JP3534109B2 - POWER SUPPLY DEVICE AND POWER SUPPLY SYSTEM USING THE SAME - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an AC-DC converter, a DC-DC converter, and other power supply devices that supply stable DC power to a load, and a power supply system in which the power supply devices are connected in parallel as a unit.

[0002]

2. Description of the Related Art Conventionally, regarding a power supply device such as an AC-DC or a DC-DC converter, in order to keep the output voltage constant, generally, the output voltage is detected and fed back to the main circuit of the power supply device for control. Voltage feedback control is widely used. Here, the main circuit means a circuit having a function of converting AC or DC input power into predetermined DC power (regardless of accuracy). The accuracy does not matter means that the power supply output is not stabilized or the stabilization is not sufficient. Japanese Patent Laid-Open No. 58-198122 discloses a configuration of power supply devices connected in parallel by using this voltage feedback control (FIG. 12). Power supply A in FIG.
, 26 is a switching circuit, 27 is a transformer,
28 is a rectifying / smoothing circuit, 29 is a drive circuit, 30 is a comparator,
31 is an error amplifier, 32 is an oscillator, and 33 is a triangular wave generator. A plurality of power supplies (A, B, ...) Having the same configuration respectively connect the output side of the power supplies by a diode 51 in a wired OR logic in parallel to a common circuit to supply power to a load. It is possible to allow the load to flow up to the total current of the outputs of all the power supplies.

The circuit operation of FIG. 12 will be described. When an unstabilized DC voltage is input, it is converted into desired DC power via the internal switching circuit 26, transformer 27, and rectifying / smoothing circuit 28. The output voltage applied to the load via the diode 51 is input to the non-inverting input terminal of the error amplifier 31. The reference voltage Vref for setting the output voltage is input to the inverting input terminal of the error amplifier 31.

The error amplifier 31 compares the error signal obtained by comparing and amplifying the output voltage and the reference voltage with each other, and outputs the error signal to the comparator 30.
To one of the inputs. The triangular wave pulse sent from the triangular wave generator 33 in synchronization with the output of the oscillator 32 is input to the other input terminal of the comparator 30.

A pulse signal whose time width changes in accordance with the error signal output from the error amplifier 31 is output to the output terminal of the comparator 30. This pulse signal is applied to the drive circuit 2
It is fed back to the switching circuit 26 via 9, and the output voltage of the power supply device is controlled so that the load voltage always becomes a constant value.

In the power supply device having this circuit configuration, even if the output voltage is reduced due to a failure of some of the power supply units during parallel operation, if the power supply device with reduced output is in the redundant range, Wired or connected diode 5
By 1, the output of the failed power supply device is automatically cut off, so that power is continuously supplied to the load by each of the remaining power supply devices.

In an electronic system requiring a high reliability of a power supply, for example, a RAID type magnetic disk storage device, in order to improve the system reliability, the power supply device is provided with a parallel redundant operation function of the power supply unit and an automatic failure power supply. It is required to have a disconnection function, a hot-swap maintenance function for the power supply device, and the like. In terms of the circuit, it is necessary to reduce the short-circuit element of the power supply output and to eliminate the power supply failure potential that causes a power failure (system down) of the entire electronic system.

In the prior art, the terminals to which the output was applied to the load were monitored. Therefore, when the forward voltage of the diode connected in the wired OR changes with the change of the load current, the power supply device feeds back the change of the output voltage to the main circuit and controls the output voltage to be always constant.
However, in the parallel power supply system having this circuit configuration, if even one of the power supply units connected in parallel short-circuits the voltage detection line for voltage feedback, all of the other power supply devices connected in parallel are short-circuited. Is equivalent to, and the whole parallel power supply system goes down. In other words, it did not follow the wired or logic.

[0009]

Such a conventional parallel power supply system has a fatal problem from the viewpoint of high reliability.
It cannot be used for electronic systems that require high reliability. Therefore, the voltage detection line required for voltage feedback control is
The output diode is connected to the anode side (the power supply side, not the load side) (FIG. 1). As a result, when the voltage sense line of the power supply is short-circuited, the overcurrent protection circuit operates in the power supply unit having a short-circuited terminal (hereinafter referred to as a failed power supply unit) to cut off the output power. As a result, the output voltage from the other power supply unit is applied to the terminal of the faulty power supply unit, but the faulty power supply unit is connected to the diode output terminal that is the backflow limiting element, and the internal terminal The internal resistance is increased to allow for this. Therefore, by limiting the inflow of electric power from other power supply units, only the faulty power supply unit is separated from the parallel power supply system.

However, in the circuit configuration of FIG. 1, the target of the voltage feedback control is the anode side of the output diode. Therefore, when the load current increases, the output voltage of the power supply device decreases due to the change in the forward voltage drop of the output diode. . That is, in this configuration, the regulation characteristic of the output voltage is not good with respect to the variation of the load current. Fluctuations in the output voltage of the power supply device reduce the operating margin of the load to which the voltage is supplied, which is not preferable.

The object of the present invention is to eliminate the obstacle element due to the output short circuit of the power supply device and to be suitable for a high reliability system.
It is an object of the present invention to provide a power supply device having a circuit configuration shown in FIG. 1 which corrects a voltage drop of an output voltage caused by a voltage drop element such as a diode in an output stage and has a good output voltage regulation characteristic. Another object of the present invention is to provide a power supply device in which the correction control of the voltage drop operates stably even in parallel redundant operation of the power supply device (unit).

Other objects of the present invention will be apparent from the description of the present specification and the drawings.

[0013]

An output diode, a transistor, and an FET generated by the flow of an output current of a power supply device.
(Field effect transistor), etc., the voltage drop characteristics of the voltage drop element, a circuit having substantially the same characteristics, similar characteristics are provided, thereby the signal (voltage) that approximates the voltage drop characteristics of the voltage drop element, This is achieved by correcting the reference voltage.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. Although the following embodiments describe AC-DC converters that convert alternating current to direct current, these can also be realized by using a DC-DC converter that converts direct currents to direct currents of different voltages. FIG. 2 shows the configuration of an AC-DC converter that constitutes a main circuit of the power supply device (power supply unit) according to the first embodiment of the present invention. In FIG. 2, 1 is an external AC power supply, 2 is an AC-DC converter having an input terminal (two white circles shown on the left of the figure), 3
Is a current detection resistor, 4 is an operational amplifier, 5 is a ground terminal, 6
Is a voltage-current conversion circuit, 7 is a diode, 8 is a reference voltage source, 9 is an adder, 10 is an operational amplifier, 11 is a main circuit, 1
2 is a signal transmission means, 13 is a diode, 14 is a load, 1
Reference numeral 5 is a DC output terminal.

The external AC power supply 1 is connected to the main circuit 11 inside the AC-DC converter 2. The high potential side output of the main circuit 11 is connected to the non-inverting input terminal of the operational amplifier 10 and the anode side of the diode 13. The low-potential-side output of the main circuit 11 is connected to the inverting input terminal of the operational amplifier 4 and one of the current detection resistors 3. The cathode side of the diode 13 is connected to the DC output terminal 15 of the AC-DC converter 2. The other of the current detection resistors 3 is connected to the ground terminal 5. The load 14 is connected between the DC output terminal 15 and the ground terminal 5. The normal input terminal of the operational amplifier 4 is
It is connected to the ground terminal 5, and the output terminal of the operational amplifier 4 is
It is connected to the input of the voltage-current conversion circuit 6.

The output of the voltage-current conversion circuit 6 is connected to the anode of the diode 7 and to one input terminal of the adder 9. The positive terminal of the reference voltage source 8 is connected to the other input of the adder 9, and the negative terminal of the reference voltage source 8 is connected to the ground terminal 5. The output of the adder 9 is connected to the inverting input terminal of the operational amplifier 10, and the operational amplifier 1
The output of 0 is connected to the main circuit 11 via the signal transmission means 12.

The operation of this embodiment (FIG. 2) will now be described. The AC voltage input from the external AC power supply 1 is AC
It is input to the main circuit 11 inside the DC converter 2 and is converted into a DC voltage in the main circuit 11. The direct current output from the main circuit 11 is supplied from the direct current output terminal 15 to the load 14 via the diode 13, and flows from the earth terminal 5 through the current detection resistor 3 to the main circuit 11 in a closed loop. At this time, the output terminal of the main circuit 11 and the DC output terminal 15
In between, a potential difference determined by the forward voltage drop of the diode 13 occurs. At the same time, the output current of the main circuit 11 flowing to the load 14 also flows to the current detection resistor 3, so that a potential difference determined by the product of the load current and the resistance value of the current detection resistor 3 is generated across the current detection resistor 3. . The operational amplifier 4 amplifies this potential difference and outputs a voltage proportional to the load current.

The voltage-current conversion circuit 6 and the diode 7 are
A circuit for generating a control voltage for correcting a voltage drop caused by the load current flowing through the diode 13 is configured. The voltage-current conversion circuit 6 outputs a current proportional to the load current according to the output voltage of the operational amplifier 4 (voltage-current conversion), and supplies this to the diode 7. If economy allows, the diode 7 may be of the same type and standard as the diode 13. Usually, a small signal element having a smaller current capacity than the diode 13 is used as the diode 7. When the output current of the voltage-current conversion circuit 6 flows,
It is important that the voltage drop characteristics of the diode 13 are substantially the same or similar.

The forward voltage generated in the diode 7 is output as a correction voltage for the voltage drop caused by the diode 13, and is added to the voltage command value of the reference voltage source 8 by the adder 9 in the next stage. Therefore, when a transistor 13 'or the like is used instead of the diode 13 (FIG. 3), it is necessary to use an element having substantially the same forward voltage drop characteristic as the transistor 13' or the like instead of the diode 7 (not shown). ).

The operational amplifier 10 (FIG. 2) constantly compares the output voltage of the main circuit 11 with the output voltage of the adder 9, and the error voltage obtained by the comparison is passed through the signal transmission means 12 to the main circuit. Return to 11. When the load current flows and the forward voltage of the diode 7 is input to the adder 9, the output voltage of the main circuit 11 increases in voltage by the amount of the forward voltage of the diode 7. Therefore, the diode 13 for the load current
If the output current value of the voltage-current conversion circuit 6 and the diode 7 are selected so that the forward voltage of the diode 7 and the forward voltage of the diode 7 with respect to the current output by the voltage-current conversion circuit 6 are substantially the same, Correction control is performed so that the voltage rise of the main circuit 11 cancels the voltage drop of the diode 7.
As a result, a constant voltage that does not depend on the load current is output to the DC output terminal 15 that is the output of the AC-DC converter 2.

According to this embodiment, the output of the AC-DC converter (cathode side of the diode 13) does not have a voltage sense terminal for voltage feedback control, but it is stable and does not depend on the load current. The output voltage can be obtained.

In the present embodiment, correction of a voltage drop having a non-linear characteristic is described assuming that the voltage drop element existing between the output of the main circuit 11 and the DC output terminal 15 is a diode. When the voltage drop element is not a diode but a resistor, a resistor is provided in place of the diode 7 in this configuration, and the linear voltage drop characteristic due to the voltage drop element and the output voltage rise of the main circuit 11 are canceled. As described above, if the constant of the resistance is determined, the voltage drop of the linear characteristic can be corrected. Even if the voltage drop element has a series characteristic of a diode and a resistor, if the diode and the resistor are provided in series instead of the diode 7, the voltage drop having the combined linear and non-linear characteristic is performed as described above. Can also be corrected. Furthermore, if the parasitic resistance of the power supply line existing between the DC output terminal 15 and the load 14 is also included in the voltage drop element, the voltage drop of the power supply line due to the parasitic resistance can be corrected. Thus, stable power supply to the terminal voltage of the load 14 can be realized. In order to secure higher reliability, a plurality of power supply devices having the same configuration may be connected in parallel (FIG. 3). Here, 1 is an external input power source, 11 is a main circuit, and 13 ′ to 1
3 "'is a voltage drop element transistor, FET, 12
Is a signal transmitting means, 10 is a comparison amplifier, 8 is a voltage source, and 14
Is the load. A transistor or FET is used instead of the diode 13 of FIG. Although power supply devices (units) using various voltage drop elements are connected in parallel, it is not necessary to mix them.

In FIG. 3, by monitoring the output voltage and turning on / off the bases and gates of the transistors and FETs, a circuit that can cut off the current when the output of the power supply device (unit) is short-circuited may be used. Incidentally, 13 'indicates an example using a power transistor, 13 "indicates an example using a junction type FET, and 13"' indicates an example using a power MOS-FET. In either case, if an increase in the manufacturing cost of the power supply device is allowed, it is desirable to provide a control circuit 47 for controlling these. In addition, these voltage drop elements are also required to have a function of limiting the reverse flow of current.

Thus, even if the short-circuit element at the power output terminal is eliminated, and even if the voltage sense line is short-circuited, only the faulty power supply unit is automatically disconnected from the power supply system by the cutoff of the output diode or the like.
The system does not go down for the entire power supply.

FIG. 4 shows an AC-D forming a main circuit of a power supply device (power supply unit) showing a second embodiment of the present invention.
The structure of a C converter is shown. 16, 17, 19 are resistors,
18 is a diode. Other than that, the same components as those of the element shown in FIG. 2 are designated by the same reference numerals. Main circuit 1
A resistor 19 is placed between the output of 1 and the anode of the diode 13.
Are connected. One of the resistors 16 is connected to the output of the operational amplifier 4, and the other of the resistors 16 is connected to the anode of the diode 18 and one input terminal of the adder 9. Other configurations are the same as those of the first embodiment shown in FIG.

The operation of this embodiment will now be described with reference to FIG. The difference from the first embodiment is 1).
As a voltage drop element, a series circuit including a resistor 19 and a diode 13 is used. 2) The output voltage of the operational amplifier 4 is used as a means for generating a control voltage for correcting the voltage drop caused by the resistor 19 and the diode 13. Resistance 1
The configuration is such that a series circuit composed of 6, 17 and the diode 18 is used, and the connection point between the resistor 16 and the diode 18 is used as the input to the adder 9. Other circuit operations are the same as in the case of FIG.

The operational amplifier 4 generates a voltage proportional to the load current. This voltage is input to the series circuit composed of the resistors 16 and 17, and the diode 18, and the circuit current flows through these series circuits, whereby the voltage determined by the product of the main circuit current and the resistor 17 and the diode for the main circuit current. 18
The added voltage to the forward voltage of 1 becomes the control voltage for correcting the voltage drop caused by the resistor 19 and the diode 13. This added voltage is applied to the reference voltage source 8 by the adder 9 in the next stage.
Is added to the voltage command value of. As a result, the output voltage of the main circuit 11 is equal to the voltage generated by the resistor 17 and the diode 1
The voltage is increased by the sum of the forward voltage of 8 and the voltage drop caused by the resistor 19 and the diode 13 is corrected.

At this time, the linear component of the voltage drop is corrected by approximating the linear voltage drop generated by the resistor 19 by the voltage drop generated by the resistor 17. Further, the non-linear component of the drop voltage is corrected by approximating the non-linear drop voltage generated in the diode 13 by the forward voltage of the diode 18. Compared with the first embodiment, this embodiment does not require a voltage-current conversion circuit and has a configuration that can realize a simple and low-cost circuit.

FIG. 5 shows the measurement result of the output voltage characteristic with respect to the load current in the circuit of FIG. The horizontal axis represents the load current and the vertical axis represents the output voltage. 48 is the characteristic before the present invention is implemented, and 49 is the characteristic of the circuit to which the second embodiment of the present invention is applied. In addition, also in the first embodiment of FIG. 2, the same characteristics as 49 can be obtained. As is apparent from FIG. 5, according to the present invention, the correction control of the voltage drop effectively acts, the voltage drop with respect to the load current is significantly improved as compared with that before the invention is implemented, and the load current is substantially wide. It has a constant output voltage.

FIG. 6 shows an AC-D constituting a main circuit of a power supply device (power supply unit) showing a third embodiment of the present invention.
The structure of a C converter is shown. In FIG. 6, 20, 21
Is resistance. In addition, the same components as those shown in FIG. 4 are designated by the same reference numerals. One terminal of the resistor 20 is connected to the diode 18 and the resistor 17. One of the resistors 21 is connected to the resistor 16 and the anode of the diode 18. The other terminal of the resistor 20 is the resistor 2
It is connected to the other one and to one input of the adder 9. Other configurations are similar to those of the second embodiment shown in FIG.

The second embodiment differs from the second embodiment in that a resistor 20 and a resistor 21 are provided in order to divide the forward voltage of the diode 18, and the connection point of the resistor 20 and the resistor 21 is connected to the adder 9. Being connected to the input. The forward voltage of the diode 18 becomes a control voltage for correcting the non-linear voltage drop caused by the diode 13, as in FIG. By dividing the forward voltage of the diode 18 with the resistors 20 and 21, it is possible to finely adjust the correction amount for the nonlinear voltage drop of the diode 13.
Other circuit operations are similar to those of the second embodiment shown in FIG. Similar to the second embodiment, this embodiment has a configuration capable of reducing the cost as compared with the first embodiment.

FIG. 7 shows the measurement result of the output voltage characteristic with respect to the load current in the third embodiment. The horizontal axis represents the load current and the vertical axis represents the output voltage. 50 is a characteristic of the third embodiment. As a result of fine adjustment of the non-linear voltage drop caused by the error in the forward voltage between the diode 18 and the diode 13 in FIG. 4, it can be seen that a more constant output voltage was obtained over a wide range of the load current. Also, the resistance 1
Depending on the fine adjustment including the constants of 6 and 17, the output voltage is about 50 mV when the output current is 60 A in FIG.
A gradient can be provided for the load current to raise the output voltage up to. As a result, it is possible to compensate for the loss of series resistance due to the wiring from the output terminal of the power supply device to the load.

FIG. 8 is an AC-DC forming a main circuit of a power supply unit (power supply unit) in the case where the voltage drop element is replaced by an element Q13 'different from the diode in the third embodiment of the present invention. The structure of a converter is shown. Element Q
13 'includes a power transistor, a junction type FET,
There is a power MOS-FET. Whichever is used as the element Q, it is desirable to provide a control circuit 47 for controlling these. The non-linear voltage drop occurring in the element Q is approximated by the forward voltage of the element Q′18 ′ having the same voltage drop characteristic as the element Q. As a result, the non-linear component of the voltage drop due to the element Q is corrected. As the element Q ′, if the increase in the manufacturing cost of the power supply device is allowed, the element having the same standard or model as the element Q may be used. Normally, the element Q'is a small-signal element having a smaller power capacity than the element Q, and when the circuit current flows, an element having substantially the same or similar voltage drop characteristic as the element Q is used.

FIG. 9 shows an AC-D forming a main circuit of a power supply device (power supply unit) showing a fourth embodiment of the present invention.
A configuration in which a plurality of C converters are connected in parallel is shown. Two
-1, 2-n are AC-DC converters, 9 is an adder, 2
Reference numerals 2 and 23 are operational amplifiers, 24 is a diode, and 25 is a signal line. In addition, the same components as those shown in FIG. 2 are designated by the same reference numerals. In FIG. 9, AC-DC
The n converters 2-1 to 2-n have exactly the same circuit configuration and are connected in parallel to the external AC power supply 1 and the load 14. The internal circuit of the AC-DC converter 2-1 will be described below.

The output of the operational amplifier 4 is connected to the normal input terminal of the operational amplifier 23 and the inverting input terminal of the operational amplifier 22, and the output of the operational amplifier 23 is connected to the anode of the diode 24. The inverting input terminal of the operational amplifier 23 is connected to the cathode of the diode 24, the non-inverting input terminal of the operational amplifier 22, the input of the voltage-current conversion circuit 6, and the same terminal of the other AC-DC converter and the signal line 25.
Connected by.

One input of the adder 9 is connected to the output of the operational amplifier 22, the other input of the adder 9 is connected to the positive side of the reference voltage source 8, and the remaining input of the adder 9 is the voltage −.
It is connected to the output of the current conversion circuit 6 and the anode of the diode 7. Other configurations are similar to those in FIG.

The operation of this embodiment will be described with reference to FIG. This embodiment is different from the first embodiment in 1)
AC-DC converters 2-1 to 2-n have n parallel configurations, and 2) the output of the operational amplifier 4 is input to the maximum voltage detection circuit including the operational amplifier 23 and the diode 24, and Input to the operational amplifier 22, the output of the operational amplifier 22 is input to the adder 9, and 3).
The voltage of the signal line 25, which is the output of the maximum voltage detection circuit, is input to the operational amplifier 22 and the voltage-current conversion circuit 6 as well as to another AC-DC converter. Therefore, the difference will be mainly described. The other circuit operations are similar to those of the first embodiment shown in FIG.

The DC current output from the main circuit 11 is supplied from the DC output terminal 15 to the load 14 via the diode 13, and flows from the ground terminal 5 through the current detecting resistor 3 to the main circuit 11 in a closed loop. . This operation is for other AC
The same applies to the -DC converter, and it is possible to flow up to the total value of the output currents of the AC-DC converters 2-1 to 2-n in the load 14.

The output current of each AC-DC converter is output to the output terminal of the operational amplifier 4 as a voltage proportional to the output current, as described in the first embodiment. The operational amplifier 23 and the diode 24 constitute a so-called maximum voltage detection circuit, and due to the connection between the AC-DC converters by the signal line 25, the highest voltage among the output voltages of the operational amplifier 4 of each AC-DC converter. Is output to the signal line 25. That is, the signal line 25 shows the maximum value of the output current of each AC-DC converter. In the operational amplifier 22, the voltage of the signal line 25 is applied to the non-inverting input terminal, and the output voltage of the operational amplifier 4 is applied to one inverting input terminal.

Therefore, in the operational amplifier 22, each AC-
The maximum value of the output current of the DC converter and its own AC
-Equivalent to comparing with the output current of the DC converter, these error voltages are added to the voltage command value of the reference voltage source 8 by the adder 9, and the operational amplifier 10 and the signal transmission means 1 are added.
2. Each AC-D by the voltage feedback control by the main circuit 11.
The output voltage of the main circuit 11 of the C converter changes according to the error voltage so that the output current follows the maximum value. As a result, the output current of each AC-DC converter is made uniform.

The above-mentioned control for making the output current of each AC-DC converter follow the maximum current among them to make the output of each power supply unit uniform is referred to as maximum current follow-up control. The output voltage of each operational amplifier 4 has a value proportional to its own output current, and in the maximum current follow-up control, by making this proportionality coefficient equal between the AC-DC converters, each output current becomes uniform. Be converted.

On the contrary, if the proportional coefficient has a different value in each AC-DC converter, the output current distribution of each AC-DC converter can be changed. For example, in parallel operation of AC-DC converters having different current capacities, it is possible to arbitrarily set the optimum current distribution according to the current capacities of the AC-DC converters. Even in such a situation, the maximum current follow-up control is possible.

Here, an AC-DC converter with a low current output is T, and an AC-DC converter with a current output twice that is T2. The higher converter is not limited to lower integer multiples of output current. The voltage appearing at the output terminal of the operational amplifier 4 of T when T outputs the maximum current is equal to the voltage appearing at the output terminal of the operational amplifier 4 of T2 when T2 outputs the maximum current. The proportional coefficient of the output voltage of the operational amplifier 4 is set. In this parallel connection, if the maximum current follow-up control is performed, that is, if the signal line 25 shown in the circuit configuration of FIG. 9 is provided, the follow-up control with the maximum output current of T2 can be performed. As a result, T
By using a power supply system in which the number of power supplies is one and the number of power supplies is T2 is an even number, it is possible to increase the product lineup of rated output currents without increasing the cost.

At the same time as the maximum current tracking control, the voltage-
As described in the first embodiment, the circuit composed of the current conversion circuit 6 and the diode 7 generates a control voltage for correcting the voltage drop caused by the diode 13.
As a result, the output voltage of the main circuit 11 of each AC-DC converter is controlled to rise by the forward voltage of the diode 7. Instead of the diode 13, another voltage drop element such as a transistor or a FET may be used. Fourth
In the embodiment of FIG. 9 (FIG. 9), unlike the first embodiment, the input of the voltage-current conversion circuit 6 is not the output voltage of the operational amplifier 4 but the voltage of the signal line 25. The voltage of the signal line 25 is the maximum value of the output voltages of the operational amplifier 4 of each power supply unit. AC by maximum current tracking control
-When the output current of the DC converter is equalized, the voltage of the signal line 25 becomes equal to the output voltage of the operational amplifier 4. Therefore, the action of the correction control of the voltage drop caused by the diode 13 in the present embodiment is It is equivalent to the first embodiment.

The voltage increase in the output voltage of each main circuit 11 corresponding to the forward voltage of the diode 7 acts so as to cancel the voltage drop caused by the diode 13, and each AC-DC.
The output voltage of the converter is kept constant with respect to the load current. In addition, the diode 13 according to the present embodiment
In the correction control of the voltage drop caused by, the maximum value of the voltage of the signal line 25, that is, the output current of each AC-DC converter is input. As a result, all ACs connected in parallel
Since the same correction control voltage is applied to the DC converter, it does not affect the output current distribution control by the proportional coefficient of the operational amplifier 4 described above.

According to the present embodiment, the output current distribution control of the AC-DC converters connected in parallel enables parallel redundant operation of the power supply devices, and at the same time, does not affect the control of the output diodes. It is possible to correct the voltage drop of the output voltage caused by the above, and to maintain the output voltage during parallel redundant operation at a constant value without depending on the load current.

Further, in the fourth embodiment, each AC
Since the -DC converter has a circuit configuration in which the DC output terminal 15 which is the output of the AC-DC converter does not have a voltage sense line for voltage feedback control, the factor that induces a short circuit fault in the power supply output is reduced, and the reliability is improved. It is possible to construct a parallel power supply system with high performance.

Further, the output of the main circuit 11 and the DC output terminal 1
5 is connected to the main circuit 11 by the diode 13 provided between
Backflow of current to the AC-DC converter is prevented, and hot-swap maintenance can be performed during parallel operation of the AC-DC converter.

In the embodiment of FIG. 9, a diode is used as the voltage drop element existing between the main circuit 11 and the DC output terminal 15, and the correction of the voltage drop having the nonlinear characteristic is described. The linear voltage drop of the voltage drop element due to the resistance or the like, or the voltage drop including the linear component and the non-linear component due to the diode and the resistance or the like can be corrected as in the case of the first embodiment. Further, in FIG. 9, a voltage drop correction circuit caused by the voltage drop element is described with reference to FIG. In FIG. 9, the correction circuits of FIGS. 4 and 6 may be used, and the correction effect of the voltage drop at this time is as described in FIGS. 4 and 6.

FIG. 10 is a block diagram showing a fifth embodiment of the present invention, in which a power source is applied when high reliability is required for a system such as a RAID type disk storage device.
In the RAID type disk storage device, a plurality of disk storage devices are connected to a parallel redundant power supply system composed of a plurality of power supply devices, and a system having a plurality of series is provided as one system. In the RAID type disk storage device, as shown in FIG.
It is controlled so as to extend over each series, and data can be recovered as long as the number of series is within the system tolerance for system down of each series.

Therefore, in order to ensure the reliability of the storage device system, it is required to avoid system down of each system, and the power supply device has a parallel redundancy function including hot-swap maintenance and output. A circuit configuration that eliminates the short-circuit element at the end is required.

Further, with the recent decrease in the voltage of semiconductor components, the allowable fluctuation range of the power supply voltage tends to be narrowed. In order to secure the reliability of the recorded / reproduced data, it is necessary to suppress the fluctuation of the output voltage of the power supply device, which causes the operation margin of the circuit to decrease. Further, in the RAID device, as shown in FIG. 10, the disk storage device is added, and the load current amount of the power supply device changes significantly. Therefore, in the power supply device, it is necessary to stabilize the output voltage against changes in the load current. In view of these circumstances, the power supply device of the present invention is indispensable for an electronic system that requires high reliability.

[0053]

According to the present invention, the voltage drop of the output voltage of the power supply caused by the output current of the main circuit flowing to the voltage drop element is generated from the signal proportional to the output current of the main circuit. The output voltage of the main circuit is corrected and controlled by the correction voltage having the characteristic similar to the voltage drop so as to increase the voltage value by the voltage drop of the voltage drop element. Therefore, the output voltage of the power supply device has the effect of obtaining a constant voltage that does not depend on the load current.

Further, if the parasitic resistance existing between the output of the power supply device and the load is included in the voltage drop element to compensate,
The output voltage can be corrected for the voltage drop of the power supply line.

According to the parallel redundant operation of the power supplies by the maximum current tracking control, the voltage drop correction control is performed because the correction voltage is made from the maximum value of the output voltages of the power supplies.
The same correction control is given to all the power supply devices. Therefore, the output current distribution of each power supply unit is not affected at all, and stable output current distribution control is performed, and at the same time, a constant output voltage independent of the load current is obtained.

Since the circuit configuration does not have a voltage sense line for voltage feedback control on the load side of the voltage output terminal of the power supply device, elements that induce a short-circuit fault in the output of the power supply device are reduced. In addition, since the reverse current limiting means such as a diode is provided in the voltage drop element, the reverse current of the current to the power supply main circuit is limited or prevented. A highly redundant parallel power supply system can be constructed.

The control circuit of the power supply device of the present invention can be realized by semiconductor parts, and not only the circuit by individual parts but also the effect of downsizing and cost reduction by an integrated circuit.

Further, the present invention is a technique for keeping the output voltage of the power supply unit constant, but the features that are greatly different from the conventional technique will be described as an effect different from the above. FIG. 11 shows a configuration diagram of the power supply circuit. In FIG. 11, 40 is a power supply device, 41 is an external input power supply, 42 is a converter main circuit, 4
3 is an output diode (voltage drop element Q), 44 is a load,
Reference numeral 45 is an external input current source, 46 is a power supply output terminal, and 47 is a ground terminal. In FIG. 11, an external input power source 41
Is connected to the converter main circuit 42 inside the power supply device 40. The high potential side output terminal of the converter main circuit 42 is connected to the power supply output terminal 46 via the output diode 43. The low-potential-side output terminal of the converter main circuit 42 is connected to the ground terminal 47. The load 44 is the power output terminal 4
6 is connected between the ground terminal 47 and the external input current source 4
5 is an anode of the output diode 43 and a ground terminal 47.
Is connected in the direction in which the current flows into the output diode 43.

The features of the present invention will be described below in comparison with the prior art. In FIG. 11, the voltage input from the external input power supply 41 is converted into a desired DC voltage by the converter main circuit 42 and is applied to the load via the output diode 43. The voltage of the power supply output terminal 46, which is the output of the power supply device, has a voltage value lower than the output voltage of the converter main circuit 42 by the forward voltage of the output diode 43.

When the current of the external input current source 45 is zero,
In the prior art, voltage feedback control of the voltage of the power supply output terminal 46, and in the present invention, the voltage drop correction control keeps the voltage of the power supply output terminal 46 constant regardless of the load current in either technology. This is as described above.

On the other hand, when a current flows from the anode of the output diode 43 by the external input current source 45 and the forward voltage of the output diode 43 increases, the conventional technique uses the voltage feedback control to control the voltage of the power output terminal 46. However, according to the present invention, the voltage of the power supply output terminal 46 decreases as the forward voltage of the output diode 43 increases, and the prior art and the present invention can be clearly distinguished. The above is one of the features of the present invention, which can be easily confirmed from the outside of the power supply device as described above.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram showing a power supply device (unit) required for a power supply system used in an electronic system requiring high reliability and a parallel connection of these.

FIG. 2 is a circuit configuration diagram of a power supply device (unit) showing a first embodiment of the present invention.

FIG. 3 is a circuit configuration diagram showing a power supply device (unit) when the diode 13 of FIG. 2 is another voltage drop element.

FIG. 4 is a circuit configuration diagram of a power supply device (unit) according to a second embodiment of the present invention.

FIG. 5 is a diagram showing a measurement result of the second embodiment of the present invention.

FIG. 6 is a circuit configuration diagram of a power supply device (unit) showing a third embodiment of the present invention.

FIG. 7 is a diagram showing measurement results of the embodiment of FIG.

FIG. 8 is a power supply device (unit) in which the diode 13 is replaced with a voltage drop element Q or the like in the embodiment of FIG. 6;
2 is a circuit configuration diagram of FIG.

FIG. 9 is a circuit configuration diagram showing a power supply device (unit) and a parallel connection thereof according to a fourth embodiment of the present invention.

FIG. 10 is an electronic system R that requires high reliability.
It is a figure which shows the structural example at the time of applying this invention to an AID system disk storage device.

FIG. 11 is a diagram showing a circuit configuration for verifying characteristics of a power supply device (unit) according to the present invention.

FIG. 12 is a circuit configuration showing a conventional power supply device (unit) and their parallel connection.

[Explanation of symbols] 1 ... External AC power supply, 2, 2-1 to 2-n ... AC-D
C converter, 3 ... Current detection resistor, 4, 10, 2
2, 23 ... Operational amplifier, 5, 47 ... Ground terminal,
6 ... Voltage-current conversion circuit, 7, 13, 18, 24, 3
6, 43, 51 ... Diode, 8 ... Reference voltage source,
9 ... Adder, 11, 35 ... Main circuit, 12 ... Signal transmission means, 13 '... Voltage drop element Q different from diode, 18' ... Element having voltage drop characteristics similar to element Q Q ', 14, 39, 44 ... Load, 15 ... DC output terminal, 16, 17, 19, 20, 21 ... Resistance, 25
...... Signal line, 26 …… Switching circuit, 27 …… Transformer, 28 …… Rectifying and smoothing circuit, 29 …… Driving circuit,
30 ... Comparator, 31 ... Error amplifier, 32 ... Oscillator, 33 ... Triangular wave generator, 34, 41 ... External input power supply, 36 '... Transistor, 36 "... Junction type FE
T, 36 "'... MOS-FET, 37 ... Comparative amplifier,
38 ... voltage source, 40 ... power supply device, 42 ... converter main circuit, 45 ... external input current source, 46 ... power supply output terminal, 47 ... voltage drop element control circuit.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroyuki Kurosawa 2880, Kozu, Odawara-shi, Kanagawa Hitachi Ltd. Storage Systems Business Department (56) Reference JP-A-9-23653 (JP, A) JP-A-8 −95649 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H02M 3/155 H02J 1/10 H02M 7/12

Claims (26)

(57) [Claims] 1. A first input terminal for inputting power, a main circuit connected to the first input terminal for converting input power into a DC output, and a main circuit connected to an output section of the main circuit, A first voltage drop element having a function of limiting the reverse flow of the output of, a reference voltage source for generating a reference voltage, and a first circuit for outputting a signal proportional to the output current of the output part of the main circuit, A second circuit for returning a maximum signal obtained by comparing a signal input from the outside of the power supply device and an output signal from the first circuit to the signal from the outside, and outputting the signal. A third circuit for comparing the output signal of the first circuit with an external signal to which the maximum signal is fed back, and adding the result to a reference voltage generated by the reference voltage source; The first voltage drop element with respect to an external signal A second voltage drop element for generating a voltage drop characteristic that is substantially the same as or similar to the voltage drop characteristic and adding it to the reference voltage generated by the reference voltage source; the third circuit and the second voltage drop element A power supply device comprising: a fourth circuit that compares the reference voltage to which the output from the main circuit is added with the voltage extracted from the output of the main circuit and feeds the result back to the main circuit. 2. The power supply device according to claim 1, wherein the first voltage drop element and the second voltage drop element are any one of a diode, a transistor, and a FET. A power supply device characterized by being present. 3. The power supply device according to claim 1, wherein the second voltage drop element finely adjusts the voltage drop characteristic that is substantially the same as or similar to the voltage drop characteristic of the first voltage drop element. A power supply device for adding to the reference voltage of the first circuit. 4. The power supply device according to claim 1, wherein the signal input from the self power supply device is shared with another power supply device. 5. An input terminal for inputting power, a main circuit connected to the input terminal for converting input power into a DC output, and an output section of the main circuit for limiting backflow of the output of the main circuit. A first voltage drop element having a function of: a reference voltage generation source for generating a reference voltage; and a voltage drop characteristic that is substantially the same as or similar to the voltage drop characteristic of the first voltage drop element. A second voltage drop element added to a reference voltage generated by a source and comparing the output of the main circuit with the added reference voltage of the output from the second voltage drop element and comparing the result to the main circuit. A power supply device having a circuit for feeding back to the power supply device. 6. The power supply device according to claim 5, wherein the second voltage drop element is any one of a diode, a transistor, and a FET. . 7. The power supply device according to claim 5, wherein the second voltage drop element finely adjusts the voltage drop characteristic substantially the same as or similar to the voltage drop characteristic of the voltage drop element, A power supply device characterized by being added to a reference voltage. 8. The power supply device according to claim 1, wherein the input terminal inputs AC power or DC power. 9. An input terminal for inputting power, a main circuit connected to the input terminal for converting input power into a DC output, and an output section of the main circuit for limiting backflow of the output of the main circuit. A first voltage drop element having a function of generating a reference voltage, a reference voltage generation source for generating a reference voltage, a voltage drop characteristic substantially the same as or similar to the voltage drop characteristic of the first voltage drop element, and the reference voltage A second voltage drop element added to a reference voltage generated by a source and comparing the output of the main circuit with the added reference voltage of the output from the second voltage drop element and comparing the result to the main circuit. Power supply system having two or more power supply devices each having a circuit for feeding back to each other, and each of the two or more power supply devices having a signal line connecting the two or more power supply devices to each other. . 10. The power supply system according to claim 9, wherein the first voltage drop element is any one of a diode, a transistor, and a FET. . 11. The power supply system according to claim 9, wherein the second voltage drop element finely adjusts the voltage drop characteristic substantially the same as or similar to the voltage drop characteristic of the voltage drop element, A power supply system characterized by being added to a reference voltage. 12. The power supply system according to claim 9, wherein the signal line connecting the two or more power supply devices to each other is connected to a reference voltage generated by the reference voltage source of the two or more power supply devices. A power supply system, wherein the power supply system is shared by the two or more power supply devices in order to input the maximum value of the output current of each of the power supply devices. 13. The power supply system according to claim 9, wherein the input terminal is AC power or DC power. 14. A first input terminal for inputting power, a conversion circuit connected to the first input terminal for converting input power into a DC output, and a conversion circuit connected to an output section of the conversion circuit. A voltage drop element having a function of limiting the reverse flow of the output of the device, a reference voltage source for generating a reference voltage, and a first circuit for outputting a signal proportional to the output current of the output section of the conversion circuit. A second circuit for returning a maximum signal obtained by comparing a signal input from the outside of the power supply device and an output signal from the first circuit to the signal from the outside, and outputting the signal. A third circuit for comparing the output signal of the first circuit with an external signal to which the maximum signal is fed back, and adding the result to a reference voltage generated by the reference voltage source; The first voltage with respect to an external signal A second voltage drop characteristic according to the voltage drop characteristic of the voltage drop element, which is added to the reference voltage generated by the reference voltage source;
Of the voltage drop element, the reference voltage added with the outputs from the third circuit and the second voltage drop element, and the voltage extracted from the output of the conversion circuit, and the result is converted into And a fourth circuit for feeding back to the circuit. 15. The power supply device according to claim 14, wherein the first voltage drop element and the second voltage drop element are any one of a diode, a transistor, and a FET. A power supply device characterized by being present. 16. The power supply device according to claim 14, wherein the second voltage drop element finely adjusts the voltage drop characteristic similar to the voltage drop characteristic of the first voltage drop element. A power supply device characterized in that it is added to the reference voltage of the first circuit. 17. The power supply device according to claim 14, wherein the signal input from the self power supply device is shared with another power supply device. 18. An input terminal for inputting power, a conversion circuit connected to the input terminal for converting input power into a DC output, and an output section of the conversion circuit for limiting backflow of the output of the conversion circuit. A first voltage drop element having the function of: a reference voltage generation source for generating a reference voltage; and a voltage drop characteristic similar to the voltage drop characteristic of the first voltage drop element, generated by the reference voltage source. The output of the second voltage drop element added to the generated reference voltage and the conversion circuit is compared with the reference voltage to which the output from the second voltage drop element is added, and the result is fed back to the conversion circuit. A power supply device having a circuit. 19. The power supply device according to claim 18, wherein the second voltage drop element is any one of a diode, a transistor, and a FET. . 20. The power supply device according to claim 18, wherein the second voltage drop element performs a fine adjustment of a voltage drop characteristic similar to the voltage drop characteristic of the voltage drop element to obtain the reference voltage. A power supply device characterized by being added. 21. The power supply device according to claim 14 or 18, wherein the input terminal is AC or DC power. 22. An input terminal for inputting electric power, a conversion circuit connected to the input terminal for converting the input power into a DC output, and an output section of the conversion circuit for limiting backflow of the output of the conversion circuit. A first voltage drop element having the function of: a reference voltage generation source for generating a reference voltage; and a voltage drop characteristic similar to the voltage drop characteristic of the first voltage drop element, generated by the reference voltage source. The output of the second voltage drop element added to the generated reference voltage and the conversion circuit is compared with the reference voltage to which the output from the second voltage drop element is added, and the result is fed back to the conversion circuit. A power supply system comprising: two or more power supply devices each having a circuit; and each of the two or more power supply devices has a signal line connecting the two or more power supply devices to each other. 23. The power supply system according to claim 22, wherein the first voltage drop element is any one of a diode, a transistor, and a FET. . 24. The power supply system according to claim 22, wherein the second voltage drop element finely adjusts a voltage drop characteristic similar to the voltage drop characteristic of the voltage drop element to obtain the reference voltage. A power supply system characterized by being added. 25. The power supply system according to claim 22, wherein the signal line connecting the two or more power supply devices to each other is connected to a reference voltage generated by the reference voltage source of the two or more power supply devices. A power supply system, wherein the power supply system is shared by the two or more power supply devices in order to input the maximum value of the output current of each of the power supply devices. 26. The power supply system according to claim 22, wherein the input terminal is AC or DC power.