation. The same effect as when
This can be realized by a single switching power supply device, and the size and cost of the power supply unit of various devices can be reduced.

Further, even if any one of the plurality of voltage converters fails, the output capacity of the switching power supply device as a whole is maintained and the presence or absence of the failure of the voltage converter is notified by the notification means. There is an effect that repair or replacement work of a faulty voltage converter can be performed while the power supply is operating.

When the comparison means of one voltage converter is shared by another voltage converter, not only the size and cost of the switching power supply device can be reduced, but also the number of parts constituting the voltage converter is significantly increased. Therefore, the effect that the probability of failure also decreases can be expected.

Further, when the comparison means common to the voltage converters is provided in place of the comparison means of each voltage converter and the output voltage control means of each voltage converter is controlled by this common comparison means, the switching power supply device The size and cost can be reduced.

Further, the common comparing means is at least two.
In the case where two comparing units are provided in parallel, the comparing unit also operates in the same manner as the DC-DC converter, and even if one of the comparing units fails, the reliability of the switching power supply device can be improved by the remaining comparing units. Can be kept.

From the above, it is possible to realize a rational and highly reliable switching power supply unit in terms of both size and cost, and to supply a power supply for a super large-scale computer or a device requiring extremely high reliability. Can be used for

[Brief description of drawings]

FIG. 1 is a first embodiment of a switching power supply device according to the present invention.
It is a block configuration diagram of.

FIG. 2 is a circuit diagram showing details of the internal configuration of the power supply unit according to the first embodiment.

FIG. 3 is a second embodiment of the switching power supply device according to the present invention.
It is a block configuration diagram of.

FIG. 4 is a third embodiment of the switching power supply device according to the present invention.
It is a block configuration diagram of.

FIG. 5 is a fourth embodiment of the switching power supply device according to the present invention.
It is a block configuration diagram of.

FIG. 6 is a fifth embodiment of the switching power supply device according to the present invention.
It is a block configuration diagram of.

FIG. 7 is a diagram for explaining a comparison between the switching power supply device according to the present invention and a conventional technique.

[Explanation of symbols]

1, ... Power supply unit, 2 ... DC-DC converter, 3 ...
Fuse, 4 ... Transmission line, 5 ... Failure detection circuit, 6 ... AC-
DC converter, 21 ... Inverter section, 22 ... Rectification / smoothing section, 23 ... Comparison section, 24 ... Control voltage signal, 25 ... Output voltage control section, 26 ... DC voltage signal.

Continuation of the front page (72) Inventor Kiichi Tokunaga 4026 Kuji-cho, Hitachi City, Ibaraki Prefecture Hitachi Research Laboratory, Hitachi, Ltd.

Claims (6)

[Claims] 1. A comparison means for comparing its own output voltage with a predetermined reference voltage and outputting a vertical control command for its own output voltage according to the comparison result, and a vertical control command output from this comparing means. Output voltage control means for controlling its own output voltage in accordance with the above, each output having a plurality of voltage converters connected in parallel in one power supply device, and the vertical control command of the other voltage converter A switching power supply device comprising: a transmission unit that commonly transmits to the output unit; and a notification unit that monitors the internal output voltage of each voltage converter to detect the presence or absence of a failure and notify the outside. 2. The voltage converter is a constant current output type DC-DC converter.
The switching power supply described. 3. The voltage converter is a constant current output type AC-DC converter.
The switching power supply described. 4. The switching power supply device according to claim 1, wherein the comparison means of one voltage converter is shared by another voltage converter. 5. A comparison means common to each voltage converter is provided in place of the comparison means of each voltage converter, and the output voltage control means of each voltage converter is controlled by this common comparison means. 4. The switching power supply device according to any one of 3 to 3. 6. The switching power supply device according to claim 5, wherein at least two common comparing means are provided in parallel.