JPH10234181A - Power supply unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve power efficiency and specify a failed machine by detecting abnormality, based on a self-current detection signal from the power supply voltage-generating part and a current balance signal detected by another power supply unit. SOLUTION: A self-current detection part 11, formed at a power supply voltage-generating part 10 detects self-current to output a self-current detection signal. A current balance signal drive part 20 outputs an additional current balance signal, based on the self-current detection signal and a current balance signal detected by another power supply unit. The additional current balance signal is compared with a reference value V1 by another power supply current discrimination part 21, and the self-current detection signal is compared with a reference value V2 by a self-current discrimination part 22. An alarm transmission part 23 outputs an alarm signal by receiving the output of the discrimination parts 21, 22. Therefore, if a self power supply unit becomes an abnormal low-voltage condition, the discrimination parts 21, 22 generate an active signal respectively, thus it is possible to detect abnormal low-voltage of the self power supply unit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply, and more particularly, to an alarm output circuit of a power supply configured to connect a plurality of power outputs in parallel to supply power to a load.

2. Description of the Related Art High reliability is required for a power supply device used in an information processing system or the like, and redundant operation is performed by connecting a plurality of power supplies in parallel. In such a power supply system, it is necessary that various alarms of each power supply device can be generated correctly.

[0003]

2. Description of the Related Art In a power supply unit operated in parallel redundant operation,
It is important to identify a faulty machine and maintain it within a specified time to improve reliability. As a method for that,
2. Description of the Related Art Conventionally, a technique is generally used in which each power supply device outputs its own output via a power diode, and an OR of these diodes is used to construct a redundant system.

FIG. 7 is a conceptual diagram of a conventional system. In the figure, reference numeral 1 denotes a power supply, and in the figure, N power supplies from the power supply 1 to the power supply N are shown. D is a power diode connected to the output of each power supply device, and these power diodes D are commonly connected on the cathode side. Reference numeral 2 denotes a load supplied with power from these diode common connection points.

In the power supply system having such a configuration, when one of them fails and becomes a low voltage, the diode D of the failed machine is reverse-biased. Can be easily performed.

[0006]

In the above-described conventional power supply system, a butt diode is connected in series to the output line of the power supply, so that a forward voltage drop occurs and the power conversion efficiency decreases. In addition, there is a problem that the cost of the power supply increases due to the cost of the diode, and the volume of the power supply increases due to the mounting space of the diode and its radiation fin.

If the butt diode is eliminated to improve power efficiency, even if one power supply unit fails,
Since the output voltage line is continuously supplied with the voltage from the remaining power supply device, it is not possible to detect a drop in the voltage, and there is a problem that a faulty device cannot be specified.

[0008] The present invention has been made in view of the above problems, and has as its object to provide a power supply device that can improve power efficiency and can identify a malfunctioning device.

[0009]

[Means for Solving the Problems]

(1) FIG. 1 is a principle block diagram of the present invention. The system shown in the figure constitutes a power supply device configured to receive an input voltage, convert the voltage to a different value, and operate in parallel with another power supply device.

In FIG. 1, reference numeral 10 denotes a power supply voltage generator for generating a power supply voltage, VIN + and VIN- designate voltage input terminals,
V + and V- are output voltage terminals. Reference numeral 11 denotes a self-current detector provided in the power supply voltage generator 10 for detecting a self-current.

Reference numeral 20 denotes a current balance signal drive unit for connecting the current value detected by the self-current detection unit 11 to another power supply device. Reference numeral CB denotes a current balance terminal interconnected between the power supply devices.

Reference numeral 21 denotes a first determination unit (other power supply current determination unit) for comparing a current balance signal from another power supply device with a first reference value V1, and 22 denotes an output of the self-current detection unit 11 and a second determination unit. A second determining unit (self-current determining unit) 23 for comparing the reference value V2 with the reference value V2 is an alarm transmitting unit that receives the outputs of the other power source current determining unit 21 and the self-current determining unit 22 and transmits an alarm signal. is there. ALM is an alarm terminal from which an alarm signal is output.

According to the configuration of the present invention, if the own power supply becomes abnormally low voltage, the low current is detected by the self-current detecting section 11 and the current balance signal from the other power supply increases. Therefore, both the other power supply current determination unit 21 and the self-current determination unit 22 can generate an active signal, and can detect a low voltage abnormality of the own power supply device.

Further, according to the configuration of the present invention, since the power supply output is directly connected without passing through the diode, it is possible to prevent a decrease in power conversion efficiency due to a forward voltage drop of the diode, and to eliminate the diode. Thus, the volume of the power supply device can be reduced. Therefore, according to the configuration of the present invention, the power efficiency can be improved, and the faulty machine can be specified.

(2) In this case, the first judging unit (other power source current judging unit) 21 outputs a detection signal indicating that the current balance signal is equal to or larger than the standard value by comparing with the predetermined value. The second determination unit (self-current determination unit) 22 outputs a detection signal indicating that the self-current detection signal is equal to or less than a standard value by comparing with the predetermined value,
It is characterized by comprising an alarm sending section 23 that receives detection signals from the first determination section and the second determination section and outputs an alarm signal.

According to the configuration of the present invention, if the self-power supply device does not have a low-voltage abnormality, the output of the self-current detection unit 11 has a normal value, so that the self-current judgment unit 22 does not become active. The alarm sending unit 23 can recognize that the own power supply device is not a low voltage abnormality. When both the output of the other power supply current judging section 21 and the output of the self-current judging section 22 are active, the alarm sending section 23 can send an alarm indicating that the self-power supply apparatus has a low voltage abnormality.

Therefore, the alarm sending section 23 uses the outputs of the other power supply current judging section 21 and the self-current judging section 22 to output
It is possible to recognize that the own power supply device has a low voltage abnormality.

(3) A delay unit for delaying the alarm signal output from the alarm sending unit for a predetermined time is provided. According to the configuration of the present invention, when an overvoltage abnormality occurs in any of the power supplies operating in parallel, the normal power supply outputs a low voltage abnormality,
By delaying this low voltage abnormality from the output of the overvoltage abnormality, it is possible to recognize that the alarm that occurs later is not an alarm indicating the abnormality. Can be specified.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 2 is a block diagram showing an embodiment of the present invention. The same thing as FIG.
The same reference numerals are given. In the figure, reference numeral 12 denotes a power conversion transformer (hereinafter simply referred to as a transformer) to which a primary-side DC voltage is applied, and 13 denotes a switching circuit connected in series with the primary side of the transformer 12 to turn on / off the DC voltage. . That is, the DC voltage is equal to the input terminal VIN + VIN−
Is applied to the series circuit of the primary side of the transformer 12 and the switching circuit 13.

The DC voltage is turned on / off by the switching circuit 13.
Upon the off-switching, a high-frequency AC voltage is generated on the secondary side of the transformer 12. Reference numeral 14 denotes a rectifying / smoothing unit that rectifies the AC voltage and converts the AC voltage into a flat DC. Reference numeral 11 denotes a self-current detecting unit that is connected in series to the secondary side of the transformer 12 and detects a self-current that flows through the secondary side. . V + and V− are terminals for taking out an output voltage from the rectifying / smoothing unit 14.

An output controller 15 detects the output voltage and controls the conduction time of the switching element in the switching circuit 13 (PWM control) so that the output voltage becomes constant. Then, the self-current detecting unit 11, the transformer 12,
The switching circuit 13, the rectifying / smoothing unit 14, and the output control unit 15 constitute the power supply voltage generating unit 10 in FIG.

Reference numeral 20 denotes a current balance signal drive unit for connecting the current value detected by the self-current detection unit 11 to another power supply device. Reference numeral CB denotes a current balance terminal interconnected between the power supply devices. The output of the current balance signal drive unit 20 is also provided to the output control unit 15. The current balance signal is proportional to the current value of the largest current machine that outputs the most current among the power supply devices that operate in parallel.

Reference numeral 21 denotes another power supply current judging section for comparing a current balance signal from another power supply with the first reference value V1,
Reference numeral 22 denotes an output of the self-current detection unit 11 and a second reference value V
The self-current judging section 23 for comparing the self-current judging section 2 with the other power source current judging section 21 and the self-current judging section 22 output an alarm signal.

As the first reference value V1, for example, about 30% of the rated current value is used, and as the second reference value V2, for example, about 10% of the rated current value is used.
The operation of the circuit thus configured will be described as follows.

During a normal operation, the switching circuit 13 receives a switching control signal from the output control unit 15.
Switches a DC voltage at a predetermined duty, and the high-frequency AC generated on the secondary side of the transformer 12 is rectified and smoothed by the rectifying and smoothing unit 14 to become a flat DC voltage, which is output from the output terminals V + and V-. . The output terminals V + and V- of these power supply devices are connected to each other and operated redundantly.
Power is supplied to a load (not shown).

It is assumed that a failure causing a low voltage abnormality has occurred in one of the power supply units that are operating in parallel and redundant manner. In this case, since the power supply line is not blocked by the butt diode, no droop of the output is seen in the power supply output of the faulty machine.

However, the output current of the faulty machine is almost zero.
, The output of the self-current detector 11 is small (the output is almost 0), and the second reference value V2
As compared with (for example, 10% of the rating), V2 is larger than the output of the self-current detection unit 11. Therefore, the output of the self-current judging unit 22 receiving these inputs becomes active (for example, “1”). As a result, it is detected that the output current of the own power supply device has been reduced for some reason.

However, this alone cannot determine whether the load current is actually small or whether the current is small due to the failure of the own power supply device. In this case, since the remaining power supply devices continue to supply power while sharing the current output from the failed device, the current balance signal from the power supply balance signal line is continued by another power supply device, The current balance signal increases.

The other power supply current judging section 21 calculates the first reference value V
1 (for example, 30% of the rating) and the current balance signal. Since the other normal power supply devices continue to operate by sharing the current of the failed power supply device, the current balance signal becomes larger than the first reference value V1, and the output of the other power supply current determination unit 21 becomes Become active.

The alarm sending section 23 receives the active signal of the other power supply current judging section 21 and the active signal of the self current judging section 22 and takes a logical product of them. Is output as an alarm signal.

According to this embodiment, since a butt diode is not used, power efficiency can be improved, and a faulty machine can be specified. Also, according to this embodiment, the alarm sending unit 23
However, upon receiving the active signal of the other power supply current judging unit 21 and the active signal of the self-current judging unit 22, the logical product of them is obtained, and an alarm indicating that the self-power supply device has a low voltage abnormality can be sent.

FIG. 3 is a circuit diagram showing a specific example of the configuration of the self-current detector 11. The same components as those in FIG. 2 are denoted by the same reference numerals. A current transformer CT is wound around a power supply line on the secondary side (output side) of the transformer 12.
A resistor R1 for current / voltage conversion is connected to both ends of CT to form a current loop. D1 is a rectifying diode that rectifies the high-frequency voltage generated at both ends of the resistor R1 and converts it into a DC voltage. A smoothing capacitor C1 is connected between the cathode side of the diode D1 and the common line. Then, the voltage applied to the capacitor C1 is output as a self-current detection signal. The operation of the circuit thus configured will be described as follows.

When the power supply is operating in a steady state, a high-frequency alternating current is generated on the secondary side of the transformer 12.
The high-frequency alternating current is rectified and smoothed by the rectifying and smoothing unit 14, and is taken out from the power supply terminals V + and V- as an output voltage. At this time, an alternating current flows through the output line. The CT detects an AC current corresponding to the flowing AC current. This AC current flows through the resistor R1 and is converted into an AC voltage.

The diode D1 rectifies this AC voltage and converts it to DC. The rectified DC is supplied to the capacitor C1.
And becomes a DC voltage having flat characteristics. The voltage applied to the capacitor C1 becomes the self-current detection signal.

According to this embodiment, since the CT detects the self-current flowing through the output side line in a non-contact manner, it is possible to surely detect the self-current without affecting the circuit.
FIG. 4 is a circuit diagram showing a specific configuration example of the current balance signal drive unit. In the figure, M1 is an amplifier that receives and amplifies the self-current detection signal detected by the self-current detection unit 11 and a current balance signal from the outside, and D2 is a diode that receives the output of the amplifier M1. This diode D2
Is provided to butt-connect (or connect) current balance signals from other power supply devices.

In the circuit thus configured, the control in the negative direction is prohibited by the diode D2, so that the current signal of the maximum current machine is constantly driven as the current balance signal. Therefore, the current balance signal matches the current balance signal of the power supply device that supplies the most output current.

According to this circuit, it is not necessary to disconnect the current balance signal drive unit 20 of the faulty machine from the current balance signal line, and the fault can be left unattended. FIG. 5 is a circuit diagram showing a specific configuration example of the alarm output unit. R2 to R4 are resistance voltage dividing resistors connected in series between the voltage Vcc and the ground GND. A voltage dividing circuit based on the voltage Vcc and these resistors constitutes a reference voltage generating circuit. The voltage Vcc is a voltage of a power supply provided separately for circuit operation.

From the connection point of the resistors R4 and R3, the rated 10
A reference voltage V2 for% determination is taken out, and resistors R3 and R2
A reference voltage V1 for judging 30% of the rated voltage is taken out from the connection point.

By configuring the reference voltage generating circuit with such a resistive voltage dividing circuit, the reference voltages V1 and V2 can be generated with a simple configuration. M2 is a comparator for comparing the reference voltage V1 for determining 30% of the rating with the current balance signal, and M3 is a reference voltage V2 for determining 10% of the rating.
And a comparator that compares the current with the self-current detection signal.
The comparators M2 and M3 are open collector output comparators whose outputs are connected to pull-up resistors R5 and R6.
Are commonly connected to the connection point. The comparator M2 forms the other power supply current determination unit 21, and the comparator M3 forms the self-current determination unit 22.

A resistor R is connected between the voltage Vcc and the ground GND.
5, a series circuit of R6 and a capacitor C2 is connected. The voltage at the connection point between the resistor R6 and the capacitor C2 is connected to the comparator M4. Comparator M
A reference voltage for comparison is input to the other input of the reference numeral 4. Then, the output of the comparator M4 becomes an alarm signal. The pull-up resistors R5 and R6, the capacitor C2, and the comparator M4 constitute an alarm sending unit 23. The resistors R5 and R6 and the capacitor C2 constitute an integration circuit (RC filter circuit). The operation of the circuit thus configured will be described as follows.

When the power supply device is operating normally, the self-current detection signal is higher than the rated reference voltage V2 for 10%, so that the output of the comparator M3 is at "0" level. In this case, since the outputs of the comparators M2 and M3 form a wired OR, the voltage of the common connection point becomes the "0" level regardless of the output of the comparator M2. Since the output of the integrating circuit is smaller than the reference voltage of the comparator M4, the output of the comparator M4 becomes "0" level and no alarm signal is output.

On the other hand, when the power supply becomes abnormally low voltage, the self-current detection signal becomes lower than the rated 10% reference voltage V2, and the output of the comparator M3 becomes "1" level. On the other hand, since the current balance signal of the other power supply device input to the comparator M2 is higher than the rated reference voltage V1 for 30%, the output of the comparator becomes "1" level. Therefore, the voltage at the connection point between the resistors R5 and R6 is "1".
Level.

The comparator M4 compares the output of the integrating circuit (the voltage applied to the capacitor C2) with the reference voltage.
Since the output of the integrator circuit is higher than the reference voltage, the output becomes "1" level, the alarm signal becomes "1", and becomes active. As a result, it is possible to detect that the own power supply device has a low voltage abnormality.

FIG. 6 is a block diagram showing another embodiment of the present invention. The same components as those in FIG. 2 are denoted by the same reference numerals. This embodiment is different from the first embodiment in that a delay circuit 24 is provided at the output unit of the alarm sending unit 23. Other configurations are exactly the same as those in FIG. The operation of the device configured as described above will be described below.

In the case of the low voltage failure determination method shown in FIG.
When an overvoltage fault occurs, an alarm may be detected from devices other than the failed device. This is because when an overvoltage occurs and the output voltage of the faulty machine gradually increases, the voltage of the normal machine gradually increases due to the function of the current balance function.

However, when the output voltage of the faulty machine rises beyond the range of the current balance circuit, thereafter, only the overvoltage faulty machine shares all the load current, and the output of the normal machine becomes zero. It is because. At this time, the condition for judging a low voltage abnormality by the low voltage failure judgment method of the present invention is satisfied.

That is, it is assumed that the power supply device shown in FIG. 6 is a normal device. When the other power supply device becomes overvoltage abnormal, the output voltage of the power supply unit becomes 0, the output of the self-current detection unit 11 decreases, the output of the self-current determination unit 22 becomes active,
It becomes “1” level. In addition, the current balance signal from the other power supply device (overvoltage fault device) becomes larger than the reference value V1, the output of the other power supply current determination unit 21 becomes active, and becomes "1" level.

Therefore, as a result of the outputs of the other power supply current judging section 21 and the self-current judging section 22 both at the "1" level, the alarm sending section 23 outputs an alarm signal indicating a low voltage abnormality.

The alarm signal is output after being delayed by, for example, about one second by the delay circuit 24. On the other hand, since an overvoltage abnormality alarm is generated from the overvoltage abnormality machine, the low voltage abnormality alarm that occurs after the overvoltage alarm can be determined to be a low voltage abnormality alarm that has occurred due to the overvoltage abnormality. . That is, a faulty machine can be specified based on the order in which the alarm signals are received.

When the output voltage rises and becomes overvoltage faster than the alarm signal transmission delay time, when the faulty device sends out an overvoltage alarm and stops the output, the normal device has not yet sent out the alarm. Since the output current flows again from the normal machine, no alarm signal is output from the normal machine and continuous operation is possible.

According to this embodiment, when the power supply has an overvoltage abnormality, the power supply having the overvoltage abnormality can be specified by the order of sending the alarm. In the above-described embodiment, the case where a DC / DC converter type is used as the power supply voltage generation unit 10 is taken as an example, but the present invention is not limited to this, and other types of power supply voltage generation systems For example, the present invention can be similarly applied to a power supply of a series control system and the like.

[0052]

As described above in detail, according to the present invention, there are provided: (1) a power supply voltage generator for generating a power supply voltage, and a self-current detection by detecting a self-current from the power supply voltage generator. A self-current detection unit for outputting a signal, and a new current based on a self-current detection signal output by the self-current detection unit and a current balance signal output based on a self-current detected by another power supply device. A current balance signal driver for outputting a balance signal; a first determination unit for comparing the current balance signal output from the current balance signal driver with a predetermined value; and a self-current detection output from the self-current detector. Since the power supply output is directly connected without passing through the diode by providing the second determination unit that compares the signal with a predetermined value, the power conversion efficiency is reduced due to the forward voltage drop of the diode. Since the lowering can be prevented and the diode is eliminated, the volume of the power supply device can be reduced, so that the power efficiency can be improved and the malfunctioning device can be identified.

(2) In this case, the first judging section outputs a detection signal indicating that the current balance signal is equal to or larger than the standard value by comparing with the predetermined value, and the second judging section outputs A detection signal indicating that the self-current detection signal is equal to or smaller than a standard value is output by comparison with the predetermined value, and an alarm signal is output in response to the detection signals from the first determination unit and the second determination unit. When the output of the other power supply current judging unit and the output of the self-current judging unit are both active, the alarm sending unit can send an alarm indicating that the self-power supply device has a low voltage abnormality. .

(3) By providing a delay unit for delaying the alarm signal output from the alarm sending unit for a certain period of time, when the power supply has an overvoltage abnormality, the power supply having the overvoltage abnormality can be specified. .

[Brief description of the drawings]

FIG. 1 is a principle block diagram of the present invention.

FIG. 2 is a block diagram showing an embodiment of the present invention.

FIG. 3 is a circuit diagram showing a specific configuration example of a self-current detection unit.

FIG. 4 is a circuit diagram showing a specific configuration example of a current balance signal driving unit.

FIG. 5 is a circuit diagram showing a specific configuration example of an alarm output unit.

FIG. 6 is a block diagram showing another embodiment of the present invention.

FIG. 7 is a conceptual diagram of a conventional system.

[Explanation of symbols]

 Reference Signs List 10 power supply voltage generator 11 self-current detector 20 current balance signal driver 21 first determination unit (other power supply current determination unit) 22 second determination unit (self-current determination unit) 23 alarm transmission unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tetsuhiko Ichihashi 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Within Fujitsu Limited (72) Inventor Kazuya Okamoto 4-chome, Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa No. 1 Fujitsu Limited (72) Inventor Hironobu Kageyama 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Within Fujitsu Limited (72) Inventor Keiya Suzuki Uno-cho, Unoki-cho, Kawakita-gun, Ishikawa Prefecture 98 kinu 2 inside PFU Co., Ltd.

Claims (3)

[Claims] A power supply voltage generator for generating a power supply voltage; a self current detector for detecting a self current from the power supply voltage generator and outputting a self current detection signal; A current balance signal driver that outputs a new current balance signal based on the self-current detection signal that has been output and a current balance signal that is output based on a self-current detected by another power supply device; and the current balance signal driver. A first determination unit that compares the current balance signal output from the self-current detection signal with a predetermined value; and a second determination unit that compares the self-current detection signal output from the self-current detection unit with a predetermined value. And power supply. 2. The method according to claim 1, wherein the first determination unit outputs a detection signal indicating that the current balance signal is equal to or more than a standard value by comparing the current balance signal with the predetermined value. An alarm sending unit that outputs a detection signal indicating that the self-current detection signal is equal to or smaller than a standard value by comparison, and outputs an alarm signal in response to the detection signals from the first determination unit and the second determination unit. The power supply device according to claim 1, further comprising: 3. The power supply device according to claim 2, further comprising a delay unit that delays the alarm signal output from the alarm transmission unit for a predetermined time.