JPS60223429A - Dc power source - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION fal Technical Field of the Invention The present invention relates to a DC power supply device comprising a plurality of power supply unit groups that perform parallel operation to supply DC power to a load of an electronic device.

(bl Background of the Technology) Conventionally, the power consumption of DC power supplies to electronic devices has increased as the functions of electronic devices have increased, and a DC power supply device that supplies a large amount of power has become necessary. As a result, power transformers and other peripheral electronic components have been miniaturized, and high-frequency switching power supply circuit systems have been widely put into practical use, making it easy to control the rise and fall of the power supply voltage. A switching circuit that turns on/off the gate of a switching element under the control of a control circuit, and converts the input power supply into a high-frequency rectangular wave voltage intermittently, and a transformer transforms and rectifies the high-frequency rectangular wave voltage from this switching circuit. It is a DC-DC converter that obtains a DC output by converting it into DC using a smoothing circuit,
This configuration constitutes one power supply unit configuration.

Since electronic devices usually use semiconductor integrated circuits, large-scale semiconductor integrated circuits, etc., the power supply voltage of DC power supplies that supply large amounts of power is a low voltage power supply of about 5 volts.
It supplies a large current of several hundred to several thousand amperes. For that reason,
Multiple power supply units, each with a power capacity of several hundred amperes, are operated in parallel to provide direct current power to electronic equipment.

fQ) Prior Art and Problems The conventional DC power supply of this type of DC power supply device will be described below. FIG. 1 shows a wiring diagram of a DC power supply device consisting of a plurality of power supply unit groups that operate in parallel and supply DC power to an electronic device load.

1 a--4n indicates a group of power supply units operated in parallel, and 2 indicates a load. Each of the power supply units 1a to 1n individually receives DC input power, outputs the input power to a DC power supply via a high frequency switching power supply circuit, and collectively supplies the output DC power to the load 2. There is. The individual power supply units of the power supply unit group 1a-4n that operate in parallel have the same circuit configuration, and the power supply circuit of one of the power supply units will be described as a representative. FIG. 2 shows a block diagram of the circuit configuration of the power supply unit la of FIG. 1, and the same objects are indicated by the same symbols throughout the drawings. 3a is a switching element.

4a is a transformer, 5a is a rectifier and smoothing circuit, 6a is a galvanometer, 7a is a rectifier, 8a is a converter, 9a is a reference limit current setting resistor, 10a is a converter, 11a
indicates the reference voltage setting resistor. In the case of the power supply unit 1n, the above-mentioned suffix a is replaced with n.

In Fig. 2, the input power is received from the input power supply side a,
It is turned on and off by the switching element 3a to obtain an intermittent DC wave. Next, the DC intermittent wave is transmitted to the secondary side through the transformer 4a, and DC power is supplied to the load 2 from the DC output side via the rectifying and smoothing circuit 5a.

This power supply unit (Ia) is provided with a current limiting circuit and a constant voltage circuit. The current limiting circuit has a galvanometer 6a that detects the current flowing to the primary side of the transformer 4a, and detects the current flowing to the primary side with the galvanometer 6a, and outputs a detected voltage to one terminal of the converter 8a via a rectifying element 7a. It is applied as a level and compared with a reference voltage level VAa provided by a reference limit current setting resistor 9a of the ten terminals of the converter 8a. When the current value detected by the galvanometer 6a exceeds the limit current value set by the reference limit current setting resistor 9a, the converter 8a suppresses the on/off operation of the switching element 3a.
Limits the current on the next side and limits the output current.

Further, the constant voltage circuit applies the output voltage of the DC output side to one terminal of the converter 10a, and the reference voltage level V
Compare with Va. The output voltage is the reference voltage setting resistor 11a.
When the reference voltage level VVa set in is exceeded, the converter lla suppresses the pulse width of the on/off operation of the switching element 3a to lower the output voltage, and when the output voltage is lower than the reference voltage level ■Va, The output voltage is increased by controlling the pulse width of the on/off operation of the switching element 3a, and serves as a constant voltage circuit that always maintains the output voltage constant even if the output current increases or decreases. A plurality of these power supply units are operated in parallel to supply high-power DC power to the load of electronic equipment.

Next, current sharing for each power supply unit that operates in parallel and supplies DC power will be explained with reference to output voltage-current characteristic diagrams shown in FIGS. 3 and 4.

To simplify the explanation, we will use an example in which two power supply units supply DC power to the load. Further, in all output voltage-current characteristic diagrams, the vertical axis indicates the output voltage, and the horizontal axis indicates the output current. In FIG. 3, when the two power supply units are a power supply unit 1-1a and a power supply unit 1-1b, the power supply capacity of the power supply unit 1-1a has an output voltage-current characteristic of A characteristic (v1-II).

The power supply unit 1b has a B characteristic (V2-12) output voltage -
It has current characteristics. When these two power supply units are operated in parallel, the output voltages of the two power supply units will differ somewhat depending on the constants of component parts, adjustment levels, wiring lengths, etc. It is assumed that the output voltage v1 of the power supply unit 1a is higher than the output voltage v2 of the power supply unit 1a, and the current sharing between the two power supply units operated in parallel is expressed as the output voltage - in Fig. 4.
Shown in the current characteristic diagram. First, DC power is supplied to the load by the A characteristic of the power supply unit 1a, DC power to the full capacity of the limit current value of the power supply unit a is supplied, and then DC power is supplied by the B characteristic of the power supply unit 1a. be done.

That is, the output current I3 at the intersection point C with the output voltage v2 of the load line (0-C) indicating the output current characteristics with respect to the output voltage of the load.
is the output current value when the power supply uni-so) la and the power supply uni-node 1b are operated in parallel, the power supply uni-so Ha shares the maximum capacity current ■1, and the power supply uni-no.
(I3-11) of 2 is shared. Therefore, of course.

12 > 13-Il 11 > 13-II, and the current sharing of the output current between 11 and (13-11) is not balanced.

This conventional DC power supply that performs parallel operation does not have an output current balance circuit, and the output currents of the power supply units are balanced by setting the output voltage level commensurate with the load current capacity. If the impedance of the power supply unit is extremely low, even if you set the output voltage level and balance the output current, if the voltage setting level of each power supply unit deviates by even a few mV, the balance will shift, making adjustment extremely difficult. Even if the settings are successful, the balance may shift again due to input voltage fluctuations, load fluctuations, temperature fluctuations of the two components, changes over time, etc. Furthermore, an output current that is full to the limited current capacity flows through a specific power supply unit, which may cause a reduction in the reliability of that power supply unit. If one power supply unit fails due to some kind of failure, the current distribution of each power supply unit will change significantly, resulting in large transient output fluctuations, and the output voltage will temporarily decrease due to the inability to follow the output fluctuations. It had the disadvantage that it fluctuated over time.

fdl OBJECT OF THE INVENTION The present invention aims to solve the conventional drawbacks of difficulty in adjusting the output current balance and vulnerability to output fluctuations, which also causes a decrease in reliability.

fe) Structure of the Invention The above object is to supply DC power to a load of an electronic device from a plurality of power supply unit groups operated in parallel.

voltage comparison means for comparing the load impedance of the electronic device, a reference voltage by a reference voltage setting resistor, and a DC output voltage supplied to the load of the electronic device; and an inflow current on the input side of each of the plurality of power supply units. current limiting means for detecting and comparing the detected voltage with a reference voltage level of a reference limited current source to limit the current; and a reference limiting current of the current limiting means of each of the plurality of power supply units based on the output of the voltage comparing means. and control means for controlling a reference voltage level of a reference current source of the current limiting means, the control means of the plurality of power supply unit groups controlling the reference voltage level of the reference limited current source of the current limiting means based on the output of the voltage comparing means. This is achieved by the present invention, which is configured to vary the level.

In other words, in a DC power supply device that operates multiple power supply unit groups in parallel to supply DC power to the load of electronic equipment, the voltage that compares the load impedance of the electronic equipment, the reference voltage determined by the reference voltage setting resistor, and the DC output voltage. Using the output of the comparison means, the control means controls the reference voltage level of the reference limiting current source of the current limiting means of each of the plurality of power supply unit groups;
By varying the reference voltage level of the reference limited current source with an output current commensurate with the output current of the load, the current limit amount of each power supply unit group is changed and the output current is supplied. Even if the impedance of the power supply unit is extremely low, it is possible to limit the output current of each power supply unit according to the impedance and set a limit current value commensurate with the load current capacity to maintain balance.
Even if the individual output voltage setting levels are off by a few millivolts, the output current remains unbalanced due to input voltage fluctuations, load fluctuations, temperature fluctuations of one component, changes over time, etc.

Furthermore, reliability is improved as the load is no longer placed only on a specific power supply unit, and during parallel redundant operation,
Even if one power supply unit breaks down due to some kind of failure and the current sharing of each power supply unit changes, the output fluctuations will be small transiently, so the DC power supply can minimize the output fluctuations. It provides:

(fl Embodiment of the Invention An embodiment of the present invention will be described below. Fig. 5 shows a circuit configuration block diagram in which a current balance circuit according to the present invention is provided in a DC power supply device. Two power supply units are operated in parallel and the load is This will be explained using an example in which DC power is supplied to 21a, 2.
1b is a power supply unit.

22a and 22b are diodes, 23a and 23b are resistors,
24 is a converter, and 25 is a reference voltage setting resistor.

The output terminal of the converter 24 is connected to the child terminal side of the converter 8a of the power supply unit 21a via a diode 22a and a resistor 23a connected in series. Similarly, a diode 22 is connected to the child terminal side of the converter 8b of the power supply unit 21b.
b is connected to the output terminal of converter 24 via resistor 23b. Ten potentials of the output voltage are applied to one terminal of the converter 24, and a reference voltage level Vo by a reference voltage setting resistor 25 is applied to the ten terminal.

The other end of the reference voltage setting resistor 25 is connected to one potential of the load 2, and the reference voltage level vO is varied by the reference voltage setting resistor 25 and the load impedance of the load 2. This converter 24, diodes 22a, 22b and resistor 23
A and 23b form a current balance circuit.

In FIG. 5, the high-frequency switching power supply function and constant voltage circuit of the power source unit nodes 21a and 21b are the same as those described above, and will therefore be omitted. Current) The procedure for balancing the current of each power supply unit using a lance circuit will be explained. When the output voltage of load 2 maintains a specified constant voltage and the output current is large, the impedance of load 2 on the output side is small, so the reference voltage level vO of converter 24 is low (con) < - than the output side of converter 24. Diode 22a, 2
2b and resistor 23a.

23b, the reference voltage level of the reference voltage level VAa and the reference voltage level VAb of each converter 8a, 8b is increased. Therefore, each power supply unit 21a.

The limit current value of 21b increases and each output current increases.

When the output current value is small, the impedance of load 2 is high, the reference voltage level vO of converter 24 becomes high, and the reference voltage level of each converter 8a, 8b is low. Therefore, the limit current value of each power supply unit 21a, 21b is suppressed in a decreasing direction, and each output current is decreased.

In this way, the current balance circuit function operates to vary the limiting current value of the power supply unit 21a, 21b by increasing or decreasing the output current of the load 2, and to average the current sharing.

FIG. 6 shows an output voltage-current characteristic diagram during parallel operation with current balance. When the load 2 is the load line (0-D), the power supply unit 21a supplies only 14 minutes of output current due to current limitation, and the power supply unit 21b supplies the output current (13-I).
4) Supply minutes. That is.

14 = I3-I4, and balanced currents with the same output current value flow from the power supply unit 21a and the power supply unit 21b.

Therefore, even if the impedance on the output side is extremely low, it can be varied according to the impedance, so the output current of the power supply units can be balanced by setting the current limit value commensurate with the load current capacity. be able to. Although one embodiment of the current balance circuit according to the present invention has been described in terms of parallel operation using two power supply unit nodes, the number of power supply unit groups operated in parallel is not limited to two.

The limiting current value may be set based on the number of power supply units operated in parallel and the load current capacity.

(gl As described in detail of the invention, in a DC power supply device that operates a plurality of power supply units in parallel to supply DC power to the load of electronic equipment, the load impedance of the electronic equipment and the reference voltage setting resistance are with reference voltage.

Accordingly, the reference voltage level of the reference limited current source of the current limiting means of the plurality of φ power supply units is controlled by the control means, and the reference voltage level of the reference limited current source is varied with an output current commensurate with the output current of the load. According to the present invention, the output current is supplied by changing the current limit amount of each power supply unit group.

Balance can be achieved by setting a limiting current value commensurate with the load current capacity, and the balance of the output current will not be disrupted even by input voltage fluctuations, load fluctuations, temperature fluctuations of two parts, changes over time, etc. The load is no longer borne only by the power supply unit, improving reliability, and even if the current sharing of each power supply unit changes, output fluctuations can be minimized, among other effects.

[Brief explanation of the drawing]

Figure 1 is a wiring diagram of a DC power supply device consisting of a group of multiple power supply units that operate in parallel to supply DC power to a load, Figure 2 is a block diagram of the circuit configuration of a conventional power supply unit, and Figure 3 is a diagram of each power supply unit. Figure 4 is an output voltage-current characteristic diagram of the output current sharing when two conventional power supply units are operated in parallel, Figure 5 is a circuit configuration block diagram of the DC power supply of the present invention. , FIG. 6 shows an output voltage-current characteristic diagram of the output current distribution of each power supply unit according to the present invention. In the drawing, 2 is a load, 3a and 3b are switching elements, 4a and 4b are transformers, and 5a and 5b are rectifier and smoothing circuits. 6a and 6b are galvanometers, 7a and 7b are rectifier elements,
8a 8b, 10a, 10b, 24 are converters,
9a and 9b are reference limit current setting resistors, Ila and ll
b is a reference voltage setting resistor. 21a and 21b are power supply units, 22a and 22b are diodes, 23a and 23b are resistors, and 25 is a reference voltage setting resistor, respectively. 5 dormitory I shout 6 guest 3 drunken dormitory 4vlJ gourd η wo flow (I) - 'J#s drunken Ill 2/a 1 go" 4 ? 1 " 1 prey 311 ′〒 7a-/〒 7a-/〒 ′arrival 2.32 ■ Zeng 1b Su 5b 1, 1 Ding 11 JP-A-Sho GO-223429 (6) Entertainment trfJ Peng Current (I) −

Claims (1)

[Claims] DC power is supplied to the load of the electronic device from a plurality of power supply units operated in parallel, and a reference voltage based on the load impedance of the electronic device and a reference voltage setting resistor, and a DC output voltage to be supplied to the load of the electronic device are set. a voltage comparing means for comparing; a current limiting means for detecting an inflow current on the input side of each of the plurality of power supply unit groups and comparing it as a detected voltage with a reference voltage level of a reference limiting current source to limit the current; and control means for controlling the reference voltage level of the reference limited current source of the current limiting means of each of the plurality of power supply units by the output of the comparison means, A direct current power supply device, characterized in that the control means of the power supply unit group is configured to vary the reference voltage level of the reference limited current source of the current limiting means.