JP3025971B2 - Vacuum pressure measuring device for pulse current generator and vacuum valve for vacuum circuit breaker - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse current generator, and more particularly, to a pulse current generator suitable for generating a pulse current having a large current and a wide pulse width, and utilizing the device. To a vacuum pressure measuring device for a vacuum valve for a vacuum circuit breaker.

[Conventional technology]

As a pulse current generating device, there is known a device in which a filter circuit is configured by combining a resistor and a capacitor, a DC power supply is connected to the filter circuit, and the output of the filter circuit generates a pulse current by opening and closing a switch. Have been. However, in this method, in order to generate a large square wave pulse current, there is a problem that unless the capacitance of the capacitor is large, the drooping characteristics are deteriorated and a large-capacity switch must be used. .

Therefore, as disclosed in Japanese Patent Application Laid-Open No. 53-73949, there is proposed a filter circuit including a resistor and a capacitor, in which a power supply having excellent drooping characteristics is inserted on the output side. However, even in the case of this method, the capacity of the power supply must be increased in order to generate a pulse current having a large current and a wide pulse width.

On the other hand, SCR Handbook (May 30, 1975, published by Maruzen Co., Ltd., edited by SCR Bandbook Editing Committee), pages 157-15
As described in 8, by using a pulse generation circuit in which a coil and a capacitor are cascaded in multiple stages as a filter element, a pulse current having excellent drooping characteristics can be generated.

[Problems to be solved by the invention]

However, in the above prior art, no consideration is given to the case of generating a pulse current with a large current and a wide pulse width.Even if a pulse generation circuit including an LC filter element is simply used, the pulse width is large with a large current. In order to generate a pulse current, it is difficult to select the inductance of the coil and the capacitance of the capacitor, or it is difficult to make the pulse width variable. Further, a large-capacity switch must be used.

An object of the present invention is to provide a pulse current generator capable of easily selecting a filter element and generating a large current pulse having an arbitrary pulse width, and a vacuum pressure of a vacuum valve for a vacuum circuit breaker using the apparatus. It is to provide a measuring device.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a plurality of pulse generating circuits in which a coil and a capacitor are cascaded in multiple stages as a filter element, and a circuit that connects an output side of each pulse generating circuit to a load. A plurality of switching means, and a switching drive means for opening all the switching means and then closing each switching means in order.The input side of each pulse generation circuit is connected to the DC power supply, and the output side is connected to the DC power supply. Pulses connected to a load via switching means and output from the plurality of pulse generation circuits constitute a pulse current generation device which forms a single pulse as a whole.

Further, the present invention provides an excitation solenoid that receives an excitation pulse to form a magnetic field around a vacuum valve as an object to be measured, an excitation pulse generation circuit that applies the excitation pulse to the excitation solenoid, and a DC high voltage applied to the electrodes of the vacuum valve. A DC high-voltage generation power supply for applying a voltage, an ion current detection circuit for detecting an ion current flowing through the vacuum valve, and an ionizing radiation generator for irradiating the vacuum valve with ionizing radiation. This constitutes a vacuum pressure measuring device for a vacuum valve for a vacuum circuit breaker using a pulse current generating device.

[Action]

Since multiple pulse generation circuits are connected in parallel and pulse signals are generated in order from each pulse generation circuit,
Depending on the number of pulse generation circuits, a large pulse current can be generated and a pulse current having an arbitrary pulse width can be generated. Further, since switching means are provided on the output side of each pulse generation circuit, a large current can flow without using a large-capacity switching means. Further, since the pulse waveform shaping circuit or the reverse voltage generating circuit is provided on the output side of the pulse generating circuit corresponding to the switching means in which the closing operation is performed last, the falling of the pulse current can be made sharp.

〔Example〕

 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, a plurality of pulse generating circuits PG1 to PGn, resistors R1 to Rn, switches SW1 to SWn as switching means, a pulse waveform shaping circuit 14 are provided between a DC power supply 10 and a load 12.
Are arranged, and each of the pulse generation circuits PG1 to PGn is connected to a resistor R1.
To Rn and switches SW1 to SWn are connected in parallel with each other.

In each of the pulse generation circuits PG1 to PGn, capacitors C1 to Cn and coils (inductances) L1 to Ln are cascaded in multiple stages as filter elements, and the input side is connected to a power supply 10 through resistors R1 to Rn.
, And the output side is connected to the load 12 via the switches SW1 to SWn.

Here, in the pulse generation circuits PG1 to PGn, the value of the filter element of each circuit is determined by the current value and pulse width of the pulse current, and the number of each generation circuit is selected.

Further, the switches SW1 to SWn are sequentially closed in accordance with the timing for determining the discharge time by the switching drive means (not shown).

In the above configuration, when the contacts of the switches SW1 to SWn are opened, power from the DC power supply 10 is supplied to the pulse generation circuits PG1 to PGn via the resistors R1 to Rn, and the filter elements of each circuit are charged to the power supply voltage. You. For example, the capacitor C1 is charged via the resistor R1, the capacitor C2 is the resistor R1, the coil
Charged via L1, capacitor Cn is connected to resistor R1, coil L1
LLn to the power supply voltage.

Next, when the switches SW1 to SWn are closed in order to close the contacts in order according to the designated discharge time, pulse currents are generated in order from the pulse generation circuits PG1 to PGn. That is, when the contact of the switch SW1 is closed, the charge stored in each of the capacitors C1 to Cn of the pulse generation circuit PG1 is transferred to the switch SW1.
, And a pulse current is supplied to the load 12 with this discharge. The timing of this discharge is opposite to the charge, and first, the capacitor Cn is discharged via the switch SW1, and subsequently the capacitor Cn-1 is discharged. When the charges of all the capacitors are discharged according to such an order, a pulse current is supplied to the load 12. When SW1 to SWn are closed in accordance with the specified discharge time setting timing, the pulse currents generated from the respective pulse generation circuits PG1 to PGn are superimposed, and a large current and a wide pulse current are applied to the load 12.
Can be supplied to In this case, the switches SW1 to SWn
, Only the current from each of the pulse generation circuits PG1 to PGn flows, so that each of the switches SW1 to SWn can have a small capacity.

Further, in the present embodiment, a pulse waveform shaping circuit 14 is provided on the output side of the switch SWn in which the closing operation is performed lastly, and the pulse waveform shaping circuit 14 causes the output current of the pulse generation circuit PGn to fall. Is performed, the square wave pulse current can be supplied to the load 12.

Next, an embodiment using a thyristor as a switching means will be described with reference to FIG.

In this embodiment, thyristor T1 is used instead of switches SW1 to SWn.
To Tn, a reverse voltage generating circuit 16 having a pulse waveform shaping function is provided in place of the pulse waveform shaping circuit 14, and other configurations are the same as those in FIG.
The same components as those in the drawings are denoted by the same reference numerals, and description thereof will be omitted.

Each thyristor T1 to Tn has a cathode terminal connected to the load 12,
The cathode terminal is connected to the pulse generation circuits PG1 to PGn, and the gate terminal is connected to a firing signal generation circuit (not shown).

In the above configuration, when the ignition signal is not supplied to the gates of the thyristors T1 to Tn, each pulse generation circuit
The output side of PG1 to PGn is shut off, and each pulse generation circuit PG1 to P
The power from the DC power supply 10 is supplied to the Gn filter element, and each capacitor is charged to the power supply voltage.

Next, when firing pulses are sequentially applied to the gates of the thyristors T1 to Tn in accordance with a specified discharge time setting timing, the thyristors T1 to Tn are sequentially turned on. As a result, a pulse current is sequentially generated from each of the pulse generation circuits PG1 to PGn, and the pulse current is supplied to the load 12. The pulse current at this time is a large current and a pulse current having a wide pulse width is supplied to the load 12 as in the case of FIG.

Here, the thyristor T1 conducts and the pulse generation circuit PG1
When the load of each capacitor is discharged, the potential on the anode terminal side of the thyristor T1 decreases. In this state, thyristor T2
When the thyristor T1 conducts, the potential of the anode terminal of the thyristor T1 becomes lower than that of the cathode terminal, a reverse voltage is applied between the anode terminal and the cathode terminal of the thyristor T1 (between input and output), and the thyristor T1 shifts to a cutoff state. . By repeating this operation, the thyristors other than the last thyristor Tn can be switched to the cut-off state without providing a cut-off circuit in each thyristor.

On the other hand, the reverse voltage generating circuit 16 includes a thyristor 18 and a DC power supply.
When a firing pulse is applied from the firing signal generating circuit to the gate of the thyristor 18, the thyristor Tn
A reverse voltage is applied between the anode terminal and the cathode terminal, and the thyristor Tn shifts to the cutoff state. Therefore, if a reverse voltage is applied to the thyristor Tn from the reverse voltage generation circuit 16 after the thyristor Tn is turned on, the thyristor Tn can be shifted to the cutoff state, and the falling of the pulse current supplied to the load 12 is sharp. It is possible to supply a pulse current close to an ideal square wave to the load 12.

Next, an embodiment using the pulse current generator of FIG. 2 as a vacuum pressure measuring device of a vacuum valve for a vacuum circuit breaker will be described with reference to FIGS. 3 and 4. FIG.

In FIG. 3, the vacuum pressure measuring device is a vacuum valve 30.
1, DC high voltage generation power supply 302, excitation solenoid 303, main control circuit 304, ion current detection circuit 305, ion current detection delay circuit 306, excitation pulse generation circuit 307, ionizing radiation generation delay circuit 308, ionizing radiation generator 309 and a shutter 310. An excitation solenoid 303 is arranged around the vacuum valve 301, and a DC high voltage generation power supply 302 is connected to one electrode of the vacuum valve 301, and an ion current detection circuit 305 is connected to the other electrode. An excitation pulse from an excitation pulse generation circuit 307 is applied to the excitation solenoid 303, so that a magnetic field is formed around the vacuum valve 301. The vacuum valve 301 is irradiated with ionizing radiation from an ionizing radiation generator 309 via a shutter 310. As the radiation, for example, γ-rays by ⁶⁰ C0 and X-rays by an X-ray tube are irradiated. An ion current flowing through the vacuum valve 301 is detected by an ion current detection circuit 305. The operation of each circuit is controlled by a control signal from the main control circuit 304.

The excitation pulse generation circuit 307 uses the pulse current generation device shown in FIG.
3, a large current and a wide excitation pulse are applied.

In the above configuration, when the switch of the main control circuit 304 is turned on, the DC high-voltage generation power supply 302 operates, and the vacuum valve 3
At 01, a high voltage is applied as shown in FIG. When this high voltage is saturated, the excitation pulse generation circuit
When the 307 is operated, as shown in FIG. 4B, an excitation pulse having a wide pulse width and a large current is supplied from the excitation pulse generation circuit 307 to the excitation solenoid 303, and a magnetic field is generated from the excitation solenoid 303. . Thereafter, when radiation is irradiated from the ionizing radiation generator 309 to the vacuum valve 301 after a certain delay time τ, an ion current flows through the vacuum valve 301.
The vacuum pressure can be measured by detecting the ion current with the ion current detection circuit 305.

According to the present embodiment, as the excitation pulse generation circuit 307,
By using the pulse signal generator shown in FIG. 2 to supply an excitation pulse having a large current and a wide pulse width to the excitation solenoid 303, the number of turns of the excitation solenoid 303 can be reduced, and the excitation solenoid 303 It is possible to reduce the size and weight. Therefore, it can be configured as a portable device of the vacuum pressure measuring device.

〔The invention's effect〕

As described above, according to the present invention, a pulse is generated in order from a plurality of pulse generation circuits including a coil and a capacitor in a filter element, so that a pulse current having a large current and a variable pulse width is generated. Can be done. Further, a switching device having a small capacity can be used, which can contribute to a reduction in size and weight of the device.

Also, by using a pulse current generator for the excitation pulse generation circuit of the vacuum pressure measuring device, the size of the excitation solenoid can be reduced, and the entire device can be reduced in size and weight.

[Brief description of the drawings]

1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a block diagram showing another embodiment of the present invention, and FIG. 3 is a configuration of a vacuum pressure measuring device using the device shown in FIG. FIG. 4 is a waveform chart of each part of the apparatus shown in FIG. 10 DC power supply, 12 load, 14 pulse shaping circuit, 16 reverse voltage generation circuit, 18 thyristor, 20 DC power supply, R1 to Rn, resistance, RG1 to RGn Pulse generation circuit, T1-Tn thyristor, SW1-SWn numerical value, C1-Cn capacitor, L1-Ln coil.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Shigeru Yamamoto 3-2-1, Sachimachi, Hitachi, Ibaraki Prefecture Within Hitachi Engineering Co., Ltd. (72) Toru Kanazawa 3-2-1, Sachimachi, Hitachi, Ibaraki Prefecture Hitachi Engineering Co., Ltd. (72) Inventor Yoshio Koguchi 1-1-1, Kokubuncho, Hitachi City, Ibaraki Prefecture Inside Kokubu Plant, Hitachi, Ltd. (56) References JP-A-63-69312 (JP, A) 60-68722 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H03K 3/53

Claims (2)

(57) [Claims] A plurality of pulse generating circuits in which a coil and a capacitor are cascaded in multiple stages as a filter element;
A plurality of switching means for respectively opening and closing a circuit connecting the output side of each pulse generation circuit and the load, and a switching drive means for sequentially closing each of the switching means after opening all of the switching means, The input side of the pulse generation circuit is connected to a DC power source, the output side is connected to a load via each switching means, and the pulses output from the plurality of pulse generation circuits form a single pulse as a whole. Current generator. 2. An excitation solenoid for receiving an excitation pulse to form a magnetic field around a vacuum valve as an object to be measured, an excitation pulse generating circuit for applying an excitation pulse to the excitation solenoid, and applying a high DC voltage to electrodes of the vacuum valve. Claims: A DC high voltage generating power supply to be applied, an ion current detecting circuit for detecting an ion current flowing through the vacuum valve, and an ionizing radiation generator for irradiating the vacuum valve with ionizing radiation. A vacuum pressure measuring device for a vacuum valve for a vacuum circuit breaker, comprising the pulse current generating device according to claim 1.