JPH07184321A - Parallel operating system - Google Patents

Abstract

PURPOSE:To burden each power supply equally while keeping balance of power supply to a load, when a plurality of power supplies are operated in parallel, by providing a line for matching the current detection signal between respective power supplies. CONSTITUTION:An input voltage at an input terminal 1 is converted at the voltage converting section 13 in a power supply 10 and fed on a common bus 22 to a load. Output voltage from the voltage converting section 13 is detected 16 in order to detect the output current. Output from a resistor connected with the current detecting section 15 is connected with a control signal terminal 7 and subjected to impedance conversion 20. Outputs from resistors 18, 17 connected with the detecting sections 15, 16 are subjected, along with an output from the impedance converting section 20, to error amplification 21 and fed to a control section 14 for transforming the output voltage from the voltage converting section 13. A voltage is fed to the terminals 2, 3 of power supplies 11, 12 similar to the power supply 10 and power is fed from the output terminals 5, 6 on the common bus 22 to the load and the control signal terminals 8, 9 are connected with the terminal 7. This constitution balances the load between respective power supplies.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parallel operation system for a plurality of power supply devices connected to a single load.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication (Kokai) No. 63-262029 discloses a stabilized DC power supply device for parallel operation. This device connects the current detector output of the power source connected in parallel through a resistor, and the load of the power source connected in parallel with the voltage difference between each detector output terminal based on the connection point of the resistor. It is configured to detect the imbalance of the power supplies and feed back the unbalanced amount to the output voltage control loop of each power supply to control the voltage.

This improvement will be described with reference to FIG.

In the conventional power supply device, as shown in FIG. 2, the voltage input from the input terminals 1, 2, and 3 is converted by the voltage converter 13 and the power is supplied from the output terminal 4 to the load common bus. The voltage detector 16 detects the output voltage and sends it to the controller 14. The control unit 14 controls the voltage conversion unit 1 based on the input signal.
Control 3 Due to the difference in the ambient temperature of the power supply device or the difference in the impedance of the load supply line, when the voltage to be output from the voltage conversion unit 13 is higher than the voltage of the load common bus,
The control unit 14 controls the voltage conversion unit 13 to reduce the output voltage.

When the voltage to be output from the voltage converter 13 is lower than the voltage of the load common bus, the voltage detector 1
6 sees a high voltage on the load common bus, so the control unit 14 does not try to raise the output voltage of the voltage conversion unit 13. Therefore, no power is supplied from the power supply device to the load common bus, and an imbalance occurs with other power supply devices. As a result, the load on other power supply devices increases. If the number of power supply devices that are operated in parallel is large and the above-mentioned phenomenon occurs in a chain, the load is concentrated on a small number of devices, causing destruction.

[0006]

In this conventional parallel operation system, since there is no circuit for balancing the load supply with other power supply devices, there is a difference in output power due to a difference in circulating temperature or the like. Thus, when the number of power supply devices that are operated in parallel is large or the load is large, the load may be concentrated on a small number of the power supply devices, resulting in destruction.

[0007]

A power supply device in a parallel operation system according to the present invention includes a voltage conversion unit for converting an input voltage into an output voltage, a voltage detection unit for detecting an output voltage of the voltage conversion unit, and the voltage conversion unit. A current detection unit that detects the current of the unit,
A first power supply unit for matching the output of the current detection unit with the first power supply unit.
Resistor, an impedance conversion unit for inputting a signal matched by the first resistor, an output of the voltage detection unit provided through the second resistor, and an output provided through the third resistor. An error amplification unit that obtains a difference between the total output of the current detection units and the output of the impedance conversion unit,
The control unit 14 receives the output of the error amplification unit and controls the output voltage of the voltage conversion unit.

[0008]

An embodiment of the present invention will now be described in detail with reference to the drawings.

Referring to FIGS. 1 and 2, one embodiment of the present invention converts an input voltage supplied from an input terminal 1 and outputs an output voltage to a load via an output terminal 4 and a load common bus 22 to a load. The voltage converter 13 to be supplied, the voltage detector 16 for detecting the output voltage of the voltage converter 13, the current detector 15 for detecting the output current of the voltage converter 13, and the output terminal of the current detector 15 A first resistor 19 and a second resistor 18 for matching the output of the current detection unit with the output of another power supply device, and a matched signal of the output of the current detection unit 15 connected to the first resistor 19 Impedance conversion section 20 for inputting and converting the impedance, input provided from the voltage detection section 16 via the third resistor 17,
An error amplifier 21 for inputting an input given from the current detector 15 through the second resistor 18 and an output of the impedance converter 20 and amplifying an error, and a voltage converter for receiving an output of the error amplifier 21. The control unit 14 includes a control unit that controls the output voltage of the unit 13 so as to transform the output voltage.

Next, the operation of one embodiment of the present invention will be described in detail with reference to the drawings.

Referring to FIGS. 1 and 2, the input terminal 1
The voltage input from is converted into an output voltage by the voltage conversion unit 13, and power is supplied from the output terminal 4 to the load (not shown) via the load common bus 22. The voltage detection unit 6 detects the output of the voltage conversion unit 13 and transmits it to the error amplification unit 21 via the second resistor 17. The current detection unit 15 detects the current of the voltage conversion unit 13 and the error amplification unit 21 via the third resistor 18.
Tell to. The impedance conversion unit 20 is connected to another power supply device via the first resistor 19 and the control signal terminal 7 through the output of the current detection unit and receives the divided value as an input to convert the impedance and transmit it to the error amplification unit 21. . Error amplifier 2
The output of 1 is transmitted to the control unit 14 and controls the voltage conversion unit 13. The second and third resistors 17 and 18, the impedance converter 20, and the error amplifier 21 constitute an adder / subtractor circuit, and not only the signal of the voltage detector 16 but also the signal of the current detector and the first resistor The difference between the voltage of the control signal terminal 7 and the voltage of the control signal terminal 7 generated via voltage division with another power supply device is transmitted to the control unit 14 via the error amplification unit 21, and the output voltage of the voltage conversion unit 13 is controlled.

Between the power supplies, the load of the load is balanced, the error amplifier 21 is provided with a third resistor 1
Voltage input via the impedance converter 2
The third resistor 18 and the first resistor 19 are adjusted so that the voltages input via 0 become equal. Due to this adjustment, when a difference occurs in the load on each power supply device due to factors such as the influence of the ambient temperature, the error amplifier 21 uses the output voltage information obtained via the second resistor 17 as the third resistance. Bowl 1
8 and the voltage difference obtained from the impedance converter 20 are adjusted and transmitted to the control unit 14. Based on this, the control unit 14 controls the voltage conversion unit 13 to change the output voltage, and the voltage obtained via the third resistor 18 entering the error amplification unit 21 and the voltage obtained via the impedance converter 20. Try to eliminate the difference between. As a result, the load balance among the power supplies changes. When there is a difference in the circulating temperature between power supply devices and you want to discriminate the load or load, for example, to equalize the load on the internal elements, the output of the voltage detection unit 16 should be effective at the desired load balance. , The second resistor 17, the third resistor 18, and the first resistor 19 may be adjusted.

One of the features of the embodiment of the present invention is that the output voltage V _V of the voltage detection unit 16 is (the output voltage V V
The output voltage V _{A of the V} + current detection unit 15- (voltage V _B of the control signal terminal) is calculated and the result is given to the control unit 14.

Referring to FIG.

[0015]

This equation 3 gives the average current detection level V _B of all the modules. Average current detection level V _B
The difference between the current detection level V _X and its own current detection level V _X is added to the output voltage V _V of the voltage detection unit 16 by the error amplifier 21. Average current detection level V _B is own current detection level V
_{When it is} larger than _X, the output of the error amplifier 21 becomes small,
The control unit 14 controls to increase the output voltage V _V. Average current detection level V _B is own current detection level V _X
When it is smaller, the output of the error amplifier 21 becomes larger,
The control unit 14 controls to reduce the output voltage VV.

When the power supply device 10 is operating alone, the load common bus 22 is open and the average current detection level V _B = the own current detection level V _X. Therefore, only the output voltage VV of the voltage detector 16 is controlled, and this output voltage _VV is stabilized.

When there are a plurality of power supply devices 10, 11 and 12, the voltage of the load common bus 22 becomes the maximum value of the output voltage of the power supply device. This is controlled by the output voltage V _V. Further, each power supply device adjusts the output voltage V _V to the voltage of the load common bus 22 by current feedback, for example, to distribute the current evenly to disperse the heat. Modules with high output voltage are replaced one after another during adjustment. In order to stabilize this, that is, to stop the convergence, a filter may be inserted in the feedback section of E / A in FIG.

In the present invention, the adjustment of the output voltage is mainly performed by the output voltage V _V , and the fine adjustment is performed by the own current detection level V _X or the average current detection level V _B.

[0020]

As described above, according to the present invention, the signal lines for matching the current detection signals are provided between the power supply devices in the parallel operation of the power supply devices. The result is an equal burden on the device.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention.

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

FIG. 3 is a diagram for explaining an embodiment of the present invention applied to a plurality of power supply devices.

FIG. 4 is a block diagram of a conventional example.

[Explanation of symbols]

 1,2,3 Input terminal 4.5.6 Output terminal 7,8,9 Control signal terminal 10,11,12 Power supply device 13 Voltage management part 14 Control part 15 Current detection part 16 Voltage detection part 17 Second resistor 18 Third Resistor 19 First Resistor 20 Impedance Converter 21 Error Amplifier

Claims (2)

[Claims] 1. A voltage converter that converts an input voltage into an output voltage, a voltage detector that detects the output voltage of the voltage converter, and a current detector that detects a current that detects the current of the voltage converter. The first resistor for matching the output of the current detection unit with another power supply device, the impedance conversion unit for inputting the signal matched by the first resistor, and the second resistor provided via the second resistor. An error amplification unit for obtaining a difference between the output voltage of the voltage detection unit and the total value of the output voltage of the current detection unit given through the third resistor and the output of the impedance conversion unit, and an output of this error amplification unit. And a controller 14 that controls the output voltage of the voltage converter based on the parallel operation method. 2. The parallel operation system according to claim 1, wherein the impedance converter, the second and third resistors, and the error amplifier form an adder / subtractor circuit.