JPS60194376A - Voltage source circuit - Google Patents

Abstract

PURPOSE:To hold a value in the vicinity of the peak value of transient recovery voltage, by connecting a voltage source capacitor, a reactor, a gap and a commutation capacitor in series and inserting a rectifier between the gap and the commutation condenser. CONSTITUTION:When a close switch 4 is closed, a current is supplied to a breaker 6 from a current source circuit consisting of an electrode 1, a reactor 2 and a shortcircuit transformer 3. A blocking order is issued to an auxiliary breaker 5 and the breaker 6 to block the breaker 6. A gap 11 is ignited before or after a current zero point blocking the current from the current source circuit. Voltage almost corresponding to the charging voltage of a voltage source capacitor 7 appears in a commutation capacitor 12 within a short time. A voltage peak value is held to the commutation capacitor 12 by a rectifier 15.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a voltage source circuit for a synthetic test to verify the breaking performance of a circuit breaker, and particularly to a voltage source circuit suitable for applying and maintaining a high voltage between the electrodes of a circuit breaker. Regarding voltage source circuits.

[Background of the invention]

There are various types of test circuits for examining the breaking performance of a circuit breaker, including a composite test circuit that supplies current and voltage from separate power sources.

FIGS. 1 and 2 are examples of already known synthetic test circuits, which are often used in research and development tests for circuit breakers because they can examine the voltage recovery characteristics between the electrodes after current interruption. In FIG. 1, the current source circuit consists of an electrode 1.0 consisting of a generator or a charged capacitor. Reactor 2. Short circuit transformer 3. Closing switch 4. It consists of an auxiliary circuit breaker 5. Here, 6 indicates a test circuit breaker, and the voltage source circuit includes a voltage source capacitor 7, a high-speed closing switch 8. It consists of a discharge resistor 9.

The voltage source capacitor 7 is charged to a high voltage value V by a separate power supply (not shown). A breaking test for examining the insulation recovery characteristics of the circuit breaker 6 using this circuit will be described below. Auxiliary circuit breaker5.
The circuit breaker 6 is closed, and the closing switch 4. If you turn on the make-up switch 4 while the high-speed make-in switch 8 is open,
Current is supplied to the circuit breaker 6 from the current source. Here, a disconnection command is issued to the auxiliary circuit breaker 5° and the circuit breaker 6, the double-speed circuit breakers begin opening operation, and the current source is disconnected at an arc time corresponding to the circuit breaker 6's circuit breaking performance. Note that the auxiliary circuit breaker 5 is for separating the current source from the voltage source so that the high voltage of the voltage source is not applied to the voltage source circuit.

The voltage source circuit is sequenced so that the fast closing switch 8 is closed before or after the current zero point at which the circuit breaker 6 interrupts the current from the current source. Between the circuit breaker electrodes, there is a time constant τ for charging the floating capacitor 10 (capacitance CS) between the electrodes.
A voltage of Cs' RL is generated. (RL here is the discharge resistance). FIG. 3 shows an example of the voltage waveform. When dielectric breakdown occurs between the electrodes at voltage V, the voltage decreases and discharge resistance RL
A current limited by R1 flows, but since R1 has a high resistance, the current is small and is immediately cut off, and the voltage rises again. Subsequently, dielectric breakdown occurs at V z , V 3, etc., and the envelope shown by the broken line shows the dielectric recovery characteristics with respect to time. Second
The diagram shows basically the same circuit as in FIG. 13 resistors are added. The value of the resistor 13 is extremely small compared to RL, and the value of the commutating capacitor 12 is also smaller than the value of the voltage source capacitor 7 by more than one order of magnitude. Therefore, when the gap 11 is ignited, a voltage equivalent to the charging voltage of the voltage source capacitor appears in the commutation capacitor 12 in a very short time. In this case, the commutation capacitor 12 will function in the same way as the voltage source capacitor 7 in FIG. Here, the charging voltage of the voltage source capacitor has a limit depending on each equipment. On the other hand, in this test method, the voltage applied between the poles of the circuit breaker cannot exceed the charging voltage V due to losses due to discharge, as shown in Figure 3.
It is lower than that. Therefore, if the interrupting performance exceeds the capacity of the equipment, it may not be possible to investigate the limit performance using that equipment. An invention to compensate for these drawbacks has also been made (Japanese Patent Application No. 51-59140), the basic circuit of which is shown in FIG.

The circuit of FIG. 4 has a gap 11 and a commutating capacitor 12. An axle 14 is inserted between the resistors 13. The voltage waveform between the circuit breaker poles in this case is shown in FIG. The voltage waveform changes depending on the size of the limiting resistor RL, but in the case of (a) R, small, as shown by the dotted line, the voltage with a peak value close to twice the charging voltage with an amplitude ratio of about 1.8 to 2 is cut off. Can be applied to the device. However, due to the vibration waveform,
Unable to maintain high voltage. In addition, when dielectric breakdown occurs, the DC current flowing through the circuit breaker increases because RL is small, and the current cannot be interrupted immediately, so the green return waveform of voltage increase as shown in Figure 3 cannot be obtained, and it is not effective. The data will not be obtained. Furthermore, in order to obtain multiple valid data, if RL is increased and the limiting current is decreased, the voltage amplitude rate decreases as shown in Figure 5(b) due to the large RL, resulting in a high voltage. It also means that you won't get it.

[Purpose of the invention]

An object of the present invention is to provide a circuit that can maintain a value near the peak value of an oscillatory transient recovery voltage generated in a voltage source circuit.

[Summary of the invention]

The gist of the invention is that the oscillating current that flows through the voltage source circuit, which consists of an accelerator and a capacitor, reverses its current flow near the voltage peak value, but if the reversal of the current is prevented, the voltage does not drop due to vibration, and the voltage increases. This is because a rectifier was inserted into the circuit.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. 6th
In the figure, a rectifier 15 is added to the voltage source circuit shown in FIG. 4, and the rectifier allows current to flow in the direction of the arrow, but not in the opposite direction. Therefore, the voltage peak value is held in the commutating capacitor 12. FIG. 7 shows the voltage waveform. In the conventional example without the rectifier 15, an oscillating voltage shown by the broken line appears, whereas when the rectifier 15 is inserted, the peak value of the voltage is maintained as shown by the solid line. Here, the interruption test using FIG. 6 is exactly the same in principle as the interruption test using FIG. 2, which has already been explained. In FIG. 2, the voltage charged to the commutating capacitor 12 is at most V, whereas in FIG.
Then, the voltage becomes nearly twice as high as the voltage charged in the voltage source capacitor 7. Therefore, as shown in FIG. 8, the insulation recovery characteristics of the test circuit breaker 6 can be obtained in a voltage range higher than the charging voltage, and data can be obtained from multiple points.

Therefore, according to this embodiment, the voltage source equipment can be doubled and used without adding an expensive capacitor 7 with a large voltage value.

Another embodiment of the invention is shown in FIG. FIG. 9 shows an arrangement in which one more stage voltage amplification circuit is provided in FIG. 6. gap 1
By adjusting so that the discharge of 6 is performed after the discharge of the gap 11, it is possible to generate a voltage in the commutating capacitor 12' that is nearly four times the voltage V charged in the voltage source capacitor 7. In this example, voltage source equipment can be used more effectively. Note that it is also possible to provide this voltage amplification circuit in more stages.

An application example of the present invention in which a rectifier is added to a voltage source circuit is a concave parameter transient recovery voltage generation circuit. Still another embodiment is shown in FIG.

FIG. 10 shows a second voltage source capacitor 18, which replaces the discharge resistor 9 in FIG. Gap 19° Reactor 20. This includes a resistor 21 and a capacitor 22 for voltage waveform adjustment. It is assumed that the voltage source capacitor 7.18 has been charged in advance by a charging device (not shown). FIG. 11 shows the V'+, V2, and V3 waveforms of FIG. 10. If the discharge time of the gap 11 is set to zero and the discharge of the gap 19 is controlled to occur at the time t when the waveform of vI is approximately at its peak value, a voltage shown by v2 is generated and the voltage between the electrodes of the circuit breaker 6 is A voltage v3 appears as the sum of V+ and v2. This voltage waveform can represent a four-parameter waveform. This embodiment has the advantage that a four-parameter voltage waveform can be generated with a relatively simple circuit configuration. In Figure 1, 13' is a resistor, and 14' is an axle.

〔Effect of the invention〕

According to the present invention, a voltage higher than the charging voltage can be maintained and used without adding an expensive voltage source capacitor, so that the voltage source equipment can be used effectively at low cost.

[Brief explanation of the drawing]

Figures 1, 2 and 4 are conventional circuit diagrams, Figures 3 and 5 are conventional circuit diagrams.
The figure is a conventional voltage waveform diagram, Figure 6 is a circuit diagram of an embodiment of the present invention, Figures 7 and 8 are voltage waveform diagrams of Figure 6, Figure 9,
FIG. 10 is a circuit diagram of another embodiment of the present invention, and the Sz diagram is the first embodiment.
FIG. 2 is a voltage waveform diagram of FIG. 15... Rectifier, 11, 16.19... Gap,
7゜18... Voltage source capacitor, 14.14', 2
0...Reactor, 12.12', 22...Commuting capacitor. Agent: Patent Attorney Akio Takahashi (3 meters high, 1 hour, 6 flashes, 6 flashes, q flashes: 80 - 90 points)

Claims (1)

[Claims] ■. Voltage source capacitor, reactor, gap. 1. A voltage source circuit comprising commutating capacitors connected in series, wherein a rectifier is inserted between the gap and the commutating capacitor. 2. The voltage source circuit according to claim 1, characterized in that the voltage source circuit is provided with a voltage amplification circuit. 3. A voltage source circuit according to claim 1 or 2, characterized in that the voltage source circuit is used as a composite test circuit for a circuit breaker. 4. The gap between the voltage source circuit and the circuit breaker according to claim 1 or 2. A second voltage source circuit consisting of the reactor, a resistor for adjusting the transient recovery voltage, and a capacitor is inserted, and the gap of the second voltage source circuit is discharged at approximately the peak value of the transient recovery voltage of the voltage source circuit. A voltage source circuit characterized in that it is configured as follows.