JP3139178B2 - Hybrid switchgear - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid switch combining a thyristor switch with a mechanical switch having mechanical contacts.

[0002]

2. Description of the Related Art FIG. 6 shows a conventional hybrid switch. In FIG. 6, a mechanical switch M is disposed at a position separated from a main fixed contact 1 by a predetermined distance from the main fixed contact. Auxiliary fixed contact 2
And the movable contact 3.

The main fixed contact 1 is a sliding contact having a structure in which a large number of contact pieces 1a arranged in a ring are urged radially inward by a spring 1b (a type of a sliding contact relatively to a movable contact). The auxiliary fixed contact 2 forms a large number of contact pieces arranged in an annular shape by making a large number of splits in the axial direction on the peripheral wall portion of the tubular conductive member 2a. Is urged inward in the radial direction by a spring 2b. The contact piece constituting the main fixed contact is made of hard copper, and its surface is silver-plated.

The movable contact 3 comprises a main fixed contact 1
, A tubular movable conductor 3a supported in a state of slidably penetrating a current collecting contact 4 disposed opposite to the auxiliary fixed contact 2, and a main body connected to the distal end of the movable conductor 3a. It comprises a main movable contact 3b which comes into contact with the fixed contact from the inside, and an auxiliary movable contact 3c provided so as to protrude from the tip of the main movable contact.

The auxiliary movable contact 3c has a smaller diameter than the main movable contact 3b so as not to contact the main fixed contact 1, and is configured to make sliding contact (sliding contact) with the auxiliary fixed contact 2 from the inside. Have been. The movable contact 3 is connected to an operating device via an insulating operating rod (not shown), and the main movable contact 3b and the auxiliary movable contact 3c come into contact with the main fixed contact 1 and the auxiliary fixed contact 2, respectively, as shown. The main movable contact 3b and the auxiliary movable contact 3c are displaced between the main fixed contact 1 and the auxiliary fixed contact 2 at a predetermined insulating distance from the closed position.

In this switch, at the time of closing, first, the auxiliary movable contact 3c contacts the auxiliary fixed contact 2, then the main movable contact 3b contacts the main fixed contact 1, and when the circuit is opened, the main movable contact 3b is connected to the main fixed contact 1. The main fixed contact 1 so that the auxiliary movable contact 3 c separates from the auxiliary fixed contact 2 after being separated from the main fixed contact 1.
In addition, the positional relationship between the auxiliary fixed contact 2 and the dimensions of each part of the movable contact 3 are set.

The thyristor switch T comprises thyristors 5 a and 5 b connected in anti-parallel, and is connected between the main fixed contact 1 and the auxiliary fixed contact 2. In the hybrid switch, an external circuit including a load 6 and an AC power supply 7 is connected between the main fixed contact 1 and the movable contact 3. In the illustrated example, the main fixed contact 1 is connected to one end of the power supply 7, and the current collecting contact 4 is connected to the other end of the power supply 7 via the load 6.

The thyristor switch T is turned on when the movable contact 3 is separated from the main fixed contact 1 at the time of opening, and is cut off before the movable contact 3 is separated from the auxiliary fixed contact 2. The contact circuit 2 is controlled by a control circuit (not shown) so that the contact is made conductive and the movable contact 3 is cut off after coming into contact with the main fixed contact 1.

When opening the above hybrid switch,
The moment the main movable contact 3b separates from the main fixed contact 1, the load current is diverted to the thyristor switch T, and the load current is transferred to the thyristor switch T and the auxiliary fixed contact 2.
After the thyristor switch T is turned off at the current zero point, the auxiliary movable contact 3 c is detached from the auxiliary fixed contact 2. Thus, the current can be cut off with almost no arc.

When the switch is turned on, the auxiliary movable contact 3c is brought into contact with the auxiliary fixed contact 2 and then the thyristor switch T is turned on while controlling the phase to start energizing the load with almost no arc. I do. Thereafter, the main movable contact 3b is brought into contact with the main fixed contact 1, and the thyristor switch T is turned off.

As described above, since the load can be turned on and off almost without arc, the load can be frequently switched.

[0012]

In the above-mentioned hybrid switch, the thyristor switch T is responsible for opening and closing the current, so that if the thyristor switch fails, the current cannot be cut off. In particular, when the mechanical switch M is housed in a container in which an insulating gas or the like is sealed, if the current cannot be cut off, the internal pressure of the container may rise and cause an explosion, which is dangerous.

Therefore, in the hybrid switch, it is preferable to appropriately check whether the thyristor switch T operates normally. However, in the conventional main switch, the thyristor switch T is closed in a closed state. Since T was connected to the main circuit through the auxiliary fixed contact and the auxiliary movable contact, it was not possible to check whether the thyristor switch was sound during energization. Therefore, it is not possible to confirm whether or not the thyristor switch operates normally until the switch is actually opened, and there is a problem that reliability is poor.

It is an object of the present invention to provide a hybrid switch capable of checking a thyristor switch even while power is being supplied.

[0015]

The hybrid switch according to the present invention has a main fixed contact 11 and an auxiliary fixed contact 12 as shown in FIG.
And a main movable contact 1 movably provided between a closed position in contact with the main fixed contact 11 and an open position at a predetermined insulating distance from the main fixed contact.
3b and the main movable contact, so that the main movable contact comes into contact with the auxiliary fixed contact 12 immediately before leaving the main fixed contact, and separates from the auxiliary fixed contact before the main movable contact reaches the open position. The auxiliary movable contact 13c provided, the bidirectional thyristor switch T connected between the main fixed contact 11 and the auxiliary fixed contact 12, and the thyristor switch at the moment when the main movable contact is separated from the main fixed contact during the opening operation. The thyristor switch is shut off before the auxiliary movable contact separates from the auxiliary fixed contact, and the thyristor switch is turned on after the auxiliary movable contact comes into contact with the auxiliary fixed contact during the closing operation so that the main movable contact becomes the main fixed contact. The thyristus after contact And a thyristor control circuit 18 for controlling the thyristor switch so as to cut off the pitch, the power supply 17 is connected via the load 16 between the main stationary contact and main movable contact.

In the present invention, the operation of the thyristor switch is confirmed by applying a voltage to the thyristor switch and applying a firing signal to the thyristor switch while the main movable contact is in contact with the main fixed contact. An operation check circuit 19 can be provided.

The operation check circuit 19 detects a current limiting resistor 20 having one end connected to the auxiliary fixed contact 12, a circuit for applying a power supply voltage to the thyristor switch through the current limiting resistor, and a current flowing through the thyristor switch. It can be constituted by the current detecting means 21 or a voltage detecting means for detecting a voltage between both ends of the thyristor switch.

The switch to which the present invention is directed is a disconnector,
This covers all power switches such as circuit breakers.

[0019]

With the above construction, the thyristor switch is disconnected from the main circuit when the switch is closed. Therefore, even when the switch is closed, a test voltage is applied to the thyristor switch to apply an ignition signal, thereby providing the thyristor switch. Operation can be confirmed.

As described above, according to the present invention, the operation of the thyristor switch can be checked at all times.
Failure to shut off the main circuit current due to a failure of the thyristor switch can be prevented.

[0021]

FIG. 1 shows a configuration of an embodiment of the present invention. In FIG. 1, a mechanical switch M is disposed at a position fixed to a main fixed contact 11 and a predetermined distance from the main fixed contact. The main fixed contact 1 includes an auxiliary fixed contact 12, a movable contact 13, and a current collecting contact 14 slidably contacting the movable contact 13.
1, the auxiliary fixed contact 12, and the current collecting contact 14 are arranged on the same axis with the auxiliary fixed contact 12 therebetween.

The main fixed contact 11 and the current collecting contact 14 are sliding contacts having a structure in which a number of contact pieces 11a and 14a arranged in a ring are urged radially inward by springs 11b and 14b, respectively. I have. Similarly, the auxiliary fixed contact 12 is also a sliding contact having a structure in which a large number of contact pieces 12a arranged in a ring are urged radially inward by a spring 12b. Is set sufficiently larger than the inner diameter of the main fixed contact 11. The contact pieces constituting these contacts are made of hard copper, and the surfaces thereof are silver-plated.

The movable contact 13 is a collecting contact 1
4, a tubular or rod-shaped movable conductor 13a supported in sliding contact, a main movable contact 13b connected to the tip of the movable conductor 13a and coming into contact with the main fixed contact from the inside, The auxiliary movable contact 13c has an enlarged diameter portion provided at a boundary between the conductor 13a and the conductor 13a. Auxiliary movable contact 13
Both ends of c are tapered so that the diameter gradually decreases toward the movable conductor 13a and the main movable contact 13b.

Movable conductor 13a and main fixed contact 13
The outer diameter of b is set to a size capable of contacting the main fixed contact 11 and the current collecting contact 14 with sufficient contact pressure, and the outer diameter of the auxiliary movable contact 13c is set to the auxiliary fixed contact 12 at a predetermined contact pressure. It is set to the size that can be touched. Since the inner diameter of the auxiliary fixed contact 12 is set to be sufficiently larger than the inner diameters of the main fixed contact 11 and the current collecting contact 14, when the movable conductor 13a and the main movable contact 13b are located inside the auxiliary fixed contact 12, A gap required for securing insulation between the auxiliary fixed contact 12 and the auxiliary fixed contact 12 is formed.

The movable contact 13 is connected to an operation device via an insulating operating rod (not shown), and a closed position where the main movable contact 13b contacts the main fixed contact 11 as shown in FIG. 2 (C). As the main fixed contact 1
1 and the auxiliary fixed contact 12 can be moved between an open position and a predetermined insulating distance.

The auxiliary movable contact 13c contacts the auxiliary fixed contact 12 immediately before the main movable contact 13b separates from the main fixed contact 11, and the main movable contact 1c
The position is set so that 3b moves away from the auxiliary fixed contact 12 before reaching the open position. Therefore, when the movable contact is in the closed position, the auxiliary movable contact 13c is located between the main fixed contact 11 and the auxiliary fixed contact 12, and when the movable contact 13 is in the open position, the auxiliary movable contact is connected to the auxiliary fixed contact 12 and the current collector. It is located between the contacts 14.

The thyristor switch T is composed of thyristors 15a and 15b connected in anti-parallel. This thyristor switch T conducts at the moment when the main movable contact is separated from the main fixed contact during the opening operation, and the auxiliary movable contact is auxiliary fixed. The thyristor control circuit 18 controls the thyristor control circuit 18 to shut off before leaving the contact, and to conduct after the auxiliary movable contact comes into contact with the auxiliary fixed contact during the closing operation, so that the main movable contact comes into contact with the main fixed contact. .

One end of an AC power supply 17 is connected to the main fixed contact 11, and a load 16 is connected between the other end of the power supply 17 and the current collecting contact 14.

In this embodiment, the main movable contact 13
In a closed state where b is in contact with the main fixed contact 11,
To confirm the operation of the thyristor switch T, one end of a current limiting resistor 20 is connected to the auxiliary fixed contact 12, and a power supply voltage is applied to the thyristor switch T via the current limiting resistor 20. Thyristor switch T and current limiting resistor 20
A current detecting means 21 comprising a current transformer is provided for detecting a current flowing through the thyristor switch T through the current limiting resistor 20, the current detecting means 21 and the current limiting resistor 20. And an operation check circuit 19 for detecting the operation of the thyristor switch T. Although not particularly shown, an inspection ignition signal supply circuit for appropriately supplying an inspection ignition signal to the thyristor switch T when the switch is closed is provided. The inspection firing signal supply circuit may be provided in the thyristor control circuit 18.

Next, the switching operation of the switch of the above embodiment will be described with reference to FIGS. As shown in FIG. 2A, in a state in which the main movable contact 13b contacts the main fixed contact 11 and the switch is closed, as shown by a broken line in FIG. The main circuit current flows through the path of the main movable contact 13b, the movable conductor 13a, the current collecting contact 14, the load 16, and the power supply 17. When the movable contact 13 is moved to the open position side to open the switch, the auxiliary movable contact 13c contacts the auxiliary fixed contact 12 immediately before the main movable contact 13b separates from the main fixed contact 11. Since the firing signal is given to the thyristor T before the main movable contact 13b separates from the main fixed contact 11, the thyristor switch T conducts at the moment when the main movable contact 13b separates from the main fixed contact 11, and FIG. The load current is commutated to the thyristor switch T as shown by the broken line in B). While the auxiliary movable contact 13c is in contact with the auxiliary fixed contact 12, the supply of the ignition signal to the thyristor switch T is stopped, and the thyristor switch T is turned off at the current zero point. Then, as shown in FIG. The auxiliary movable contact 13c is removed from the auxiliary fixed contact 12 as shown. Thus, the current can be cut off with almost no arc.

When the movable contact 13 is moved to the closed position to close the switch, the auxiliary movable contact 13c first comes into contact with the auxiliary fixed contact 12. At this time, the thyristor switch T is turned on while controlling the phase to start energizing the load with almost no arc. When the movable contact 13 further moves to the closed position side, the main movable contact 13b contacts the main fixed contact 11 while the auxiliary movable contact 13c keeps contact with the auxiliary fixed contact 12, and then the auxiliary movable contact 13
c moves away from the auxiliary fixed contact 12. As a result, the thyristor switch T is disconnected from the main circuit, and the thyristor switch is turned off.

In the above hybrid switch, FIG.
As shown in (A) and (B), the auxiliary movable contact 13c is separated from the auxiliary fixed contact 12 in the closed state and the open state, and the thyristor switch T is disconnected from the main circuit. Inspection of the thyristor switch T can be performed regardless of whether the vessel is in the closed state or the open state.

In order to inspect the thyristor switch T when the switch is in the closed state and when the switch is in the open state, an ignition signal is supplied to the thyristor switch T from an inspection ignition signal supply circuit (not shown). . If the thyristor switch T is normal, the thyristor switch T conducts when the inspection firing signal is given, and the thyristor switch T is turned on as shown by a broken line in FIG. 3A or 3B. The current of a predetermined magnitude flows through the current limiting resistor 20 and the current limiting resistor 20. Therefore, every time a firing signal for inspection is supplied to the thyristor switch T, the current flowing through the thyristor switch T and the current limiting resistor 20 is detected by the current detecting means 21 and the detected value is compared with a reference value to thereby provide a thyristor switch. It is possible to detect whether T is sound or not. If a firing signal for inspection is automatically supplied to the thyristor switch T at a predetermined time interval and the current supplied to the thyristor switch is automatically detected each time the firing signal is applied, the thyristor switch T Inspection can be performed automatically.

When the thyristor switch T is turned on, the voltage across the thyristor T drops to a voltage corresponding to a forward voltage drop between the anode and cathode of the thyristor.
Instead of providing the current detecting means 21 as in the above embodiment, a voltage detecting means for detecting the voltage between both ends of the thyristor switch T can be provided, and the operation of the thyristor switch T can be confirmed by the voltage detecting means.

In the above embodiment, the current detecting means 21 comprising a current transformer is provided, and the current flowing through the thyristor T is detected by the current detecting means. By detecting the current, the current flowing through the thyristor T may be detected.

In the above embodiment, the auxiliary fixed contact 1
2 is disposed between the main fixed contact 11 and the current collecting contact 14, but as shown in FIGS. 4A to 4C, the main fixed contact 12 is disposed between the auxiliary fixed contact 12 and the current collecting contact 14. 11 may be arranged. In this case, an auxiliary movable contact 13c is formed at the tip of the movable contact 13, and the auxiliary movable contact 13c and the main movable contact 13b are connected via a small-diameter connecting portion 13d. The auxiliary movable contact 13c contacts the auxiliary fixed contact 12 immediately before the main movable contact 13b separates from the main fixed contact 11, and the auxiliary movable contact 13c separates from the auxiliary fixed contact 12 before the main movable contact 13b reaches the open position. The point that the positional relationship of each part is set is the same as in the above-described embodiment, and the manner of controlling the thyristor switch T is completely the same as in the above-described embodiment. 4 (A) to 4 (C)
Indicates a closed state, a halfway open state, and an open state of the switch, respectively.

In each of the above embodiments, the movable contact 13
The current collecting contact 14 is brought into contact with the movable contact to an external circuit through the current collecting contact, but a flexible conductor such as a braided wire is used without using the current collecting contact. The movable contact 13 may be connected to an external circuit through the flexible conductor by connecting to the movable conductor 13a.

In the above embodiment, the main movable contact 13
Although b is brought into sliding contact with the main fixed contact 11, the main movable contact 13b and the main fixed contact 11 may be brought into abutting contact with each other.

FIG. 5 shows an embodiment in which the main movable contact 13b and the main fixed contact 11 are brought into abutting contact with each other. In this embodiment, the main fixed contact 11 is formed in an annular shape. The main fixed contact is supported by an annular conductive block 22 via a contact spring 23, and the main fixed contact 11 is a flexible conductor 24.
Are connected to the conductive block 22 via the.

The main movable contact 13b is formed in a disk shape, and the main movable contact 13b is
Butt contact. The auxiliary movable contact 13c and the auxiliary fixed contact 12 are configured in the same manner as the embodiment of FIG. 4, and when the circuit is opened, the auxiliary movable contact 13c contacts the auxiliary fixed contact 12 immediately before the main movable contact 13b separates from the main fixed contact 11. And the main movable contact 13b is
The auxiliary movable contact 13c separates from the auxiliary fixed contact 12 after moving away from the main movable contact 1 when the circuit is closed.
The auxiliary movable contact 13c contacts the auxiliary fixed contact 12 before the 3b contacts the main fixed contact 11, the main movable contact 13b contacts the main fixed contact 11, and then the auxiliary movable contact 13c separates from the auxiliary fixed contact 12. The positional relationship of each part is set. The thyristor switch T is connected between the conductive block 22 and the auxiliary fixed contact 12.

In each of the above embodiments, the movable contact 13
Is linearly displaced, but the movable contact may be configured to be rotationally displaced along an arc-shaped trajectory.

In the above description, a switch of a single-phase circuit is taken as an example, but the present invention can of course be applied to a hybrid switch of opening and closing a three-phase circuit.

[0043]

As described above, according to the present invention, even when the switch is opened, the auxiliary movable contact is separated from the auxiliary fixed contact, and the thyristor switch is disconnected from the main circuit. In any of the closed state and the closed state, the operation of the thyristor switch can be confirmed by applying a test voltage to the thyristor switch and giving an ignition signal. Therefore, it is possible to prevent a failure in shutting off the main circuit current due to a failure of the thyristor switch beforehand, and to improve the reliability of the hybrid switch.

[Brief description of the drawings]

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

2 (A) to 2 (C) are schematic configuration diagrams showing an open state, a halfway open state, and a closed state of the switch of the embodiment of FIG. 1, respectively.

FIGS. 3A and 3B are explanatory diagrams showing a state in which the operation of the thyristor switch is checked in the closed state and the open state of the switch of the embodiment of FIG. 1, respectively.

FIGS. 4A to 4C are schematic configuration diagrams showing an open state, a state during opening and closing, and a closed state, respectively, of another embodiment of the present invention.

FIG. 5 is a schematic configuration diagram showing another embodiment of the present invention.

FIG. 6 is a configuration diagram showing a configuration of a conventional hybrid switch.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Main fixed contact 12 Auxiliary fixed contact 13 Movable contact 13a Movable conductor 13b Main movable contact 13c Auxiliary movable contact 14 Current collecting contact 15a, 15b Thyristor 16 Load 17 AC power supply 18 Thyristor control circuit 19 Operation check circuit 20 Current limiting resistor 21 Current detection means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-240015 (JP, A) JP-A-61-109217 (JP, A) JP-A-3-129614 (JP, A) 54174 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01H 33/59 H01H 33/12 H01H 9/54 H01H 9/00

Claims (3)

(57) [Claims] 1. A main fixed contact, an auxiliary fixed contact, and a displaceable position between a closed position in contact with the main fixed contact and an open position at a predetermined insulating distance from the main fixed contact. The main movable contact is integrated with the main movable contact, the main movable contact comes into contact with the auxiliary fixed contact immediately before leaving the main fixed contact, and the auxiliary fixed contact comes before the main movable contact reaches the open position. An auxiliary movable contact provided so as to be away from the main fixed contact and a bidirectional thyristor switch connected between the main fixed contact and the auxiliary fixed contact; and at the moment when the main movable contact separates from the main fixed contact during an open circuit operation. When the thyristor switch is turned on, the auxiliary movable contact becomes an auxiliary fixed contact. The thyristor switch is turned off before leaving the thyristor switch, and during the closing operation, the thyristor switch is turned on after the auxiliary movable contact comes into contact with the auxiliary fixed contact, and the thyristor switch is turned off after the main movable contact comes into contact with the main fixed contact. And a thyristor control circuit for controlling the thyristor switch so as to cause the power supply to be connected between the main fixed contact and the main movable contact via a load. 2. An operation of confirming the operation of the thyristor switch by applying a voltage to the thyristor switch and applying a firing signal to the thyristor switch while the main movable contact is in contact with the main fixed contact. The hybrid switch according to claim 1, further comprising a confirmation circuit. 3. An operation check circuit comprising: a current limiting resistor having one end connected to the auxiliary fixed contact; a circuit for applying a power supply voltage to the thyristor switch through the current limiting resistor; and a current flowing through the thyristor switch. 3. The hybrid switch according to claim 2, further comprising a current detecting means for detecting the voltage, or a voltage detecting means for detecting a voltage between both ends of the thyristor switch.