JPH0748341B2 - Vacuum pressure measuring device for vacuum valve for vacuum circuit breaker - Google Patents

Description

The present invention relates to a vacuum pressure measuring device for a vacuum valve for a vacuum circuit breaker.

[Conventional technology]

Since the internal vacuum pressure of conventional vacuum valves is measured with a single vacuum valve before shipment from the factory, the solenoid coil surrounding the vacuum pressure vessel to be measured has several hundred or more turns to increase the excitation magnetic flux density. , The power supply capacity was not increased too much. Alternatively, in order to suppress the degassing effect in the vacuum container due to the vacuum pressure measurement, there is a method in which a direct current high voltage applied between the electrodes is pulsed by a thyratron or the like.
In addition, as disclosed in Japanese Utility Model Publication No. 54-30975, the solenoid coil surrounding the vacuum container to be measured is doubled or more to expand the measurement range of the vacuum pressure, or disclosed in Japanese Patent Laid-Open No. 86-50.
As shown in No. 4, the range of vacuum pressure measurement was expanded by utilizing the precursory discharge by ionizing radiation.

On the other hand, for measuring the vacuum pressure of the vacuum valve mounted on the vacuum circuit breaker, a method of installing a magnetron element on the end plate of the vacuum valve was considered, but the cost of the vacuum circuit breaker is high because the magnetron element is expensive. It has not been realized because it becomes a factor of. Further, there is a simple method that detects deterioration of the vacuum pressure from the capacitance change between the lines of the vacuum circuit breaker, but the accuracy is poor and it is not often used.

In order to provide stable and high-quality power supply in the recent highly developed information society, the vacuum circuit breaker, which is the backbone of power transmission and distribution, is required to have high reliability. For that purpose, attention has been paid to the prediction of the service life of the vacuum valve, which is the vital part of the vacuum circuit breaker, that is, the prediction of vacuum pressure changes. However, as described above, the measuring method in the state of being mounted on the vacuum circuit breaker has not been established. In addition, the vacuum pressure measurement method for a single vacuum valve is used for measuring the vacuum pressure of the vacuum circuit breaker used in the field because the coil surrounding the container to be measured is large and the power supply equipment is large. Not not.

Currently, the most used method is a DC withstanding voltage method using a DC high voltage generator. However, this method is effective as a vacuum degree checker in the glow discharge region where the internal vacuum pressure is 3 × 10 ^-2 Torr or higher, but the value below the guaranteed value of the vacuum valve, 5 × 10 ^-4 Torr, is measured. Can not. The internal vacuum pressure during operation of the vacuum valve is 1 × 10 ^-6 Torr to 1
Since it is in the range of × 10 ^-4 Torr, it is necessary to grasp the above range as an absolute value in order to predict the life of the vacuum valve.

[Problems to be Solved by the Invention]

In the above prior art, the internal vacuum pressure of the vacuum valve mounted on the vacuum circuit breaker cannot be measured as an absolute value, so that the life of the vacuum valve cannot be predicted.

The present invention has been made in view of the above points, and measures the vacuum pressure of a vacuum valve for a vacuum circuit breaker, which makes it possible to easily predict the life of the vacuum valve mounted in the vacuum circuit breaker, and to facilitate transportation and installation. The purpose is to provide a device.

[Means for Solving the Problems]

The above object is achieved by controlling the rising time constant of the pulse current of the large current pulse current to 0.1 to 5 mS.

A vacuum valve mounted on a vacuum container to be measured (vacuum valve) was surrounded, and a solenoid coil for exciting a magnetic field was formed so as to be attachable to the vacuum valve (1 to 50 turns).

The high-current pulse power supply, the control circuit, and the detection circuit are formed so as to be divided into a plurality of parts and to be portable.

[Action]

Since the above-mentioned means is provided, the probability of generation of ion current is increased, and the vacuum pressure measurement range can be expanded to 10 ^-7 Torr.

Further, the solenoid coil can be freely mounted on the vacuum valve mounted on the vacuum circuit breaker, and the large-current pulse power supply, the control circuit, and the detection circuit can be respectively divided into a plurality of parts.

〔Example〕

Hereinafter, the present invention will be described based on the illustrated embodiments. One embodiment of the present invention is shown in FIGS.
The vacuum pressure measuring device 2 of the vacuum valve 1 for the vacuum circuit breaker has a high voltage applied to the vacuum valve 1 mounted on the vacuum circuit breaker 3 and the detachable electrodes 4 and 5 sealed inside the vacuum valve 1. DC high-voltage power supply 6 for applying
A control circuit 7 that maintains a delay time until the high voltage applied to 5 reaches a predetermined voltage, a high-current pulse power supply 8 that operates via this control circuit 7, and a magnetic field is generated by the output of this pulse power supply 8. And a solenoid coil 9 arranged so as to surround the vacuum valve 1. The peak value and integrated value of the ion current flowing between the pair of electrodes 4 and 5 are measured by the detection circuit (ion current detector) 10 to measure the vacuum pressure in the vacuum valve 1. In the vacuum pressure measuring device 2 configured as described above, the high-current pulse power source 8 is used in this embodiment.
The rise time constant of the pulse current was controlled to 0.1 to 5 mS. By doing so, the probability of generation of the ion current becomes high, and the vacuum pressure measurement range can be expanded to 10 ^-7 Torr, and the life prediction of the vacuum valve 1 mounted on the vacuum circuit breaker 3 and It is possible to obtain the vacuum pressure measuring device 2 of the vacuum valve 1 for the vacuum circuit breaker, which can be easily transported and attached.

That is, as shown in FIG. 1, the vacuum valve 1 is mounted on the vacuum circuit breaker 3. An opening / closing operation command of the vacuum valve 1 from the vacuum circuit breaker 3 is transmitted from an insulating operation rod 11. The vacuum valve 1 is kept airtight by an insulating cylinder 12, upper and lower end plates and a bellows 13. Connection to the closed switchboard is made via external terminals 14 and 15.

To measure the vacuum pressure in the state shown in FIG. 1, the solenoid coil 9 is attached to the vacuum valve 1. At this time, since the vacuum valve 1 is fixed to an insulator or a molded insulating cover (neither is shown), the solenoid coil 9
Is not easy to install. Therefore, the number of turns of the solenoid coil 9 is in the range of 50 to 1 in consideration of the space between the insulator or the insulating cover and the vacuum valve 1 and the space between the phases.

The vacuum pressure measuring device 2 includes a DC high voltage power supply 6, a large current pulse power supply 8, a detection circuit 10, and a ground switch 1 for grounding the DC high voltage.
6 and a grounding resistance 17, a power supply 6 and a control circuit 7 for controlling the equipment and having an indicator for displaying the ion current.

The high-current pulse power supply 8 has a circuit configuration shown in FIG. 8a is a power supply, 8b, 8l, 8o are limiting resistors, and 8c, 8m, 8p are pulse generating circuits. Each pulse generation circuit 8c, 8m, 8p is composed of reactance and capacitance. The pulse generation circuit 8c is composed of reactances 8e, 8g, 8j and capacitors 8d, 8f, 8h, 8i. The other pulse generating circuits 8m and 8p have the same basic configuration as the pulse generating circuit 8c. The chain line in the pulse generating circuit shown in the figure is for allowing an arbitrary combination of inductance and capacitance to form an exciting current waveform described later.
In addition, the fact that the pulse generation circuits 8c, 8m, and 8p are connected by a chain line also shows that they can be arbitrarily connected in parallel. The discharge switches 8k, 8n, 8n,
8q was installed, and the pulse generation circuit 8p at the final stage was equipped with a pulse waveform shaper 8r. Then, the solenoid coil 9 is connected to the output end of this high-current pulse power supply.

The operation of this high-current pulse power supply will be described below. Power supply 8a
Through each limiting resistor 8b, 8l, 8o, each pulse generator circuit 8c, 8m,
8p capacitance (eg 8d, 8f, 8h, 8i for generator 8c)
Will be charged. Discharging switch 8k, 8 when charging is completed
When n and 8q are turned on with a time delay, the pulse generator circuit 8
A current waveform in which c, 8m, and 8p are superimposed can be formed.
The pulse wave shaper 8r at the final stage shapes the wave tail of the pulse current waveform.

FIG. 3 shows a simple time chart of the vacuum pressure measuring device. It is premised that the high-current pulse power source 8 (see FIG. 1) is already in the charging completed state. In the figure, A is a DC high voltage, B is a pulse excitation current, and C is an ion current. First, when the switch of the DC high voltage power supply 6 (see FIG. 1) is turned on, there is a time delay of T ₁ until the DC high voltage reaches a predetermined voltage. After reaching T ₁ , the discharge switch of the pulse power source 8 (see FIG. 1) is turned on after T ₃ , and the pulse current B is supplied. The ionic current C is generated with a slight time delay. At this time, the DC high voltage A maintains the predetermined voltage for T ₂ seconds. Also, the pulse current B must be maintained for T ₅ seconds.

FIG. 4 is a diagram in which the waveform of the pulse current B is modeled. The time constant τ that reaches 63% of the peak value is determined by the circuit constant and the reactance of the solenoid coil 9 (see FIG. 1). W ₁ is a waveform of only the pulse generating circuit 8c (see FIG. 2), and W ₂ is a waveform in which the pulse generating circuits 8m and 8p (see FIG. 2) are superimposed. T ₄ shows the time of the current h ₅₀ of 50% of the peak value.

FIG. 5 shows the relationship between the vacuum pressure and the ion current formation time t. The ion current formation time means the voltage is applied between the electrodes of the vacuum valve 1 (see FIG. 1), and the pulse current of the solenoid coil 9 (both see FIG. 1) surrounding the vacuum valve 1 is passed to be excited. It is the time from the moment when the gas molecules in the vacuum valve are ionized and an ionic current is formed.
Since the ion current cannot be detected unless the ion current is formed, it is necessary to maintain the pulse current h ₅₀ (see FIG. 4) until the ion current is formed.
The straight line a in the same figure shows the ionization time in the conventional method in which the number of turns of the solenoid coil 9 (see FIG. 1) is several thousand. The straight line b shows the ionization current formation time. The straight line c is the ionization time when the number of turns of the solenoid coil 9 (see FIG. 1) is 50 or less and the rising time constant τ (see FIGS. 3 and 4) of the pulse current is 5 mS or less, d
Is the ionization current formation time at that time. Vacuum pressure P is
10 ^-6 when Torr is h ₅₀ of T ₄ hours (see FIG. 4) has been shown to be required 10 mS. When the lower limit of vacuum pressure measurement is expanded, for example, when P = 10 ⁻⁸ Torr, the ionization current formation time d becomes 1 S, the pulse generation circuit becomes several tens of stages, and the power supply becomes huge. The present invention provides a device that can be used in the field, so that the range of vacuum pressure measurement is 10 ^-6.
As long as it is equal to or higher than Torr, T ₄ (see FIG. 4) should last about 50 mS.

FIG. 6 shows the ampere-turn (AT) of the magnetic field excited by the solenoid coil 9 (see FIG. 1) and the range of vacuum pressure at which the ion current can be detected. The diagonal lines on the upper right of the curves e, f, g, and h indicate that the ion current can be detected at that portion. The curves e, f, g, and h represent the envelope of the lower limit value of the ion current detection when the solenoid coil 9 (see FIG. 1) has 3, 30, 300, and 3000 turns and the exciting current is passed. However, instead of supplying the same current to each solenoid coil, the excitation current source shown in Table 1 was used. That is, 3000 turns and 300 turns carry a constant DC current,
For the windings and 3 windings, the pulse current shown in FIG. 4 was applied. FIG. 6 shows that, in the case of the same magnetic field, the faster the rise time constant of the exciting current, the wider the detection range of the vacuum pressure. Table 1 shows the lower limit of measurement of solenoid coil, exciting current source, vacuum pressure when the magnetic field is 30,000 A · T,
Shown here are the results of examination of the possibility of measurement at the yield. As shown in the table, solenoid coil 3,000 turns, 300
The winding cannot be mounted on a vacuum valve mounted on a vacuum circuit breaker. Volumes 30 and 3 can be attached to a vacuum valve, but the pulse power supply becomes large-scale. Therefore, it is important to select the lower limit of vacuum pressure and the T ₄ seconds of h ₅₀ shown in Fig. ₄ to determine the appropriate power source size.

That is, if the number of turns of the solenoid coil is reduced and the rise time constant τ of the pulse current of the high current pulse power supply is set to 0.1 to 5 mS, the vacuum pressure measurement range can be increased. It can be expanded to 10 ^-7 Torr, and the vacuum pressure of the vacuum valve mounted on the vacuum circuit breaker can be measured. In this way, the vacuum pressure is set to the lower side to measure the ion current, and the solenoid coil is made smaller so that it can be attached to the vacuum valve mounted on the vacuum circuit breaker.
The device for measuring the ionic current was downsized to achieve the intended purpose.

However, the DC high voltage power supply, the large current pulse power supply, the detection circuit, and the control circuit cannot be transported together. Therefore, it is necessary to divide each so that they can be transported. Although it is easy to carry the DC high voltage power source independently, it is basically desirable that the high current pulse power source and the control circuit have an integral structure. In particular, in a high-current pulse power supply, a large current is pulsed in the energization path, so it is necessary to take measures to suppress electromagnetic repulsion and heat generation due to connection.

FIG. 7 shows a state in which the large current pulse power supply and the control circuit are separated. Control circuit box 18 at the top, first stage large current pulse generation circuit box 8c 'at the second stage, second stage large current pulse generation circuit box 8m' at the third stage, and Nth stage large current pulse generation at the bottom Circuit box
Place 8p '. Wheels 19 are provided under each box 18, 8c ', 8m', 8p 'for easy transportation. Box 8 below the second level
A wheel bag 20 is provided on the upper part of c ′, 8m ′, 8p ′, and is used as a guide and fixing when a box is loaded from above. Further, a lever 21 is provided on the front surface of the upper portion, and a connecting portion protective cover (protective lid) 22 is provided on the rear surface of the upper portion. In the figure, 31 is a handle. Next, automatic connection of conductors will be described with reference to FIGS. 7 and 8.

A plurality of capacitors 23 and reactances are arranged and connected to the Nth high-current pulse generator circuit box 8p 'at the bottom. In order to connect to another box 8m ', the connecting portion 26 such as a chuck contact is attached to the tip of the conductor 24 that holds the conductor 24 with the insulator 25.
To place. On the upper part of the connecting part 26, a connecting part protective cover
22 is provided, the wire 28 is connected to the cover return spring 27, and one end of the connecting portion protection cover 22 is also connected to the wire 28. Wire 28
Is connected to lever 21 via guide pin 29,
One end of 21 is hinged. The second-stage high-current pulse generation circuit box 8m 'has a similar structure, but the bar 30
And the bar 30 is longer than the lower tip of the conductor 24.

When the second stage high current pulse generation circuit box 8m 'is loaded on the Nth stage high current pulse generation circuit box 8p' from above,
19 is guided by the wheel bag 20. When the wheel 19 is guided by the wheel bag 20, the bar 30 hits the lever 21, and when pulling the wire 28 to the left, the connecting portion protection cover 22 connected to the wire 28 slides to the left. When the connecting portion protection cover 22 also slides to the left, the conductor 24 is inserted and inserted into the connecting portion 26, so that automatic connection is established. When separating in the opposite, lift the second stage high current pulse generation circuit box 8m '
With the cover return spring 27, the connection protection cover 22 and the lever 21
It is possible to prevent the foreign matter and dust from entering the connecting portion 26 by returning the and to their original positions.

As described above, according to this embodiment, the following effects can be obtained.

(1) A vacuum valve mounted on a vacuum circuit breaker can be equipped with a solenoid coil to grasp the vacuum pressure as an absolute value.

(2) Therefore, it is possible to predict the life of the internal vacuum pressure of the vacuum valve by regularly measuring, and it is possible to improve the reliability of the vacuum circuit breaker.

(3) Since this device is divided and made portable, it can be used for all fields.

〔The invention's effect〕

INDUSTRIAL APPLICABILITY As described above, the present invention facilitates the life prediction, transportation and installation of the vacuum valve mounted on the vacuum circuit breaker, and the life prediction, transportation and mounting of the vacuum valve mounted on the vacuum circuit breaker. It is possible to obtain a vacuum pressure measuring device for a vacuum valve for a vacuum circuit breaker that can be easily made.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a circuit configuration of an embodiment of a vacuum pressure measuring device for a vacuum valve for a vacuum circuit breaker of the present invention, FIG. 2 is a circuit diagram of a large current pulse power supply of the same embodiment, and FIG. Similarly, a time chart of one embodiment, FIG. 4 is a pulse current waveform diagram of the same embodiment, and FIG. 5 is a characteristic diagram showing a relationship between vacuum pressure and ion current formation time of the same embodiment, FIG. Is a characteristic diagram showing a vacuum pressure range in which an ion current can be detected by magnetic field strength of one embodiment, and FIG. 7 is a perspective view showing a state in which a large current pulse power supply and a control circuit of one embodiment are divided. The figure is also a vertical side view showing a state in which the divided pulse generating circuit boxes of one embodiment are automatically connected. 1 ... Vacuum valve (measurement vacuum container), 2 ... vacuum pressure measuring device, 3 ... vacuum circuit breaker, 4,5 ... electrode, 6 ... DC high voltage power supply, 7 ... control circuit, 8 ... large current pulse power supply, 8c ′… First
8th stage high current pulse generator circuit box, 8m '... 2nd stage high current pulse generator circuit box, 8p' ... Nth stage high current pulse generator circuit box, 9
… Solenoid coil, 10… Detection circuit, 22… Coupling part protective cover (protective lid), 26… Coupling part.

Claims (7)

[Claims] 1. A vacuum container to be measured mounted on a vacuum circuit breaker, a DC high-voltage power supply for applying a high voltage to a freely separable electrode hermetically sealed in the vacuum container to be measured, and this power supply. From the control circuit for maintaining a delay time until the high voltage applied to the electrode reaches a predetermined voltage, a high-current pulse power source that operates via this control circuit, and a magnetic field is generated by the output of this pulse power source, And a solenoid coil disposed so as to surround the vacuum container to be measured, and the peak value and integrated value of the ion current flowing between the pair of electrodes are measured by a detection circuit to measure the vacuum pressure in the vacuum container to be measured. In a vacuum pressure measuring device for a vacuum valve for a vacuum circuit breaker for measuring, the vacuum time for a vacuum valve for a vacuum circuit breaker, characterized in that the rising time constant of the pulse current of the large current pulse power supply is controlled to 0.1 to 5 mS. Force measuring device. 2. The high-current pulse power supply has a waveform with a peak value of 1,000 A to 10,000 A for a large-current pulse, and a waveform shaping for maintaining a current-carrying width of 10 to 50 mS from the rise to 50% of the peak value. The vacuum pressure measuring device for a vacuum valve for a vacuum circuit breaker according to claim 1, which has a function. 3. The vacuum pressure measuring device for a vacuum valve for a vacuum circuit breaker according to claim 1, wherein the solenoid coil is formed so as to be attachable to a vacuum container to be measured mounted on the vacuum circuit breaker. 4. The vacuum pressure measuring device for a vacuum valve for a vacuum circuit breaker according to claim 1, wherein the solenoid coil has 1 to 50 turns. 5. The vacuum pressure of a vacuum valve for a vacuum circuit breaker according to claim 1, wherein the high-current pulse power supply, the control circuit, and the detection circuit are formed so as to be divided into a plurality of parts and to be portable. measuring device. 6. The large-current pulse power source is housed in a plurality of large-current pulse generating circuit boxes and is divided into parts, and the energization paths of these circuit boxes are automatically loaded by loading the upper-level circuit boxes. The vacuum pressure measuring device for a vacuum valve for a vacuum circuit breaker according to claim 1, which is connected. 7. The vacuum circuit breaker for a vacuum circuit breaker according to claim 6, wherein the high-current pulse generating circuit box is provided with a protective lid that operates in synchronization with loading of the energizing path into the connecting part of the energizing path. Vacuum pressure measuring device for vacuum valves.