JPH04313086A - Synthesized short-circuit testing circuit - Google Patents

Abstract

PURPOSE:To make charging polarity variable in addition to use as a single power supply by applying the second output voltage on the capacitor of a voltage source circuit through the charging breaker of the voltage source circuit, and cutting off an advanced current flowing through the voltage source capacitor. CONSTITUTION:Before the short-circuit test, an inputs switch 2 and an auxiliary breaker 5 are opened, and a breaker under test 6 and a breaker 12 for charging a voltage source circuit are closed. When the switch 2 is closed at an arbitrary time, a voltage is applied from a short-circuit generator 1 on the primary winding of a step-up transformer 4 through the switch 2 and a reactor 3 for adjusting the shortcircuit current. At the secondary side of the transformer 4, a closed circuit including the breaker 12 and a capacitor 11 of the voltage source circuit is formed through a high-voltage tap. At this time, the phase-advanced current, which is approximately determined by the generated voltage in the secondary side of the transformer 4 and the capacitor 11, flows through the breaker 12.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic short circuit test circuit used to verify the breaking performance of a power circuit breaker.

0002

2. Description of the Related Art FIG. 4 is a diagram showing a synthetic short-circuit test circuit based on the Wilde-Puket method disclosed in JEC-2000, for example. In the figure, the primary winding of the step-up transformer (4) includes a closing switch (2) and a short-circuit current adjustment reactor (3).
) is connected to the short-circuit generator (1). An auxiliary breaker (5) and a test breaker (6) whose breaking performance is to be verified are connected in series to the secondary winding of the step-up transformer (4). A current source circuit is configured by each of the above sections (1 to 6). A series body of a transient recovery voltage adjustment resistor (7) and a capacitor (8) is connected in parallel with the circuit breaker under test (6), and the circuit breaker under test (6) is further connected to a voltage source circuit reactor (9). , a starting discharge gap (10), and a voltage source circuit capacitor (11) are connected in parallel. The voltage source circuit capacitor (11) is connected to the rectifier (1
4) is connected to the power supply (13). A voltage source circuit is configured by each of the above parts (7 to 11, 13, 14).

Next, the operation of the above conventional example will be explained. First, the auxiliary circuit breaker (5) and the test circuit breaker (6) are closed, and the voltage source circuit capacitor (11) is supplied with a predetermined voltage from the high voltage power supply (13) via the rectifier (14). Charge the battery in advance. Next, when the closing switch (2) is turned on at an arbitrary time, the auxiliary circuit breaker is connected from the short-circuit generator (1) to the closing switch (2), the current adjustment reactor (3), and the step-up transformer (4). A predetermined short circuit current is applied in series between (5) and the test circuit breaker (6). Both circuit breakers (5, 6) are opened at a predetermined time to be verified, a breaking arc is generated, and the starting gap (10) is operated at a predetermined time immediately before the current zero point. The operation of the starting gap (10) causes the electric charge stored in the voltage source circuit capacitor (11) to be discharged.

When the short circuit current is interrupted by the auxiliary circuit breaker (5) and the circuit breaker under test (6), the circuit breaker under test (6) includes a voltage source circuit reactor (9), a transient recovery voltage adjustment A transient recovery voltage is applied with a frequency and amplitude rate approximately determined by the resistor (7) and capacitor (8).

[0005]

In the conventional synthetic short-circuit test circuit as described above, it is necessary to charge the voltage source circuit capacitor (11) with a predetermined voltage prior to testing. Therefore, separate from the short-circuit generator (1), the high voltage power supply (1
3) and a rectifier (14) must be prepared, which is inconvenient. Furthermore, if it is desired to change the voltage polarity of the transient recovery voltage, the mounting direction of the rectifier (14) must be changed, which is inconvenient. This invention was made to solve the above problems, and provides a synthetic short circuit test circuit that can be driven by a single power source and can easily change the charging polarity of the voltage source circuit capacitor (11). The purpose is to provide

[0006]

[Means for Solving the Problems] The present invention provides a composite short-circuit test circuit for a circuit breaker under test, which includes a current source circuit and a voltage source circuit, wherein the current source circuit has a first output voltage and a voltage source circuit. The voltage source circuit includes a step-up transformer having a second output voltage that is higher than the first output voltage, and the voltage source circuit has a closed circuit that uses the second voltage as a circuit power source. The voltage source circuit includes a voltage source circuit capacitor to be configured, and a voltage source circuit charging circuit breaker inserted into the closed circuit to interrupt the lead current flowing to the voltage source circuit capacitor.

[0007]

[Operation] In this invention, the voltage source circuit charging circuit breaker interrupts the leading current flowing through the closed circuit at its zero point due to the second output voltage of the step-up transformer, and transfers the voltage at that point to the voltage source circuit capacitor. to remain.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a circuit diagram showing an embodiment of the present invention. In the figure, the primary winding of the step-up transformer (4) includes a closing switch (2) and a short-circuit current adjustment reactor (3).
) is connected to the short-circuit generator (1). An auxiliary circuit breaker (5) and a test circuit breaker (6) whose interrupting performance is to be verified are connected in series between one end of the secondary winding of the step-up transformer (4) and the intermediate tap. ing. A series body of a transient recovery voltage adjustment resistor (7) and a capacitor (8) is connected in parallel with the circuit breaker under test (6), and the circuit breaker under test (6) is further connected to a voltage source circuit reactor (9). , a starting discharge gap (10), and a voltage source circuit capacitor (11) are connected in parallel. The voltage source circuit is connected between point A, which is the connection point between the starting discharge gap (10) and the voltage source circuit capacitor (11), and the other end (high voltage tap) of the step-up transformer (4). circuit breaker (12) is connected. As the voltage source circuit charging circuit breaker (12), for example, one having voltage resistance performance equal to or higher than that of the test circuit breaker (6) is used.

Next, the operation of the above embodiment will be explained. First, prior to the short circuit test, the closing switch (2) and the auxiliary circuit breaker (5) are opened. In addition, the test circuit breaker (
6) and voltage source circuit charging circuit breaker (12). After the above preparations are completed, when the closing switch (2) is turned on at any time, the short-circuit generator (1) will be transferred from the closing switch (
A voltage is applied to the primary winding of the step-up transformer (4) via the short-circuit current adjusting reactor (3) and the short-circuit current adjusting reactor (3). On the secondary side of the step-up transformer (4), a closed circuit including a voltage source circuit charging circuit breaker (12) and a voltage source circuit capacitor (11) is formed via a high voltage tap. At this time, the voltage source circuit charging circuit breaker (12) is connected to the step-up transformer (4).
A leading phase current approximately determined by the secondary side generated voltage and the voltage source circuit capacitor (11) flows.

FIGS. 2 and 3 show a voltage source circuit charging circuit breaker (
12) is a graph showing the current waveform (dotted chain line) and the voltage waveform at point A (solid line) when the current is interrupted. As shown in FIG. 2, when the voltage source circuit charging circuit breaker (12) opens when the current has a negative value (time T1), the interruption is performed at the next current zero point (time T2). In the voltage source circuit capacitor (11), a charge having a polarity and magnitude determined by the voltage phase and instantaneous voltage value at the time of interruption remains as a DC voltage, and charging is completed at that point. . That is, the residual voltage -Vr shown in FIG. 2 is finally charged in the voltage source circuit capacitor (11). Similarly, as shown in FIG. 3, when opening is performed when the current is a positive value, a residual voltage +Vr is finally charged in the voltage source circuit capacitor (11). In addition, since there is a time delay between when the voltage source circuit charging circuit breaker (12) is given the cutoff command signal and when it actually opens, the cutoff command signal is calculated at the time when the time delay is calculated backward from time T1. must be submitted to In this way, the voltage source circuit capacitor (11)
Voltage source circuit charging circuit breaker (
12) After opening the circuit, the closing switch (2) is also opened.

Next, after turning on the auxiliary circuit breaker (5), when the closing switch (2) is turned on at any time, the short-circuit generator (1) is disconnected from the closing switch (2), the current adjustment reactor (3), and the booster voltage. Auxiliary circuit breaker (
5) and the test circuit breaker (6) in series with a predetermined short circuit current. Both circuit breakers (5, 6) are opened at a predetermined time to be verified, a breaking arc is generated, and the starting gap (1) is opened at a predetermined time immediately before the current zero point.
0). The operation of the starting gap (10) causes the electric charge stored in the voltage source circuit capacitor (11) to be discharged. Auxiliary circuit breaker (5) and test circuit breaker (6)
When the short circuit current is interrupted by
A transient recovery voltage having a frequency and an amplitude rate approximately determined by the voltage source circuit reactor (9), the transient recovery voltage adjustment resistor (7), and the capacitor (8) is applied to.

[0012] In the above embodiment, a synthetic short-circuit test circuit using the Wildepke current superimposition method has been described, but the present invention can be similarly implemented in a synthetic short-circuit test circuit using the voltage superimposition method.

[0013]

As described above, according to the present invention, the second output voltage of the step-up transformer is applied to the voltage source circuit capacitor via the voltage source circuit charging circuit breaker, and the current flowing through the voltage source capacitor is By cutting off the current, the current voltage remains in the capacitor, which has the effect of providing not only a current source but also a charged capacitor as a voltage source from a single power source. . Furthermore, there is also the effect that the charging polarity of the capacitor can be easily changed by changing the timing of breaking the voltage source circuit charging circuit breaker.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

2 is a graph showing a current waveform flowing through the voltage source circuit charging circuit breaker (12) shown in FIG. 1 and a voltage waveform Vr at point A in FIG. 1;

FIG. 3 is a graph similar to FIG. 2, but when the timing of current interruption is of opposite polarity to that shown in FIG. 2;

FIG. 4: Conventional synthetic short circuit test circuit.

[Explanation of symbols]

1. Short circuit generator 2.　　　　　　　　　　　On switch 3. Current adjustment reactor 4.　　　　Step-up transformer 5. Auxiliary circuit breaker 6. Test circuit breaker 7.　　　　　　　　Transient recovery voltage adjustment resistor 8. Capacitor 9. Voltage circuit reactor 10.　　　　Starting discharge gap 11. Voltage source circuit capacitor

Claims (1)

[Claims] Claim 1. A composite short circuit test circuit for a circuit breaker under test, which includes a current source circuit and a voltage source circuit, wherein the current source circuit has a first output voltage and a second output voltage higher than the first output voltage. The voltage source circuit includes a step-up transformer having an output voltage, the first output voltage of which is used as a circuit power source, and the voltage source circuit includes a voltage source circuit capacitor that is to form a closed circuit that uses the second voltage as a circuit power source. , a voltage source circuit charging circuit breaker inserted into the closed circuit to interrupt the lead current flowing to the voltage source circuit capacitor.