JPS5845669B2 - Equivalent testing device for breaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an equivalent testing device for circuit breakers, and particularly to an equivalent testing device suitable for generating a four-parameter re-electromotive voltage.

FIG. 1 shows the well-known Weyl equivalent test circuit.

A circuit is configured to supply current to the transformer 5 through a protective breaker 2, a closing switch 3, and a current adjustment reactor 4 connected in series with the generator 1.

A series circuit consisting of an auxiliary breaker 6 and a test breaker 7 is formed on the secondary side of the transformer 5, so that a large current from the generator 1 can flow therethrough.

This part is called a current source circuit.

On the other hand, a capacitor 8, a control gap 9, a reactor 10,
The series circuit of the resistor 11 and the capacitor 12 is called a voltage source circuit, and as shown in the figure, the connection between the reactor 10 and the resistance 11 is connected to the connection between the auxiliary breaker 6 and the test breaker 7.

Both the auxiliary breaker 6 and the test breaker 7 are closed, the generator voltage is adjusted with the protective breaker 2 closed, the closing switch 3 is closed, and a specified short-circuit current is applied to the current source circuit. Flow.

The voltage of the current source circuit may be relatively low.

At an appropriate time, a breaker command is given to the auxiliary breaker 6 and the test breaker 7 to open them at the same time, and at the final point of the current source current IC, the second As shown in the figure, a voltage source current iv is applied.

When the breaking performance is sufficiently good, as shown in FIG. 2, the voltage source current iv flows only half a wave and is cut off, so that a prescribed high voltage 7 is applied to the test breaker 7.

Generally, the voltage source current iv is 1/ compared to the current source voltage ic.
The frequency is about 10 times that of the current source circuit, and the current change rate at the current zero point is selected to be approximately equal to that of the current source.

Through recent research and development, the voltage per point of circuit breakers has continued to rise, and single-point circuit breakers with a rated voltage of about 168 KV are now being manufactured.

According to the breaker standard, for example, JRC-181, for a breaker with a rated voltage of 120 or more, a re-electromotive voltage is specified using a four-parameter method in the case of a rated breaking current.

For example, if there is one voltage maximum value before the voltage peak value as shown in Figure 3, the first tangent line drawn from the origin to the voltage peak value will touch the voltage peak value and the voltage peak value. Second
It is recommended that a third tangent drawn parallel to the time axis t through the voltage peak value and a third tangent be drawn in parallel to the time axis t, and then apply a re-electromotive voltage waveform that has these three tangents as an envelope.

However, in the Weyl circuit of FIG. 1, only a simple waveform such as the re-electromotive voltage waveform a or b shown in FIG. 3 can be applied.

When testing with a restart voltage waveform a that satisfies the maximum voltage value,
Dielectric breakdown may occur near voltage 2 at time t1.

Because a severe voltage higher than the specified value was applied during a short period of time for the current to break or break, it cannot necessarily be determined that the product has passed the test.

On the other hand, even if a waveform passing through point P does not cause dielectric breakdown, it cannot be said to pass because it does not satisfy the peak value ■2.

Because of these circumstances, test circuits that generate four-parameter restart voltages at various locations have been devised.

FIG. 4 shows an example of a known four-parameter re-electromotive voltage generating circuit.

A second auxiliary breaker SH is installed between the current source circuit and the voltage source circuit.
, and make it cut off near t0 in Figure 3.
The current source voltage is boosted by a transformer Tr and added to the voltage source voltage to obtain a four-parameter restart voltage.

CT is a current detecting current transformer, and GST is a device for controlling discharge of the control gap 9.

Reactor L9, resistor R, and capacitor C5 are for adjusting applied voltage.

The conventionally known embodiment of FIG. 4 requires an auxiliary breaker SH which can operate at extremely high speed and has excellent breaking performance.

Such an auxiliary circuit breaker SH is difficult to obtain in general laboratories, and there are also problems in terms of price and the like.

For this reason, there has been a desire for an equivalent test circuit that can generate a four-parameter re-electromotive voltage more cheaply and easily.

An object of the present invention is to provide an equivalent test device that generates a four-parameter re-electromotive voltage using a simple structure and an easily available auxiliary switch and disconnector.

The present invention opens the conventional auxiliary breaker before opening so that an ordinary high-voltage breaker can be used without using a breaker that requires extremely high-speed operation corresponding to SH in Fig. 4. The arc is sustained and extinguished at a predetermined point.

For example, instead of creating a current zero point by supplying direct current or low-frequency alternating current in accordance with the opening of an auxiliary breaker, a current zero point is forcibly created at a predetermined point of time.

The present invention will be explained below with reference to embodiments shown in the drawings.

FIG. 5 is a detailed explanatory diagram of the present invention, and FIG. 6 is an explanatory diagram of its phenomenon.

Part names with the same numbers as in FIG. 1 are assumed to have the same functions as in FIG. 1, and detailed explanations will be omitted.

A second auxiliary breaker 22 is connected in series between the connection point of the first auxiliary breaker 6 and the test breaker 7 and the reactor 10, and is connected in series in parallel with this second auxiliary breaker 22. A cutoff timing adjustment circuit consisting of a charging capacitor 14, a control gap 17, and a current-limiting handle 20, and a second current source consisting of a charging capacitor 13, a control gap 16, and a current-limiting resistor 19 connected in series. It has a circuit.

This second current source circuit supplies direct current or low frequency current, and the second current source circuit supplies direct current or low frequency current until a predetermined point in time.
This is a cut-off point adjustment circuit designed not to supply a current zero point to the auxiliary circuit breaker 22, and is connected in parallel with the cut-off time adjustment circuit.

The waveform adjustment capacitor 15 is connected in parallel with the second auxiliary breaker 22.

18 is a current limiting resistor, and capacitors 13 and 14 of the cutoff point adjustment circuit and the second current source circuit are connected in parallel to the gap 17.

21 is a disconnector.

With the first auxiliary breaker 6 and the test breaker 7 closed, the disconnector 21 is closed, and the capacitors 13 and 14 are charged at the same time as the capacitor 8 from a charging device (not shown).

Prior to starting the test, the disconnector 21 is opened.

In this test circuit as well, the charge of the capacitor 8 is transferred to the gap 9 and the reactor 10 just before the final zero point of the current source current IC.
, the application through the second auxiliary breaker 22 is applied to the first
It is no different from the case shown in the figure.

In this test, the second auxiliary breaker 22 does not require particularly high-speed operation, unlike the conventionally known high-speed breaker SH shown in FIG.

Shortly before the second auxiliary breaker 22 is opened, the control gap 16 of the breaker time delay circuit is discharged, and an appropriate magnitude of, for example, DC current ipc is caused to flow through the resistor 19 to the second auxiliary breaker 22.

In this state, the distance between the poles of the second auxiliary breaker 22 is increased with a DC arc being applied until the pole gap of the second auxiliary breaker 22 can sufficiently withstand the re-electromotive voltage between the poles.

At this point, the voltage source current iv shown in FIG. 6 is applied as described above, and when the test breaker 7 successfully interrupts iv and iv is interrupted by a half-wave, the current passing through the second auxiliary breaker 22 starts flowing again. It becomes direct current.

In this case, since the current passing through the second auxiliary breaker 22 has no current zero point, the current is not interrupted, and the second auxiliary breaker 22 is in a conductive state due to the arc current.

Therefore, the test breaker 7 is a voltage source current breaker, and a voltage range from t3 to t4 as shown in FIG. 6U, for example, is placed between its poles.

Near the maximum value of the voltage between electrodes, the control gap 17 of the cutoff timing adjustment circuit is discharged, and the electric charge charged in the capacitor 14 is oscillatedly discharged as a current iv' through the inductance 20 and the second auxiliary breaker 22. do.

At that point, if the peak value of the added oscillating current itself is made slightly larger than the DC current flowing through the second auxiliary breaker 22, the total current passing through the second auxiliary breaker 22 will have a current zero point. and is cut off at point 15 in FIG.

After that, a current flows through the circuit of the capacitor 14, control gap 17, reactor 20, and capacitor 15, and the voltage between the poles of the second auxiliary breaker 22, which is equal to the terminal voltage of the capacitor 15, is superimposed on the re-EMF voltage of the conventional Weyl circuit. be done.

The polarity of the capacitors 8 and 14 is reversed after a half-wave of oscillating current is passed through the capacitor, whereas the polarity of the voltage of the capacitor 13 is not reversed because it is discharged through a sufficiently large resistance.

This situation is shown by the 10- symbols drawn on both ends of the capacitor.

Depending on the capacitance of the capacitors 13, 14 and 15, the second auxiliary breaker 22 may be connected, for example as shown in FIG.
The voltage appearing in
By appropriately selecting the value of , it is possible to select the circuit constants such that its polarity is soon reversed and a maximum value occurs in the voltage across the poles of the breaker under test.

According to this embodiment, the fourth conventional example of the four-parameter generating circuit
A transformer T that can generate high voltage at both terminals was required in the diagram.
4. An expensive high-speed circuit breaker SH, etc., which operates with high reliability in an extremely short period of time, is not required, and a four-parameter generation circuit can be constructed economically.

By adjusting the discharge start time of the control gap 17 corresponding to t4, the waveform of the re-electromotive voltage generated across the test breaker 7 can be adjusted relatively easily.

In particular, in the example shown in Fig. 4, a high-voltage transformer T with both terminals on the high-voltage side of the winding floating above the ground voltage was required, whereas in this embodiment, such a transformer is not required. .

In FIG. 5, both capacitors 13 and 14 are configured to be charged to the same voltage as capacitor 8, but at least one of capacitors 13 and 14 is charged to a lower voltage than capacitor 8 using a resistor voltage division method or the like. Charging is also effective in adjusting the restart voltage waveform.

In addition, by inserting a suitable resistor in series with the capacitor 15, the amplitude ratio of the voltage appearing across the capacitor 15 is adjusted.
By these methods, it is possible to adjust the peak value of the four-parameter re-electromotive voltage between the poles of the test breaker.

Furthermore, it is also possible to connect a resistor of an appropriate value in parallel with the capacitor 15 and adjust the recovery voltage of the test breaker to an appropriate value depending on the ratio with the resistor 19.

Furthermore, if the capacitor 14 is charged in advance in the opposite direction to the case shown in FIG. 5 by using a different charging circuit, it is possible to charge the capacitor 14 in a relatively short time after the discharge of the three-point gap 17 with the trigger electrode starts. Since a current zero point can be created in the current passing through the second auxiliary breaker 22, the waveform can be easily adjusted when applied to a test breaker in which the time required to reach the peak value of the re-electromotive voltage is short. .

FIG. 7 shows another embodiment.

In this example, a high voltage transformer T is used as in the example shown in FIG.

In parallel with the second auxiliary circuit breaker 22, there is a cut-off time delay circuit, which is a second current source, consisting of a resistor 19, a capacitor 13', and a gap 16; A cutoff point adjustment circuit that works together with the circuit to supply a current zero point to the auxiliary breaker 22, and a transformer Tr, a resistor R8, and an inductance L that apply a predetermined high voltage to the auxiliary breaker 22.
8. The second high voltage circuit consists of 8 circuits.

The operation is almost the same as in the previous embodiment, and the second auxiliary breaker 2
2 is discharged in the gap 16 prior to the opening of the auxiliary breaker 22 to delay the cutoff point of the auxiliary breaker 22, and with the auxiliary breaker 22 fully open, the discharge is made in the gap 17 to generate an oscillatory current by the cutoff point adjustment circuit. is supplied to the auxiliary breaker 22.

When the auxiliary breaker 22 enters the cut-off state using the same principle as in the previous embodiment, the re-electromotive voltage on the secondary side of the transformer Tr appears in the test breaker T and is superimposed on the voltage of the first voltage source. Ru.

According to this embodiment, the same effects as in the previous embodiment can be obtained except that a high voltage transformer Tr is used.

In this embodiment, since the capacitor 13' is selected so that discharge continues in the gap 16 immediately after the auxiliary breaker 22 is turned off, the voltage applied to the auxiliary breaker 22 is adjusted by this capacitor 13'. However, as shown in the example in Figure 4, the applied voltage adjustment capacitor C
8 may be placed separately.

As described above, according to the present invention, the cutoff time adjustment circuit and the cutoff time adjustment circuit are provided to control the cutoff time of the second auxiliary breaker. Alternatively, readily available auxiliary circuit breakers can be used.

[Brief explanation of drawings]

Figure 1 is a known Weyl test circuit diagram, Figures 2 and 3.
1 is a diagram explaining the test of FIG. 1, FIG. 4 is a conventional four-parameter re-electromotive voltage generation circuit diagram, FIG. 5 is a circuit diagram of an equivalent test device according to an embodiment of the present invention, and FIG. Figure test illustration,
FIG. 7 is a circuit diagram of an equivalent test device showing another embodiment of the present invention. 6... First auxiliary breaker, 7... Test breaker,
13.14... Charging capacitor, 16.17...
Control gap, 19... Current limiting resistor, 20...
Reactor, 22...second auxiliary breaker.

Claims (1)

[Claims] 1 A series circuit of a first auxiliary breaker and a test breaker,
A current source that supplies a short-circuit large current to this series circuit, and a voltage source circuit that supplies a voltage source current to the test breaker via a second auxiliary breaker, wherein the second
A cut-off point adjustment circuit having a control gap is provided in parallel with the auxiliary breaker, and a cut-off point adjustment circuit having a different control gap is provided in parallel with the control gap and the second auxiliary breaker; A breaker equivalency test device characterized in that the zero point of the current flowing through the second auxiliary breaker is given by: