JPS60110020A - Power supply stabilizing system - Google Patents

Abstract

PURPOSE:To facilitate an easy balance control and to improve the stability of output voltage by feeding the output current of a power supply unit back to an error detecting circuit for each of power supply units which are driven in parallel to each other. CONSTITUTION:An output current feedback resistance 13 is connected between the DC output side (b) of an error detecting resistance 10 and the single side of a reference voltage source 12. An AC power supply is received from the primary power supply side (a) and converted into a DC. Then a DC power supply is fed to a load from the side (b). An overcurrent detecting circuit 8 detects the current flowing to the primary side of a transformer 7 and transmits an overcurrent signal to a pulse width control circuit 4 when the primary side has an overcurrent. Thus a power supply unit PSU1 is protected. For the output voltage, the output detection voltage has a high level when the output current increases by an output current feedback resistance 13. An error detector 11 compares an error to the reference voltage and then transmits an error voltage signal to the circuit 4 in the direction where the output voltage is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (81) Technical Field of the Invention The present invention relates to a power supply stabilization method for a power supply device comprising a plurality of power supply unit groups operated in parallel for supplying power to electronic equipment.

(bi Background of the Technology) Conventionally, power consumption for power supply to electronic devices has increased as the functions of electronic devices have increased, and a power supply device that supplies a large amount of power has become necessary. Transformers and other peripheral electronic components have become smaller, and the high-frequency switching power supply circuit system, which makes it easy to control the rise and fall of the power supply voltage, has become widely available.This high-frequency switching power supply circuit F78 system transforms commercial power. Transform the voltage with a device?
A switching circuit that converts the li source rectifier into a high-frequency rectangular wave voltage by turning on and off the gate of a switching element under the control of a control circuit, and converting the DC power into a high-frequency rectangular wave voltage. The high frequency rectangular wave voltage from the switching circuit is transformed by a transformer and rectified by 11z.
This is a method in which the DC output is converted to DC by 11/11 along the path. A high frequency switching type power supply circuit such as the one shown in FIG.

Usually, electronic devices are semiconductor built-in circuits, large-scale semiconductors 1] 5
Since a product circuit or the like is used, the power supply voltage of the power supply device that supplies large power is a low voltage power supply of about 5 pol]-, and a large current of several hundred to several thousand amperes is supplied. For that reason 2”
Multiple unino power supplies, each with a power capacity of several hundred amperes, are operated in parallel to serve as a power source for electronic equipment.

(0) Prior Art and Problems The conventional circuit configuration of this type of power supply device will be described below. FIG. 1 shows a wiring diagram for parallel operation 11.5 of a power supply device consisting of a plurality of power supply unit groups that supply a load. Old-41n is a group of power supply units operated in parallel, and each power supply unit Old-IJn clearly receives AC power,
AC power is converted to DC power, and the output DC power is collectively supplied to the load side 2. The power supply control of the power supply unit group U l-11n that performs parallel operation is performed by the power supply control device 3.
The power source is controlled by the power control device 3, and power on/off, etc. are controlled by the A on/off control signal of the power source control device 3.

Parallel operation is also performed between the power supply unit groups.The individual power supplies 11n and 7-2 have the same circuit configuration, and one power supply unit among them will be explained as a representative. FIG. 2 shows a block diagram of the circuit configuration of the old power supply unit. Throughout the figures, the same objects are indicated by the same symbols. Reference numeral 4 indicates a pulse width control circuit, and the pulse width control circuit 4 is controlled by the power on/off signal from the power supply control device 3. The on/off of the h source is controlled. Pulse width control circuit A includes switching elements 5a, 5
Controls the on/off switching pulse width of h. −
AC power is received from the blowing mold source side a, and the i! is rectified through the rectifier circuit 6. The r current is turned on and off by switching elements 5a and 5b to obtain intermittent DC waves. Next, the DC intermittent wave is transmitted to the secondary side through the transformer 7, and the rectifier circuit l? DC power is supplied to the load via the DC output side through h.

This old power supply unit is equipped with an overcurrent protection circuit for the power supply unit and a constant voltage circuit for the output voltage.

The overcurrent detection circuit 8 has a detector 8a that detects the current flowing to the primary side of the transformer 7, and when the current on the negative side becomes an overcurrent, it sends out an overcurrent (interval) to the pulse width control circuit 4. ,
It plays the role of a protection circuit to protect the old power supply unit.

In addition, on the output circuit side, in order to detect the output voltage of the DC output side, an error detection resistor 1 and an error detection resistor 10 are connected in series, and one of the error detection resistors 9 is connected to the DC output side. On the + side, one end of the error detection resistor IO is connected to an example of the DC output side, and the error detection resistor 9 and the error detection resistor 10 are connected to the DC output side.
The detection voltage of the output voltage is input to one side input terminal of the EL difference detector 1 from the connection point of Ru.

The error detector 11 compares the error between the detected output voltage and the normal voltage, and the error detector 11 sends an error voltage signal to the pulse width control circuit 4, and the pulse! It plays the role of a constant voltage circuit that stabilizes the output voltage by controlling the on/off pulse width of the switching elements 5a and 5h under the control of the control circuit 111h4.

FIG. 5 shows an output voltage/current characteristic diagram during parallel operation in which Masatomi is operated. Assuming that there are three power supply units, each power supply unit 1- is set to 01.02.0.
3, and the old power supply unit operates in parallel.

[Because there is a slight difference between the output voltages of 2 and 113.

Drawing -1-older than the one with higher output voltage, +12.113
The explanation will be arranged in the following order. The straight line that connects point Pa or Pl+, where the output voltage 0 point and output current point Ia or output current 111 point intersect, and 03 is called the load straight line, and the straight line that connects point Pa and 0 is called the load straight line, and the line that connects the point Pa and point 0 is called the load straight line, and the point PB If the straight line connecting 0 points is the load straight line B, then the output current! The current difference C between a and the output current 1h.

C-Ib-1a is negative (+: J fluctuation range. Therefore, the slope angle of the load straight line changes depending on the load current value. In Fig. 4, when the load current is the output current 1a, the power supply is unisolated) 01. [Two units of 2 are connected to Iha, and the output current Jb is the old power supply unit, U2゜11
3 shows the case where three units are supplied. The output voltage during the time when the output current increases from zero until the output current reaches 1b is Δ■
(usually about several mV). Error detector 11
If the error voltage detection setting of IJ is not set to absorb the voltage fluctuation width corresponding to this ΔV, the power supply unit U3 will be cut off when only the load is on the load line A, and the load will be on the load line B. Even if the current is increased to , no current is supplied from the power supply unit U3.

However, in the conventional power supply unit 1-, an error detection resistor 9, which is a constant voltage circuit for the output voltage, is used to prevent the output voltage from changing even if the output current changes. Error detection resistor 10. Error detector 11. (Since the output current-output voltage characteristics are made flat by the voltage source 12 and pulse width control circuit 4, etc., when multiple power supply unit groups are operated in parallel, these circuit constants are adjusted to control the output current. Even if you try to balance the power supply unit.

If the voltage setting is off by even a few mV, the balance will shift, making adjustment difficult. Also, even if the settings are successful, input voltage fluctuations and load fluctuations may occur.

This has the disadvantage that the balance may shift again due to changes in the temperature of the parts, changes over time, etc. Furthermore, if multiple power supply units are operated with an imbalance during parallel redundant operation, or if one power supply unit breaks down due to some kind of failure.

Since the current share of each power source unit 1- changes, it causes large transient output fluctuations, and the output voltage cannot follow the output fluctuations, resulting in temporary fluctuations in the output voltage.

(DI) OBJECT OF THE INVENTION The present invention aims to solve the conventional drawbacks of difficulty in adjusting the output current balance and weakness in response to output fluctuations.

(G) Structure of the Invention The purpose of the invention is to perform parallel operation on electronic equipment to supply power (l).
Jli'j multiple power supplies unino l-7! Y, a voltage detection resistor that detects the output voltage of the output circuit of each of the plurality of power supply unit groups, and a voltage detection resistor that detects the voltage detection resistor. Ti
+r− and a reference voltage of a reference voltage source to detect an error voltage, the power supply device includes a detection means for detecting an output current in the output circuit of each of the plurality of power supply unit groups; The output of the means is transferred to the detection voltage IF side of the output voltage detection resistor or the reference voltage side of the reference voltage source, and the error detection circuit i'+ii is operated to lower the output voltage in proportion to the output current. F, and the present invention is configured to control the output of the error detection circuit with the output of the detection means to reduce the output voltage in proportion to the output current.
′, is also achieved.

Immediately, in a power supply device in which a plurality of power supply unit groups are operated in parallel, the output current of the power supply unit is fed back to the error detection circuit for each power supply unit operated in parallel,
By using a power supply unit with output voltage/current characteristics such that the output voltage decreases in proportion to the output current as the output current increases, balance adjustment during parallel operation becomes easier.

The present invention provides a power supply device of a power supply stabilization type, in which the output voltage is stabilized even with output fluctuations, and the output current can also be monitored.

(fl Embodiment of the Invention An embodiment of the present invention will be described below. Fig. 3 shows a diagram of the circuit configuration of one power supply unit according to the present invention. The old Ps has one power supply unit.

13 indicates an output current feedback resistor. Output current feedback resistor 13
Is the DC output side of the error detection resistor 10 the standard? li [source 1
In one example, the two are connected. - The function of receiving AC power from the next assembly source side a, converting it to DC, and supplying DC power to the load from the DC output side, the power protection function of the overcurrent detection circuit 8, etc. are the same as described above, so they will be explained. Saves mB. The output voltage shown in FIG. ,! , IP! It compares the difference with the voltage and sends an error voltage signal 3- to the pulse width control circuit 4 in the direction of lowering the output voltage. Therefore, in contrast to the conventional constant voltage characteristic, which has a flat output voltage characteristic even when the output current increases, we consciously designed the output voltage to decrease in proportion to the output current to make balance adjustment easier. This is what I did. Furthermore, when the output current flowing through the output current feedback resistor 13 decreases, the output detection voltage decreases, and the error detector 11 sends a signal to the pulse width control circuit 4.

Minimum output current value ll that sends out an abnormal decrease signal of output current
It also fulfills the first stage of Ih.

FIG. 4 shows a block diagram of the circuit configuration of the power supply 22 I in another embodiment of the present invention, where I'SU/I? Ii source unit, 14 is a current detection resistor, and 15 is a current detection circuit. When the output current increases, the current detection voltage of the current detection resistor 14 increases, and the pulse width controller 1? 4, an error voltage signal is sent in the direction of decreasing the output voltage. Other functions are the same as those described above, so detailed explanations will be omitted.

FIG. 6 shows an output voltage/current characteristic diagram according to the invention, and shows the output voltage/current characteristics of each power supply unit when three power supply units are operated in parallel. Connect each power supply unit to psol, rs port 2. l's[+3,
As for the output voltage/current characteristics of the old power supply unit PS, as described above, let Ea be the output voltage at the minimum value of the 5 output currents, and let Eb be the output voltage at the output current 1c.

Ea Eh is a solid sloped straight line, and the voltage difference between them is.

The resistance value of the output current feedback resistor 13 is selected and set so that D=Eo-Ef-several tens of mV to several hundred mV. In addition, the power supply unit PSU1 varies from Ea to Ea' at the minimum output current value and from Eb to Hh' at the output current Ic due to adjustment errors in voltage setting and other fluctuation factors. The range between the slope 1'l straight line of the Ea'-Iib' dotted line and the slope straight line of the Ea-Iih solid line is the variation width of the voltage setting. Similarly, power supply unit r'sU2. I'SU
3 also has a voltage setting variation range. The output current Tc takes into account the voltage setting variations of the old power supply unit PS (maximum output voltage Eh') and the power supply unit 1 to PS
between the minimum output voltage Iie' which takes into account the voltage setting variation in the output current Fd of U3.

Even if the voltage setting deviates to the 7h voltage difference of ΔV=Ee' - Eh', the power supply unit PS 113 will not cant off, and the 5 voltage setting will have a margin of 8 V, making adjustment easier.

FIG. 7 shows an output voltage/current characteristic diagram for the load liquid Fat when the circuit is configured according to the present invention. The plurality of power supply units 1- are three as in FIG. 6, and the power supply units PSU1. I'SU2. Since there is some voltage difference between the output voltages of each PSU3, the one with the higher output voltage
5III, PS[12,ll5U3's permission! I will explain them side by side. The output voltage at the minimum output current value of the power supply PS[II is Ea, and the output voltage of the output current Tc is E
b. Power unit.

1-Ps112 output type /M, IC output voltage is Ec,
The output voltage of the output current Id is Ed, and the power supply unit psua
If the output voltage of the output current bl is Re, and the output voltage of the output type mTe is Ef, then the output voltages P and e of the power supply unit 1 to PSU3 and the output voltage Eb of the power supply unit 1 to PSI month are
■ To the voltage difference between.

Δ■ζEe -Eb is the margin for J, Uni, and output voltage adjustment as described above, and each power supply unit l-r'5111. I'S mouth 2. The output current difference between the points where the voltage slope of I'SU3 intersects with the straight line is Δ11°Δ12. If it is Δ■3.

Three power supply units do not cut off even if the load fluctuation is changed to Δ■ of ΔI −Δ■1+Δ124 ΔI3. Even if one power supply unit breaks down due to some kind of failure and the current sharing of each power supply unit changes, there is a margin for the current fluctuation, so the advantage is that the output fluctuation will not be 41 mm. Therefore, it is possible to provide a power supply device of a power supply stabilization type that can improve the drawback of the conventional power supply device being weak against output fluctuations.

Although the embodiment according to the present invention has been described using three power supply units 1-Niso 1-71Y, any number of power supply unit 1- units having the same configuration can perform the same stabilizing unit even if they are operated in parallel. Depending on the number of power supply units, the vertical line of output voltage/current or the output voltage margin may be selected. In addition.

In this embodiment, a method of controlling by detecting the output current has been explained, but it is clear that the same control can be performed using the output of the overcurrent detection circuit on the negative side, although the error will be larger. be.

fgl Effects of the Invention Lido As explained above, in a power supply device in which a plurality of power supply units are operated in parallel, a detection means for detecting an output current is installed in each output circuit of a plurality of power supply units, and the output current can be obtained by this detection means. Is the detected voltage detected on the detection voltage side or base of the output voltage detection resistor? f.

By using the circuit of the present invention that feeds back to the voltage side and operates the error detection circuit, it becomes easy to adjust the voltage settings of each of multiple power supply units, and the output voltage does not fluctuate even if the output fluctuates. First, it has the effect of supplying the load with a stable DC power source that can also monitor the output current.

[Brief explanation of the drawing]

Fig. 1 is a wiring diagram for parallel operation of a power supply device consisting of a group of a plurality of power supply units 1, Fig. 2 is a circuit configuration block diagram of a conventional power supply unit, and Figs. 3 and 4 are a diagram of a power supply unit according to the present invention. Circuit configuration block diagram. FIG. 5 (,) 1 shows an output voltage/current characteristic diagram of a conventional power supply unit, and FIGS. 6 and 7 show output voltage/current characteristic diagrams of a power supply unit according to the present invention. In the drawing!几), I'S[I], PSIJ2.
T'SU3. PSU 4 is a power supply unit I, 3 is a power supply control device, 4 is a pulse width control circuit, 5a and 5h are switching elements, and 6 is a rectifier circuit. 7 is a transformer, 8 is an overcurrent moxibustion output circuit, 9.10 is an error detection resistor, 11 is an error detector, and 12 is a reference voltage source. Reference numeral 13 indicates an output current feedback resistor, 14 indicates a current detection resistor, and 15 indicates a current detection circuit. See 1 Zusho 3 Diagram 4 Zuzu Da Diagram

Claims (1)

[Claims] +11 A plurality of power supply units rIY that perform parallel operation and supply power to electronic devices, and the plurality of power supply units 1 to 1
A voltage detection resistor that detects the output voltage of the output circuit of each group, and a detection voltage of the voltage detection resistor. lI; In a power supply device having an error detection circuit that compares base 1% voltages of voltage sources and detects an error voltage, a detection means for detecting an output current is provided in the output circuit of each of the plurality of power supply unit groups, and the detection means The output of the means is fed back to the detection voltage side of the output voltage detection resistor or the reference voltage side of the reference voltage source, and the error detection circuit is operated to reduce the output voltage in proportion to the output current. Features a power stabilization method. (2) A plurality of power supply unit groups that operate in parallel to supply power to electronic equipment, a voltage detection resistor that detects the output voltage of the output circuit of each of the plurality of power unit 1 groups, and a voltage detection resistor that detects the output voltage of the output circuit of each of the plurality of power unit 1 groups, In a power supply device having an error detection circuit that compares a detection voltage of a detection resistor with a reference voltage of a reference voltage source and detects an error voltage, the output circuit of each of the plurality of power supply unit groups is provided with means for detecting an output current, A power supply stabilization system characterized in that the output of the error detection circuit is controlled by the output of the detection means to reduce the output voltage in proportion to the output current.