JPH0442733A - Power supply - Google Patents

Abstract

PURPOSE:To prevent adverse influence on other DC-DC converter upon fault of DC-DC converter in a power supply by detecting the number of operable DC-DC converter and controlling the output current from the power supply according to thus detected number. CONSTITUTION:Upon fault of any converter module, an alarm signal (ALM1- ALM3) is fed to an alarm signal receiving circuit 23 in a current balance circuit. Consequently, characteristics of the current balance circuit are modified such that the output from an operational amplifier 28 is maximized for an output current from a power supply equal to 2/3 of rated value. When an operational amplifier 29 is operated so that the difference between the outputs from the operational amplifier 28 and from a current balance terminal 26 will be zero, load current can be shared between other power supply within an output current range proportional to the capacity of remaining converter modules.

Description

[Detailed Description of the Invention] [Summary] Regarding a control means for operating a plurality of power supply devices connected in parallel, this D
C, other D-C-D of power supply equipment with DC converter
The purpose of this invention is to prevent overload of the C-DC converter by providing means for controlling the output current of the power supply according to the number of operable C-DC converters in the power supply.

[Industrial Application Field] The present invention connects a small number of DC-DC converter modules in parallel to form a single power supply device, and further connects multiple power supply devices in parallel to supply DC power to a load. Regarding the control method of the supply system, especially the DC-
The present invention relates to a power supply device that can perform balanced operation of output currents according to the capabilities of each power supply device even if any of the DC converter modules fails.

BACKGROUND ART Parallel redundant operation is generally used as a method for increasing the reliability of a power supply device used in an electronic computer called a non-stop computer.

Parallel redundant operation connects multiple power supplies with the same output voltage in parallel to supply power to the load, and even if one of them fails, other normal power supplies can supply the necessary power to the device. This is how it was done. In order to minimize voltage fluctuations in the event of a failure and to reduce the burden on the power supply,
An output current balance circuit is provided for the purpose of averaging the output currents of each power supply device.

Furthermore, each power supply device is configured by connecting DC-DC converter modules in parallel, so that even if - modules fail, output can be supplied by other normal modules.

[Problem that Hatsubaru tries to solve] In the conventional power supply system as described above, when one DC-DC converter module in the power supply units running in parallel fails, the remaining modules are The current balance circuit operates in an attempt to achieve the same output current as other normal power supplies, so the remaining modules in the power supply that include the failed DC-DC converter module must supply a higher output current than normal. did not become.

For example, for a load i that requires a current of 9OA, 3
Consists of 1 converter module with a rated current of 4
When three 5A power supplies are used to supply current, each power supply only needs to output 30A of current, but if one of the converter modules in the power supply fails, that power supply This means that the remaining two converter modules must output 30A.

Therefore, the load on the remaining modules increases, and the temperature rises due to the increase in internal loss, resulting in a decrease in reliability and, in the worst case, damage to the DC-DC converter module.

In view of these conventional problems, the present invention has been developed to provide a system for connecting other DC-DC converters when a DC-DC converter of a power supply device fails.
The purpose is to provide a power supply device that does not adversely affect the converter.

[Means for Solving the Problems] According to the present invention, the above objects are achieved by the means described in the claims.

That is, the present invention provides a power supply device which includes a plurality of DC-DC converters connected in parallel and has a function of controlling the output currents of each power supply device to maintain balance with each other when operating in parallel with other power supply devices. , a power supply device provided with means for detecting the number of operable C-DC converters, and means for controlling the output current of the power supply device according to the number of operable C-DC converters in the power supply device. .

[Function] FIG. 1 is a diagram showing the principle configuration of the present invention, and 1-1
~1 to m are power supply devices, 2-1 to 2-n are DC and DC converter modules, 3 is a current balance circuit, 4 is an output current control circuit, and 5 is operable and detects the number of C-DC converters. In the detection circuit, 6 represents an output current detection section, 7 represents a load, and 8 represents a terminal of a current balance signal.

In the same figure, taking the power supply device 1-1 as an example, the power supply device constantly detects its own output current using the output current detection section 6, and uses this and the input from the current balance terminal to detect its own output current. It operates to supply the load 7 with the current to be borne.

The current is controlled according to the number of operable converter modules built into the power supply device. To explain this control method using one specific example, for example,
When one converter module 2-1 to 2-n are all operable, this is notified to the current balance circuit 3 via the detection circuit 5, and the current balance circuit 3 passes through the output current control circuit 4 to each converter. Module 2-1~2
-n to control the current detected by the output current detection unit 6 to be output up to the rated output of this power supply device.

If one of the converter modules 2-1 to 2-n fails, the detection circuit 5 that detects this will transmit information to that effect to the current balance circuit 3, and the current balance circuit will The output current of the power supply device is controlled to be equal to or less than (n-1)/n of the rated output current.

Furthermore, when two converter modules fail, the output current is controlled to be (n -2)/η of the rated output current.

In other words, when there are n converter modules, if one of them fails, the output current will be equal to (n) of the rated output current.
-i)/n.

[Example] FIG. 2 is a diagram showing an example of the present invention, and 11-1
11-3 is a power supply device, 12-1 to 12-3 are converter modules, 13 is a current balance circuit, 14 is a drive circuit, 15 is an alarm signal line of each converter module,
Reference numeral 16 represents an output current detection section, 17 a load, 18 a terminal for a current balance signal, and 19 a voltage error amplification circuit.

FIG. 3 is a diagram showing details around the current balance circuit in the block diagram shown in FIG. 2, in which 20 is a current detection resistor, 21 is a current detection section, 22 is a current balance circuit, and 23 is an alarm signal. 24 is a reference voltage section, 25 is a voltage error amplifier circuit, 26 is a current balance terminal, 27 to 30 are operational amplifiers, 31 and 32 are transistors, 33
represents an output voltage control section.

The operation of the embodiment will be described below based on FIGS. 2 and 3.

In FIG. 2, each power supply device 11-1 to 11-3 includes three converter modules.

Now, to explain the power supply device 11-1, each converter module 12-1 to 12-3 sends out an alarm signal (ALMI to ALM3) via the alarm signal line 15 when a self-power failure occurs, and the current balance circuit 13 Notify the alarm signal receiving circuit 23.

A when each converter module is operating normally
LM1 to .DELTA.LM3 are each "O", therefore, the points indicated by alphabetical characters A and B in FIG. 3 are both "0", and both transistors 31 and 32 are in an open state.

In this state, the voltage across the current detection resistor 20 becomes an input to the operational amplifier 27, and its output is further input to the operational amplifier 28. At this time, the output of the operational amplifier 28 has the characteristic "when there are three converter modules" shown in FIG. That is, the output of the operational amplifier 28 is adjusted to be maximum when the output current of the power supply device is the rated value 1o. The difference between the output of the operational amplifier 28 and the current balance voltage of another power supply device input from the current balance terminal 26 is input to the operational amplifier 29,
The output of operational amplifier 29 acts on a reference voltage circuit.

For example, if the own current balancing voltage (output of the operational amplifier 28) is lower than the current balancing voltage of the other power supply, the output of the operational amplifier 29 becomes high, which increases the voltage at the 0 point of the reference voltage circuit, so the voltage The control output of the error amplifier circuit operates to increase the output current of the power supply. This operation continues until the output of the operational amplifier 28 and the current balance voltage of the other power supplies input to the current balance terminal become equal, and the voltage across the resistor R becomes approximately Ov. As a result, the output current of each power supply are equalized.

Now, if one of the converter modules fails, one of the signals from ALMI to ALM3 becomes "l", which causes the signal at point A to become "l". Therefore, the transistor 31 is turned on, and the output of the operational amplifier 28 has the characteristic "when two converter modules are used" in FIG. 4.

That is, the characteristics of the current balance circuit change so that the output of the operational amplifier 28 becomes maximum when the pressure current of the power supply device is 2/3 of the rated I0.

By operating the operational amplifier 29 so that the difference between the output of the operational amplifier 28 having this characteristic and the current balance terminal 26 is eliminated, the power supply device in which one converter module has failed is reduced to the number of remaining converter modules (2 units).
The current to the load can be shared with other power supplies within the range of output current (2/3 I.) proportional to the capacity of the power supply.

If two converter modules fail, point A will be “
O”8 points become “1” and transistor 31 turns off 32
is turned on, and the output of the operational amplifier 28 has the characteristic "when one converter module is used" in FIG. 4. That is, the characteristics of the current balance circuit change so that the output of the operational amplifier 28 is maximized when the output current of the power supply is 1/3 of the rated value, similar to when one unit fails as described above.

Therefore, the failed power supply can share the current to the load with other power supplies within the range of output current (1/3 I.) proportional to the capacity of one remaining converter module.

That is, in this embodiment, three DC-DC converter modules are connected in parallel so that these three modules can output the rated current as a power supply device. When a plurality of such power supply devices are operated in parallel to supply power to a load, the current balance circuit of each power supply device operates so that the output current of each power supply device is averaged.

The current balance circuit consists of an output current detection section 16 that generates a voltage proportional to the output current of each power supply device, and a circuit that amplifies the voltage and changes the reference voltage of the output voltage control section 23. The characteristics of the current detecting section 21 (the relationship between the output current and the generated voltage) are changed according to the number of converter modules as shown in Fig. 4, so that optimal output current balance operation can be performed. . In this embodiment, the current detection unit 21
This is done by varying the amplification factor of the operational amplifier 28.

As a result of the above, for example, if three power supplies with a rating of 45A are used to supply current to a 9OA load as described above, even if - converter modules fail, each power supply has Depending on the number of normal converter modules, it is sufficient to output a current of 22.5 A for two failed converters and 33°75 A for three normal converter modules, so the load on the converter modules is not too large, so conventional Problems like this will disappear.

[Effect of power supply] As explained above, according to the present invention, in a power supply unit configured by connecting a plurality of power supply devices each having a plurality of DC/DC converters connected, the number of operable converters can be increased. Since the output of each power supply device can be controlled accordingly, if a converter breaks down, there is no possibility that an excessive load will be applied to other converters in the power supply device that includes the converter, resulting in loss of reliability.
This has the advantage of being able to prevent damage to the structure.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the principle configuration of the present invention, Fig. 2 is a diagram showing an embodiment of the invention, Fig. 3 is a diagram showing details around the current balance circuit of the embodiment, and Fig. 4 is a diagram showing the current balance circuit of the embodiment. FIG. 3 is a diagram showing characteristics of a balance circuit.

Claims (1)

[Scope of Claims] A power supply device comprising a plurality of DC-DC converters connected in parallel and having a function of controlling the output currents of each power supply device to maintain balance with each other when operating in parallel with other power supply devices. , comprising means for detecting the number of operable DC-DC converters, and means for controlling the output current of the power supply according to the number of operable DC-DC converters in the power supply. power supply.