JPS5819922A - Direct current power supply device - Google Patents

Abstract

PURPOSE:To improve the use rate of a power supply device, by giving first and second stage setting functions to a dropping current setting circuit and generating electricity stably without increasing the capacity of a DC power supply device even if a device where the input characteristic has a constant power tendency is connected. CONSTITUTION:A dropping current setting circuit 12 is provided with first and second stage dropping current setting functions, and a current value for continuous use rating of a power supply device is set in the first stage, and a current value approximating the maximum allowable in a short time of about 1-2 second is set in the second stage. A switching circuit 13 detects the output of a current detecting circuit 14 and switches the dropping current set to the second stage when the output current of the power supply device is a prescribed value or less and switches the dropping currnet set to the first stage after a delay of about 0.2-2 seconds when the output current of the power supply device becomes higher than the prescribed value. The current detecting circuit 14 is provided for detecting whether a load is connected to the output of the power supply device or not, and a current value or more by which the presence or the absence of the output current of the power supply device is discriminated is set as the prescribed value to the circuit 14.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a DC power supply device such as a switching regulator or a thyristor rectifier, and is aimed at improving the utilization rate of output capacity.

Recently, switching regulators and thyristors 2 IH
Increasingly, a DC-DC converter is connected as a load to an IE device or the like.

Many of these $1 DC-DC converters have the characteristic of a constant power tendency, in which the input wl current increases as the voltage decreases with respect to input voltage fluctuations, and also has a large capacitor in the input circuit. Often connected
Therefore, if this glue load is suddenly connected to the Ii#lEwl original device which is in operation mode, the output of the DC power supply will enter the droop region due to the inrush current flowing into the capacitor, and the output voltage will drop instantaneously. At the same time, since a load current larger than that in a steady state is required, the load may not be able to start stably.

For example, explanation will be made using the output voltage-current characteristic diagram of a conventional DC power supply device shown in FIG. In Figure 1! The broken line shown by is an example of the input voltage-current characteristic required by the load, and is assumed to be at point B during steady operation. When the DC power supply is in no-load operation (point M) at ξ-, when the above-mentioned load is applied, the inrush current of the capacitor causes the point to change instantaneously from point A to point 0. However, at the 0 point, a current exceeding the setting of the drooping current is required as the load WL current, so [current current S+
*The output voltage of the device does not rise above the 0 point, and the load does not start stably.

Such problems can be solved by significantly increasing the output capacity of the DC power supply, but this will reduce the utilization rate of the DC power supply and increase costs. product.

There are many aspects that are unreasonable in terms of electricity consumption, etc.

The present invention has eliminated the above-mentioned drawbacks! It provides a fill device, the droop wll stage setting of the first stage and the @1
A droop current setting circuit having a second stage droop current setting larger than the stage droop 1111'IE setting is provided, and when the output IE current is less than a predetermined value, the second stage droop current setting is applied. The present invention is characterized in that a switching circuit is provided which switches to the one-stage cylinder drooping current setting after a predetermined time delay when 11fi exceeds the predetermined value.

The present invention will be explained below using the drawings.

FIG. 2 is an output voltage-current characteristic diagram of the DC power supply device of the present invention, and FIG. 8 is a diagram of the ii! of the present invention. As an example of a fill source device, a block circuit diagram in the case of a switching regulator is shown.

First, the operation of the DC power supply device of the present invention will be explained using an embodiment of the switching regulator shown in FIG. Generally, a switching regulator receives an AC input 1 and passes it through a nozzle filter 2 to an input rectifying surface l!
8 for rectification and smoothing. Next, the signal is converted into alternating current by the main transistor of the main switching circuit lI4 operated by the output of the drive circuit 9, and is outputted to the output rectifier circuit 6 via the main transformer 5. And again i[f
IIt-ζ converted DC output 8 through output filter
becomes.

Further, the output voltage and current are compared and detected by the constant voltage setting circuit 11 and the drooping current setting circuit 12, and the output voltage and current are compared and detected by the control circuit 10.
As a result, a control signal is output to the drive circuit 9 so that the output has constant voltage and constant current characteristics as shown in FIG.

Thus, in the case of the DC power supply of the present invention, the drooping current setting circuit 12 is provided with a first stage drooping current setting function and a second drooping current setting function, and the first stage drooping current setting is performed using the DC IIE.
The current value is set to be the continuous use rating of the ill device, and the second stage drooping current setting is set to a current value close to the maximum allowable in a short period of about 1 to 2 seconds. For example, if the first stage drooping current film constant is 10 μm, the second stage drooping IIE current setting can be selected to be about 12 to 15 μm. In addition, the switching circuit 18 detects the output of the current detection circuit 14 and determines whether the output current of the 100-current power supply device is Fv? This circuit sets the second drooping WIL flow when it is below a predetermined value (for example, 2 μm), and switches to the drooping current setting for the tube 1 after a delay time of about 0.2 to 2 seconds when it exceeds the predetermined value. . Note that the current detection circuit 14
is provided to detect whether or not a load is connected to the output of the IiI flow power supply, and is directly connected to gwls+.
The predetermined value is set to be at least a current value that allows determining the presence or absence of output current from the device.

Next, the operation of the DC power supply device of the present invention will be explained below using the output voltage-current characteristic diagram shown in FIG. - In Figure 2, the broken line indicated by l is an example of the input voltage-current characteristic required by a load such as a DC-DC converter, and is assumed to be at point B during steady operation.
When the source device is in no-load operation (point A), the output current is less than the predetermined value Is of the current detection circuit, and the setting of the drooping current is switched to the second drooping DC setting I by the switching circuit. . If you turn on the load as described above, the inrush current of the capacitor connected to the input of the load will cause, for example, the second
The drooping current changes instantaneously up to the desired point D. At that time, the willI flowing into the load is under the second drooping current setting, so the capacitor is charged and the output voltage rises again. and the output wlfI
Since l is greater than or equal to the predetermined value Is, after a predetermined time delay, the setting is switched to the drooping current of the cylinder 1, and then changed to the constant voltage region to move to steady operation 111 (point B) GC.

Although the drooping current setting circuit 12 detects the output current, the same effect can be obtained by detecting the primary current of the main transformer 6.

As described above, the DC power supply of the present invention can stably start up without increasing the capacity of the DC power supply even when a DC-DCC converter or any device having a constant power tendency input characteristic is connected as a load. The utilization rate of the DC IIE source device can be greatly improved, and
Its industrial value is enormous in terms of cost, volume, amount of IL, etc.

[Brief explanation of drawings]

Fig. 1 shows an output voltage-current characteristic diagram of a conventional direct FF1ll power supply device, and Fig. 2 shows an output voltage-current characteristic diagram of the device of the present invention. Fig. 8 shows a block circuit showing an embodiment of the present invention. It is a diagram. Fire 1 Inhibition power [* O 7 Diagram seven powers

Claims (1)

[Claims] A drooping current setting circuit having a first stage drooping current #1E setting and a second stage drooping current setting larger than the first stage drooping current setting, and when the output current is below a predetermined value, the second stage The DC power supply device is characterized in that it is provided with a switching circuit that sets a drooping current #lE setting of #1, and switches to a first stage drooping current setting after a predetermined time delay when the output current exceeds the predetermined value.