JPS60210162A - Dc/dc converter - Google Patents

Abstract

PURPOSE:To immediately specify a defective DC/DC converter by detecting the stop of the operation of the converter by a malfunction detector and transmitting a malunction detection signal. CONSTITUTION:When a shortcircuiting current flows to a switching element 4n, the voltage across a smoothing condenser of an input rectifying and smoothing circuit 1 abruptly decreases. Thus, an input current is supplied from a charging capacitor 16a through a rectifying element 15a to a converter, and continues operating for the prescribed time even after a DC/DC converter 11n stops operating. Then, an output pulse produced from the tertiary winding of a converter malfunction detector of the converters 11a...11n is stopped, the stop of the output pulse is detected by an output pulse detector, and malfunction detection signals are respectively delivered.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a DC-DC converter of a power supply device that connects each load of an electronic device to each of a plurality of DC-DC converters to supply DC power.

(b) Background of the technology Conventionally, the power supply system for power supply devices that supply electronic equipment systems has been designed to reduce the power consumption of power transformers and other peripheral devices due to the increase in power consumption as electronic equipment becomes larger, more sophisticated, and has a higher density. The advantage is that electronic components can be made smaller.

High-frequency switching type DC-DC converter power supply systems, which can easily control the rise and fall of power supply voltage, have been widely put into practical use. This DC-DC converter power supply system.

The input source is a DC power source obtained by rectifying a commercial power source to DC using an input rectifying and smoothing circuit, and this input DC power source is controlled by a control circuit to turn on/off the gate of a switching element, and the DC power source is intermittent and converted into a high-frequency rectangular wave voltage. The switching circuit to be converted and the high frequency rectangular wave voltage from this switching circuit are transformed using a transformer.

A rectifying and smoothing circuit converts it into direct current to obtain a direct current power source.

Some modern electronic equipment systems have many load components that require a high-power DC power supply, so a DC power source obtained by rectifying a commercial power source is used as an input source.

A power supply method is used in which a plurality of DC-DC converters are connected to this common DC input source to supply power, and each DC-DC converter supplies DC power to each load.

(C) Prior Art and Problems This kind of conventional power supply system will be explained. 1st
The figure shows a configuration block diagram of a power supply device that supplies DC power from each of a plurality of DC-DC converters. a is the power input terminal, 1 is the input rectifier and smoothing circuit, 2a--2n are DC
-DC converter, 3a and -3n are loads.

4a is a switching element, 5a is a transformer, 6a is a rectifier and smoothing circuit, 7a is an error amplifier + 8a is a reference power supply +
9a is a pulse width conversion circuit, and 10a is a pulse transformer. The AC power input from the power input terminal a is rectified and smoothed by the input rectifying and smoothing circuit 1 and converted into direct current, which is then supplied to each of the DC-DC converters 2a to 2n as a direct current input source.

Each DC-DC converter 2a-2n intermittently converts the DC input power into a high-frequency rectangular wave voltage, transforms the converted high-frequency rectangular wave voltage with a transformer, rectifies and smoothes it with a rectifier and smoothing circuit, and converts it into a DC power. , supplies DC power to each of the loads 3a and -3n. Each DC-DC converter 2a
-.-2n have the same circuit configuration, so the converter function of one of the DC-DC converters will be explained.

The DC input power input from the input rectifying and smoothing circuit 1 is turned on and off by the switching element 4a, converting the DC input power into a high frequency rectangular wave voltage, which is transmitted to the secondary side through the transformer 5a, and rectified on the secondary side. The smoothing circuit 6a rectifies and smoothes the power, converts it into a DC power source, and outputs the DC power to the load 3a side. The output voltage of the DC power supply supplied to the load 3a side is compared with the reference voltage of the reference power supply 8a by the error amplifier 7a, and the error amount from the reference voltage is inputted from the error amplifier 7a to the pulse width conversion circuit 9a, and the pulse width is A constant voltage circuit is incorporated so that the on/off pulse width of the switching element 4a is controlled by the conversion circuit 9a via the pulse transformer 10a, and the output voltage becomes a specified voltage.

In a power supply device that connects multiple DC-DC converters with the above converter functions and supplies DC power to multiple loads, if the DC-DC converters connected to multiple units due to some kind of failure occur, DC converter 2a-
If one of the converters 2n fails, it is assumed that a short-circuit failure occurs in the switching element 4a of the DC-DC converter 2a. When the primary side of the DC-DC converter 2a is short-circuited, the output of the input rectifying and smoothing circuit 1 decreases, and the outputs of all connected DC-DC converters 2a . . . 2n decrease. As a result, in the conventional method, it is not possible to determine which DC-DC converter has caused the failure, so multiple connected DC-DC converters are disconnected from the input rectifying and smoothing circuit for one - It has the disadvantage that it takes a lot of time to identify the faulty DC-DC converter in order to check whether the DC converter has failed.

(d) Object of the Invention The object of the present invention is to improve the conventional drawback that it takes a lot of time to identify the faulty DC-DC converter.

(e) Structure of the invention The above object is to provide a plurality of DC-DC converters that supply DC power to each load of an electronic device,
In a power supply device equipped with an input rectifying and smoothing circuit that supplies power to a C converter, a first rectifying element is inserted on the ten-pole side of the primary side of each of the plurality of DC-DC converters, and the first rectifying element is A second rectifier element and a third rectifier element connected in series at both ends are connected in parallel, and between the connection point of the second rectifier element and the third rectifier element and one pole side of the primary side. A charging circuit connected to a capacitor with low ripple resistance, and a converter abnormality detection circuit for detecting abnormality in the converter and transmitting an abnormality detection signal on the secondary side of each of the plurality of DC-DC converters, and When a failure occurs in any one of the DC-DC converters, the charging circuit of each of the plurality of DC-DC converters has its own D until the potential drops to a certain potential.
When the C-DC converter continues to operate and the potential of the charging circuit becomes lower than a certain potential and the operation of the DC-DC converter stops, the converter abnormality detection circuit detects each abnormality and sends an abnormality detection signal. This is achieved by the configured present invention.

That is, in a power supply device that connects a plurality of DC-DC converters and supplies input power from an input rectifying and smoothing circuit to supply DC power to each load, the DC-DC converters are connected in series and parallel to the primary side of each DC-DC converter. A charging circuit consisting of three rectifying elements and a capacitor with low ripple resistance, and a converter abnormality detection circuit on the secondary side,
When a failure occurs in the DC converter, the potential of each charging circuit drops below a certain potential and the operation of the DC-DC converter stops, and this stoppage of operation is detected by the converter abnormality detection circuit and an abnormality detection signal is sent. By configuring it to send out data, even if the output voltage of all connected DC-DC converters decreases when any DC-DC converter fails, the converter abnormality detection circuit The operating time is monitored, and the DC-DC converter that was detected to be abnormal first has a fault.
The present invention provides a DC-DC converter in which a faulty DC-DC converter can be identified without disconnecting each converter from the input rectifying and smoothing circuit because it can be determined that the faulty DC-DC converter is a converter.

(f) Example of the Invention An example of the present invention will be described below. FIG. 2 shows a block diagram of a power supply device connected to a plurality of DC-D converters according to the present invention, FIG. 3 shows a normal current diagram flowing through the charging circuit of the present invention, and FIG. 11a and 11a in FIG.
-.lln is a DC-DC converter, 12a is a charging circuit, 13a, 14a, 15a are rectifying elements, 16a is a charging capacitor, 17a is a transformer, 18a is a primary winding 18a
20a is a secondary winding, 21a is an output pulse detection circuit, and 22a is a low voltage detection circuit.

DC-DC] converters 11a--1In have the same circuit configuration, so the DC-DC converter l
I will explain on behalf of la. DC-DC converter lla
In the conventional DC-DC converter, a charging circuit 12a, a transformer 17a having a tertiary winding, an output pulse detection circuit 21a for detecting output pulses from the tertiary winding 20a, or a low voltage detection circuit 22a are added. . Although it is sufficient that either one of the output pulse detection circuit 21a and the low voltage detection circuit 22a is provided, a rain detection circuit is provided here. In the case of only the low voltage detection circuit 22a, the transformer 17a may be a conventional transformer having only primary and secondary windings. The charging circuit 12a receives DC from the input rectifying and smoothing circuit 1.
- A rectifying element 13a is inserted in the input terminal input to the DC converter lla and connected in series to the slave side of the input power supply,
Rectifying element 14a connected in series to both ends of rectifying element 13a
In this circuit, a rectifying element 15a and a rectifying element 15a are connected in parallel, and a charging capacitor 16a is connected between a connection point between the rectifying element 14a and the rectifying element 15a and one pole side of the input power source. As the charging capacitor 16a, a capacitor with a large capacitance value and low ripple resistance is used. The transformer 17a has the primary winding 1
8a.

It is a three-winding transformer having a secondary winding 19a and a tertiary winding 20a.1 Normally, the high frequency rectangular wave voltage from the primary winding 18a side is transformed into %19a@ into the secondary winding, and the secondary winding 19a
DC power is supplied from the side to the load 3a via the rectifying and smoothing circuit 6a. The tertiary winding 20a is a winding that detects output pulses. The output pulse detection circuit 21a has a tertiary winding 20a.
This is a detection circuit that detects the stop of the output pulse when the output pulse from the main unit stops and sends an abnormality detection signal to the outside. Further, the low voltage detection circuit 22a is a detection circuit that detects a drop in the DC voltage output to the load 3a and sends an abnormality detection signal to the outside.

In FIG. 2, the input power from the input rectifying and smoothing circuit '1 is converted from DC to DC by a DC-DC:y inverter lla.

Since the converter function for supplying DC power to the load 3a is the same as described above, it will be omitted, and the function for sending out a converter abnormality detection signal when a failure occurs in any DC-DC converter will be described below. Young.

Multiple DCs are connected due to some kind of failure.
- If one of the -DC converters lla...-11n fails, it is assumed that the switching element 4n of the DC-DC converter llH has a short-circuit failure. DC-DC
When the primary side of converter lln is short-circuited, the output of input rectifying and smoothing circuit 1 decreases, and the outputs of all connected DC-DC converters 1la to 11n decrease. In this case, the current flowing in the charging circuit of each DC-DC converter will be explained in detail with reference to FIGS. 3 and 4. Under normal conditions, as shown in Figure 3.

The forward potential drops of rectifying element 13a, rectifying element 14a, and rectifying element 15a are respectively set to VD13. V.D.
Naturally, if it is 14°VD15.

VD13 < VD14 + VD15, therefore, current is supplied to the converter via the rectifying element 13a, and current i1 flows. The charging current 12 only flows into the charging capacitor 16a when the input rectifying and smoothing circuit 1 is on, and almost no ripple current flows at other times.

Next, the case of abnormality will be explained with reference to FIG.

The rectifier elements of the charging circuit of the DC-DC converter Iln in FIG. 4 are rectifier 13n, rectifier 14n, rectifier 15.
n, the charging capacitor 16n, the primary winding of the transformer is the primary winding 18n, and the switching element is the switching element 4n. When the switching element 4n is short-circuited (marked with ☆), the rectifying element 13n -=-next winding Line 18n→
A short circuit current i3 flows through the switching element 4n.

The voltage across the smoothing capacitor of the input rectifying and smoothing circuit l drops rapidly. Therefore, the DC-DC converter 11a
The rectifying element 13a and the rectifying element 14a on the side are cut off,
Input current is supplied from the charging capacitor 16a to the converter via the rectifying element 15a. The DC-DC converter lla continues to operate until the potential of the charging capacitor 16a drops to a certain potential. Therefore, even after the DC-DC converter lln stops operating, it continues to operate for a certain period of time.

Therefore, each DC-DC converter Ila shown in FIG.
・Tertiary winding 2 which is -11n converter abnormality detection circuit
The output pulse that was being output from 0a...-20n has stopped.

The output pulse detection circuits 21a to 21n detect the stoppage of the output pulse, and each outputs an abnormality detection signal.

Alternatively, the low voltage detection circuits f122a-22n detect a decreased voltage and send an abnormality detection signal from each of them.

By monitoring the operating time of each converter abnormality detection circuit, it can be determined that the DC-DC converter that first sent out the abnormality detection signal has failed. The operating time may be monitored using a known monitoring method. The converter abnormality detection circuit described above was explained using a method in which a pulse detection method using a tertiary winding and an output pulse detection circuit was provided, and a low voltage detection method using a low voltage detection circuit. is achieved. Which method to use may be selected depending on the configuration of the power supply device.

fg) Effects of the Invention As explained in detail above, in a power supply device in which a plurality of DC-DC converters are connected and power is supplied from an input rectifying and smoothing circuit, and DC power is supplied to each load, each pc-DC A charging circuit consisting of three rectifying elements connected in series and parallel to each other and a capacitor with low ripple resistance is installed on the primary side of the converter, and a converter abnormality detection circuit is installed on the secondary side. According to the present invention, the converter abnormality detection circuit detects an abnormality after the potential of each charging circuit drops below a certain potential, and the converter abnormality detection circuit sends an abnormality detection signal. multiple DC-DCs
Even if all the output voltages of the converter drop, the operating time of this converter abnormality detection circuit is monitored, and the DC-DC converter that was detected abnormal first detects the faulty DC.
- It can be determined that it is a DC converter, and a failed DC-DC converter can be immediately identified without disconnecting each unit from the manual rectification and smoothing circuit side, which has the effect of significantly reducing investigation time.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the configuration of a power supply device in which a plurality of conventional DC-DC converters are connected; Fig. 2 is a block diagram of a power supply unit according to the present invention in which a plurality of OC-DC converters are connected; FIG. 4 shows a diagram of the current flowing through the charging circuit of the present invention in a normal state, and FIG. 4 shows a diagram of a current flowing in the charging circuit of the present invention in an abnormal state. In the drawing, ■ is an input rectifying and smoothing circuit, 3a-3n is a load, 4a...-4n is a switching element + 6a is a rectifying and smoothing circuit, 7a is an error amplifier, 8a is a reference power supply,
9a is a pulse width conversion circuit, 10a is a pulse transformer, 1
1a...11n are oc-oc converters, 12
a---12n is a charging circuit. 13 a-43n, 14 a・-44n, 15
a-45n is a rectifier element. 16a and -16n are charging capacitors, and 17a is a transformer. 13 a-48n is the primary winding, 19a is the secondary winding, 20
a indicates a tertiary winding, 21a indicates an output pulse detection circuit, and 22a indicates a low voltage detection circuit. 1st figure

Claims (1)

[Claims] Multiple DCs supplying DC power to each load of electronic equipment
- A power supply device comprising a DC converter and an input rectifying and smoothing circuit that supplies power to the plurality of DC-DC:17 converters, wherein a first rectifier is provided on the ten-pole side of the primary side of each of the plurality of DC-DC converters. a second rectifier element and a third rectifier element connected in series to both ends of the first rectifier element.
a charging circuit in which a rectifying element is connected to a parallel conductor, and a capacitor with low ripple resistance is connected between a connection point between the second rectifying element and the third rectifying element and one pole side of the primary side; A converter abnormality detection circuit that detects abnormality in the converter and sends an abnormality detection signal is provided on the secondary side of each of the plurality of DC-DC converters, and detects a failure in any one of the plurality of DC-11c converters. occurs, until the potential of the charging circuit of each of the plurality of DC-DC converters drops to a certain potential, the DC-DC of each of the plurality of DC-DC converters is
The DC-DC converter continues to operate, and when the potential of the charging circuit becomes lower than a certain potential and the operation of the DC-DC converter stops, each of the converter abnormality detection circuits detects an abnormality and sends an abnormality detection signal. A DC-DC converter characterized by: