JPS5851734A - Device for protecting power source - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a protection device for a power supply device that allows a DC power supply device to experience overvoltage reliably.

The first vA is an example of a conventional owisiw source installation equipped with a storage device.
is a rectifier transformer and a 2nd company DC converter, and the DC voltage is supplied to the load resistor through a capacitor Jl as a DC filter and a switch 4. Further, 6 and 7 are a cyrisk and a discharge resistor, respectively, as eel protection devices. Note that the illustration and explanation of the control circuit are omitted.

In the DC power supply device configured in this manner, when the switch 4 is released to interrupt the load current, an overvoltage exceeding the rated voltage is generated due to the inductance floating in the circuit. Further, when an impulse generated in the AC system during no-load operation is rectified by the DC exchanger 2, the DC voltage may increase. These overpressures occur when the equipment is operated with no load, but they are caused by
The voltage increases and remains at 9. And -
If the voltage of the blind capacitor S increases, it cannot be controlled by the DC converter 2. On the other hand, in a relatively low-voltage DC power supply, an overvoltage like #i-jin does not occur for a long time, but in a IIIK high-voltage DC power supply, it not only causes damage to the insulation of various parts, but also
It is desirable to keep rounding as low as possible, which requires increases in the ratings of various equipment.

Therefore, conventionally, when an overvoltage as described above occurs,
The thyristor 6, which is a protective device, is made conductive and the charge in the capacitor 3 is discharged by the discharge resistor 1, so that the terminal voltage of the capacitor 3 is lowered. However, in this case, once the thyristor 6 is made conductive, the current in the DC converter 2 also flows, so it is necessary to interrupt the AC system or stop the operation of the DC converter 2, and the power supply must be stopped. The disadvantage is that it does not.

The present invention has been made to solve the above-mentioned drawbacks, and its purpose is to protect the power supply device so that the overvoltage tube can be suppressed without stopping the power supply device from rolling over to zero, so that the device can be used reliably. -Providing equipment tubes.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 2 shows an example of the configuration of a DC power supply device equipped with the protection device 1 according to the present invention, and the same parts as in FIG. 1 are designated by the same reference numerals.

In the figure, 1 is a rectifier transformer, 2 is a DC converter that converts the output of the rectifier transformer 1 into DC, and the DC voltage is supplied to a load resistor 5 via a gold switch 4. Further, 12 and 1 are first and second capacitors as DC filters connected in series with each other, and are connected to the output terminal of the DC converter 2. Reference numerals 13 and 9 denote first and second voltage dividing resistors connected in series with each other, and connected in parallel with each of the capacitors 12 and 8. Furthermore, 6 is a thyristor as a switching element, and 10 is a reactor, which are connected in series with each other and in parallel with the second capacitor 1 to form an LC oscillation circuit. In addition, as stated above, the combined capacitance of 1111 and the second capacitors 12 and 8 is:
The capacitance should be made equivalent to the capacitance of the capacitor 3 shown in FIG.

In such a configuration, the first and! 12 capacitors 1
2 and 18 are charged by sharing the DC converter jO[m voltage. The load current can be interrupted by the switch 4], and if the impulse p4 of the AC system is rectified and the DC voltage increases, the thyristor is made conductive. Then, from K, an 0L-Cil dynamic circuit is formed with the capacitor 8 of '1jE2 and the reactor 10, and when the voltage of the 20th:1 capacitor 8 is reversed, the thyristor ε is rendered non-conducting. In this case, the capacitor 12 of the DC power supply 1
, and the voltage of the second capacitor 1, and after the thyristor 6 is turned on, the voltage of the second capacitor 8 becomes negative, so that the voltage increases and the voltage of the second capacitor 1 can be decreased.

First, it is also possible to select appropriate values for the voltage division ratios of the first and second capacitors 12 and 8 (thereby adjusting the down-conductor voltage of the DC voltage. After the voltage of IJ is reversed and discharged, it is gradually charged by the first and second voltage dividing resistors IJ and 9 and enters a steady state.

In this way, the 91st IflTh and the 20th
The capacitor voltage is reversed by condensers 12 and 8, reactor 10, and 0L-C vibration.

~ By lowering the DC voltage tube, it is possible to adjust the voltage drop without stopping the DC power supply, suppress overvoltage that occurs during no-load operation, and securely protect the DC and current power supply. You can have rice cakes.

It should be noted that the present invention is not limited to the above embodiments, but can also be implemented as follows. , .

(1) FIG. 3 shows the configuration of another embodiment of the present invention. In other words, in this configuration, the L-C vibration adjustment resistor 11
By adjusting the resistance value of the second capacitor 8
The 0 reversal voltage can be varied and the DC voltage can be reduced by 7 ty.
(2) In the above embodiment, the capacitor used as the DC filter was composed of two capacitors, 12 and 8.
However, the present invention is not limited to this, and it is also possible to configure the structure by connecting three or more II capacitors in series.

In addition, the present invention can be implemented with various modifications within the scope of the invention by changing its gist.

As explained above, according to the present invention, a highly reliable power supply device is provided which can suppress overvoltage and reliably maintain lIc1I without stopping the operation of the power supply device and while making it possible to adjust the voltage drop. Protective equipment can be provided.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a conventional DC power supply device, and FIGS. 2 and 3 are schematic configuration diagrams showing one embodiment and other embodiments of the present invention. 1... Rectifier transformer, 2-direct cage converter, 3゜8.1
2...Capacitor, 4...Switch, 1...Load resistance, 6...Thyristor, r, 9.11-Resistance, JO
・・・Reactor, 11-・Resistor.

Claims (1)

[Claims] In a power supply device that supplies the DC voltage of a DC converter to a load via a container serving as a DC filter, the capacitor tt* is composed of several series capacitors, and is connected in parallel with a predetermined capacitor among them. A series circuit of a switching element and an impedance is connected, and when the DC voltage rises, the switching element operates to form an oscillating circuit between the impedance and the impedance. .