JPH0464151B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] This invention includes a discharge gap with a starting electrode, and a discharge gap arranged on one main electrode side of the discharge gap between the one main electrode and the starting electrode. The present invention relates to a method for extending the continuous usable time of a battery in a discharge gap device in which a battery is used as a power source for a starting circuit for operating a formed starting gap.

[Prior art and its problems]

A discharge gap device is a device that discharges the electric charge of a capacitor that has been charged to a high voltage in advance, and is used to verify the insulation performance of high-voltage equipment and to verify the breaking performance of circuit breakers through synthetic tests. The discharge gap in this device is equipped with a starting electrode, and is formed between the starting electrode and one of the main electrodes to prevent self-destruction or spontaneous discharge at a predetermined discharge voltage, and to control the point of discharge. The starting gap is activated at a predetermined time by a starting circuit provided in the device, and the spark generated at this time is used as a trigger to cause discharge between the main electrodes. FIGS. 1 and 2 show a conventional example of a discharge gap device equipped with this discharge gap with a starting electrode.

FIG. 1 shows a circuit configuration for supplying electric charge from a pre-charged capacitor to a test device via a discharge gap with a starting electrode.
The high potential side terminal is connected to one main electrode 2 of the discharge gap 1 with a starting electrode, and the other main electrode 3 is connected to the test device 8. When operating the discharge gap 1 in a circuit configured in this manner, a signal 11, for example, light, from a signal transmitter 10 installed on the earth potential side is guided to the starting circuit 5 placed on the high potential side, and this signal is Therefore, a starting voltage is generated in the starting circuit 5, and this voltage is applied between the starting electrode 4 and the main electrode 3 to operate the starting gap.

FIG. 2 shows an example of the circuit configuration of this starting circuit 5, in which a switch 12 is closed in advance before the signal 11 is received in this circuit, and a resistor 14 is connected to a battery 13 forming a power source for this circuit. The capacitor 15 is charged via the The insulation resistance 16 between both terminals of the capacitor 15 is not infinite, so a small leakage current is unavoidable.
This minute current continues to flow from the battery 13 while the switch 12 is closed and the test continues. In this state, when the signal 11, for example light, irradiates the solar cell 17, a voltage is generated between both terminals of the solar cell 17, so the thyristor 18 becomes conductive.
The charge in the capacitor 15 is discharged via the low voltage winding 19a of the step-up transformer 19 and the thyristor 18,
A high voltage is generated across all windings 19b. This high voltage is applied between the starting electrode 4 and the main electrode 3, and a spark 20 is applied to the starting gap formed between the two electrodes.
This spark acts as a trigger to generate a main arc 21 between the main electrodes 2 and 3, and one test is completed.

The test interval between each test conducted in this way may be on the order of minutes or hours, but even when it is on the order of hours, the continuous use time of the battery is prevented from being shortened due to the outflow of the leakage current. Opening the switch 12 for each test is not possible because the discharge gap device 6 (Fig. 1) is usually installed at a high place and because structures cannot be installed nearby for insulation reasons. Since it was necessary to move the transport scaffold to perform the work, and it was necessary to close the switch again during the test, it was decided that the tester would be responsible for completing both the test and the work, and the circuit was opened. Test efficiency problems such as redoing the test due to forgetting to close the switch, etc.
There were issues such as the merits of extending the continuous use time of the battery compared to the amount of work. Particularly when testing is performed in combination with a large-capacity short-circuit generator, the loss in power costs associated with redoing the test cannot be ignored.

[Purpose of the invention]

The purpose of the present invention is to automatically extend the continuous usable time of a battery without relying on any manual work as described above.

[Key points of the invention]

The present invention includes a discharge gap with a starting electrode, and a power source for a starting circuit that operates the starting gap arranged on one main electrode side of the discharge gap and formed between the one main electrode and the starting electrode. In a discharge gap device that is a battery, an impedance is connected in series with the one main electrode, and the battery is charged via a rectifier by the voltage across the terminals of the impedance generated by the discharge current when the discharge gap is activated. The aim is to automatically extend the continuous usable time of a battery without any manual work.

[Embodiments of the invention]

FIG. 3 shows a first embodiment of the present invention. In this embodiment, a resistor 22 is connected in series with the main electrode 3, and when the discharge gap 1 is activated, a discharge current flowing through the main electrodes 2 and 3 creates a potential difference between both terminals of the resistor 22. The battery 13 is charged via a charging resistor 23 and a rectifier 24. An example of calculation for determining circuit constants for making the charging energy obtained between both terminals of the resistor 22 equal to the starting energy consumed in one test will be shown below.

The type of test to be calculated now is a composite short circuit test of a circuit breaker, and the peak value of the breaking current that the circuit breaker should interrupt and its frequency are respectively √2×50kA,
Assuming 50Hz (half cycle is 10ms), main electrodes 2 and 3
The discharge current flowing through usually has a peak value of √2
A waveform of ×5kA and half-cycle of 1ms sine wave is selected. Now the resistance value of resistor 22 is R ₂₂ [Ω], resistance 2
The resistance value of battery 13 is R ₂₃ [Ω], and the internal resistance of battery 13 is
R ₁₃ [Ω], the current waveform approximately has a peak value of 5kA,
Assuming a rectangular wave with a time width of 1 ms, the amount of charge flowing into the battery 13 during this 1 ms is Q ₁ = (5000 x R ₂₂ - V ₁₃ )/R ₂₂ + R ₂₃ + R ₁₃ x 1 x 10 ^-3
[Coulomb] (1) Here, V ₁₃ is the terminal voltage of the battery 13. Note that since the resistance value of the resistor 14 is on the order of MΩ, there is no need to consider it here. Also, since 5000×R ₂₂ is the voltage for charging the battery, it is selected to be _{a voltage higher than the terminal voltage of the battery, V 13 .}
If +ΔV, then Q ₁ =ΔV/R ₂₂ +R ₂₃ +R ₁₃ ×10 ^-3 [Coulomb] (2).

On the other hand, the terminal voltage V ₁₃ of battery 13 is 100 volts,
Assuming that the capacitance C ₁₅ of the capacitor 15 is 20 μF, the amount of charge consumed in one test is: Q ₂ = C ₁₅ V ₁₃ = 20 × 10 ^-6 × 100 = 2 × 10 ^-3 [coulombs] (3) Therefore, if the amount of charge consumed in each test is replenished from both terminals of the resistor 22, then from Q ₁ =Q ₂ (4), ΔV=2(R ₂₂ +R ₂₃ +R ₁₃ ) (5). Here, R ₂₂ is automatically determined from the above relationship if ΔV is given, so R ₂₃ + R ₁₃ can be expressed as (5)
By determining the value in accordance with the formula, the amount of charge consumed for each test is replenished. For example, if ΔV = 20 volts, R ₂₂ = (100 + 20) /
5000 = 0.024 [Ω], so it can be seen from equation (5) that it can be determined according to R ₂₂ + R ₁₃ = 9.976 [Ω].

However, as mentioned above, during the test, the battery 13
Since leakage current is constantly flowing out from the battery, if this loss is also replenished, the battery can be used continuously for an extremely long time. This loss is, for example, the resistance value R 14 of resistor ₁₄ = 1 [MΩ], and the resistance value of resistor 16
Assuming that the resistance value R ₁₆ = 10 [MΩ] in (Fig. 2) and the test time interval T = 1 [h] = 3600 [s], ΔQ = V ₁₃ /R ₁₄ +R ₁₆ ×T = 100 / 11× ¹⁰⁶ ×3600=0.03
3 [coulombs], this loss can be compensated for by finding _{R 23 +} R ₁₃ using Q ₂ +ΔQ instead of Q 2 in equation (4).

In the above calculation example, the discharge current peak value is √2×5kA,
We have shown the case of a half-sine wave waveform with a half-cycle time of 1 ms, but since there are various waveforms of discharge current during testing depending on the type of test, it is possible to achieve the purpose with any current waveform. Therefore, it is preferable that both resistors 22 and 23 be made variable so that they can be set to a required resistance value prior to the start of the test.

In the above embodiments, the impedance connected in series with one of the main electrodes is a resistance, but instead of the resistance, a current transformer 24 may be used as in the second embodiment shown in FIG. can be reached. In this current transformer, the flow time of the discharge current is usually short, on the order of milliseconds or less, so there is no need to consider temperature rise due to energization, and therefore an extremely small size can be used, and the main electrode can be easily accommodated in the inner space of the However, since it is desirable that the voltage obtained on the secondary side of this current transformer be almost constant, exceeding the terminal voltage of the battery, regardless of the primary discharge current, the number of taps in the secondary winding is increased. At the same time, it is preferable to finely adjust the battery recharging current by changing the set value of the resistor 23.

〔Effect of the invention〕

As described above, according to the present invention, an impedance is connected in series with one of the main electrodes in the discharge gap device, and the voltage between the terminals of the impedance generated by the discharge current when the discharge gap is activated is used to reduce the voltage between the terminals of the impedance through the rectifier. The simple additional cost of recharging the battery with the switch 12 may cause test efficiency problems such as redoing the test due to forgetting to close an open switch, such as when the switch 12 is opened or closed artificially. The effect is that the continuous usable time of the battery can be automatically extended without causing problems such as the merits of extending the continuous usable time of the battery when compared with the amount of work required to open and close the battery.

[Brief explanation of drawings]

Figure 1 is a diagram showing an example of a circuit configuration when discharging the charge of a capacitor via a discharge gap with a starting electrode, and Figure 2 is a diagram showing an example of a circuit configuration when discharging the charge of a capacitor through a discharge gap with a starting electrode. FIG. 3 is a diagram showing an example of the conventional circuit configuration of the circuit, FIG. 3 is a diagram showing the first embodiment based on the present invention, and FIG. 4 is a diagram showing the second embodiment.
It is a figure showing an example of. 1... Discharge gap with starting electrode, 2, 3...
Main electrode, 4... Starting electrode, 5... Starting circuit, 6...
...Discharge gap device, 13...Battery, 22, 23
...Resistance, 24...Current transformer.

Claims (1)

[Scope of Claims] 1. A starting circuit that includes a discharge gap with a starting electrode and that operates the starting gap that is arranged on one main electrode side of the discharge gap and formed between the one main electrode and the starting electrode. In a discharge gap device whose power source is a battery, an impedance is connected in series with the one main electrode, and the battery is charged via a rectifier by the voltage across the terminals of the impedance generated by the discharge current when the discharge gap is activated. A discharge gap device characterized by: 2. The discharge gap device according to claim 1, wherein the impedance connected in series with one main electrode of the discharge gap is a resistance. 3. The discharge gap device according to claim 1, wherein the impedance connected in series with one main electrode of the discharge gap is a current transformer.