JPH08237828A - Grounding switchgear - Google Patents

Abstract

PURPOSE: To provide a grounding switchgear which is provided with a fixed contact and a moving contact having a current capacity and a withstand voltage which are sufficient to ground a high-voltage and large-current main circuit apparatus, in which a slit-shaped opening part is formed at one end of the moving contact, in which a thrust bearing and a bevel gear are installed at the other end of the moving contact and which is opened and closed stably while its tip is not swung. CONSTITUTION: A fixed contact 31 which is composed of a tulip-shaped contact part and a moving contact 32 form a pair, and they supply and disconnect a current. While the moving contact 32 which is cylindrical is being brought into sliding contact with a collector 34 electrically, it is driven mechanically by a shaft 37, a rotation-to-linear motion conversion device 38 such as a ball screw or the like, a bevel gear 40, an electric motor 42 and the like so as to perform a linear motion. The side of the fixed contact 31 of a main circuit conductor 45 and the side of the moving contact 32 on the ground side are insulated and supported by an insulating tube 35, and they are fixed by a base 36 fixed to the main circuit conductor 45 and by a fixation metal fitting 47 on the ground side. The bevel gear 40 is housed inside a gear box 41, and it is controlled by a control box 44. Thereby, it is possible to effectively prevent the tip of the shaft 37 from being swung.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a generator for power supply and grounding of a main circuit directly connected to the generator, and an electric brake for braking for starting and stopping the generator of a pumped storage power plant. The present invention relates to a voltage circuit switchgear.

[0002]

2. Description of the Related Art Conventionally, a grounding switch attached to a main circuit breaker or a main circuit disconnector is used for grounding an AC generator for power supply, a phase-separated insulating busbar directly connected to the AC generator, and a main circuit breaker. Although there were many cases, it was difficult to systematically ground the system, so it is necessary to systematically ground the phase-separated insulation busbars that are directly connected to the main circuit grounding during maintenance and inspection of the generator and its directly connected devices. In such cases, a grounding switch having a single-pole / single-throw structure as shown in FIG. 1 was used.

Further, in connection with the recent tight demand for electric power,
At pumped storage power plants, etc., frequent start-stops are required several times a day, and when stopping the alternator, electric brakes are often used together before mechanical braking. There is. In such a case, a three-phase integrated switch in which three poles are interlocked is desirable, and an electric brake switch as shown in FIG. 7 has been used.

In FIG. 1, 1 is a fixed contact, 2 is a movable contact, the fixed contact 1 is fixed to a base 6, and the movable contact 2 is fixed to a cylindrical movable contact support 3. The movable contactor support base 3 is driven by a drive motor 12 or a manual operation unit 13 via a rotary shaft 7, a rotary-linear motion conversion device 8, a support bearing 18, a gear 10, etc., and is guided by a guide 9 to collect current. The movable contactor 2 is opened and closed while sliding. 11 is a gear box, 14 is a control unit, 1
Reference numeral 5 is a main circuit conductor, 16 is a sheath for the main circuit conductor, 17 is a flange formed by processing a part of the sheath, 19 is a ground side terminal, and the base 6 and the ground side terminal 19 are electrically connected by the insulating cylinder 5. Insulated.

In FIG. 7, reference numeral 71 is a main contact, 72 is an arc contact, and 73 is an insulating operation rod, which is driven by a drive motor 76 or a manual operation mechanism 79 to perform an opening / closing motion.
74 is an insulating rod between main circuit poles, 75 is an insulating stand between grounds, 77 is an upper terminal, 78 is a lower terminal, 80 is a main circuit cover,
Reference numeral 81 is an inspection window, and 82 is an operation section door. As a technique having a grounding switch, there is JP-A-60-51401.

[0006]

Problems to be Solved by the Invention FIGS. 8 (a) and 9
(A) shows an explanatory view of the main parts of the circuit used for the electric brake switch and the ground switch. G is a generator, CB is a main circuit breaker,
TR is a transformer, and when stopping the generator G, it is advisable to open the main circuit breaker CB and close the switch S _{1 so} that a current having a phase different from the generator-generated current can flow from another power supply V. As the most straightforward example, an example of antiphase is shown in FIG.

[0007]

## EQU1 ## Ia '= Ia, Ib' = Ib, Ic '= Ic (Equation 1) In such a case, the switch for electric brake shown in FIG. 7 is used as the switch S ₁ . However, this method requires a separate power source V, and the switch used is large in size and has a large dielectric strength against ground, and the installation area is large. Even if the switch S ₂ is closed and the three phases are short-circuited instead of using a separate power source, and the three phases are collectively grounded, a force for braking the rotating generator G can be obtained. An example thereof is shown in FIG.

The three-phase currents of the generator G are respectively Ia and I
If b and Ic,

[0009]

[Equation 2] Ia + Ib + Ic = 0 (Equation 2), which is electrically equivalent even if the three phases are grounded together, and from Equation (2),

[0010]

Equation 3] _{I 2 = (Ib + Ic)} ... The Since it is clear that becomes (number 3), comparable braking force applied opposite phases are obtained. E in FIG. 9A indicates ground. In such a case, a relatively small-sized single-pole grounding switch shown in FIG. 1 is used as the switch S ₂ , but the tip of the movable contact is also easily shaken in this grounding switch, and three-phase batch drive is not possible. There were some difficulties.

[0011]

Since the switch does not require ground insulation, the three-phase collective grounding method shown in FIG. 9 (a) can be made smaller than the separate power supply method shown in FIG. 8 (a). Obviously, the grounded switch shown in FIG. 1 has a problem as described above. One of them is the runout of the tip of the movable contactor. As shown in FIG. 1, the movable contactor support base 3 is a movable contactor that makes electrical sliding contact with the current collector 4 attached to a part of the ground-side terminal 19. It forms a part and is made of a conductive tubular metal in order to increase the current carrying capacity. In this case, since the rotary shaft 7 is guided only by the support bearing 18 at one end, the movable contact support base 3 is fixed. When moving to the contactor 1 side, the tip of the rotary shaft 7 swings by 0 degrees from the centerline of rotation as shown in FIG. 2, and as a result, the movable contactor 2 and the fixed contactor 1 are moved.
There was a risk that the joints would not be joined correctly. The current collector 4 that is in sliding contact with the movable contact support base 3 is itself displaced by a spring, and cannot positionally support the tip of the movable contact support base 3 after movement. Therefore, in the present invention, as shown in FIGS. 3 and 4, the movable contact 32 is provided with the opening 33 while keeping the current carrying capacity necessary and sufficient, and the support base 48 of the thrust shaft 49 is not separated from the opening 33. The tip end portion 50 of the rotating shaft 37 is rotatably supported and fixed by the thrust bearing 49.

Another difficulty of the conventional grounding switch shown in FIG. 1 is that it is difficult when a three-phase one-piece structure is desired or when it is desired to drive all three-phases by a single electric motor. I had to make or buy a vessel. FIG. 5 (a) shows an explanatory view of a main part structure when the manual operation part 13 of the conventional grounding switch shown in FIG. In S _1, S _2, S ₃ are three expressions of the grounding switch, is driven by an electric motor M, in addition to the length of the connecting direction becomes longer, switches S _1, of S ₂ of the rotating shaft When the rotation direction is positive, the rotation direction of the switch S ₂ is opposite, and in order to match the moving direction of the movable contactor, it is necessary to use a reverse screw in which the screw shaft of the switch S ₂ is reversed in screw direction. There were some difficulties, such as some. FIG. 5B is an explanatory view of a main part structure for solving this point. For comparison, the electric motor M is at the same position, but the height of the connecting gear directly connected to the rotating shaft is sufficiently low. Then, a manual operation part configured to be connectable to the connecting fitting and a connecting shaft having a connecting part at the other end are integrally formed, and the connecting shaft is passed directly underneath in a form orthogonal to the rotating shaft gear. By connecting the connecting shafts with a linear connecting metal fitting, it is possible to obtain a three-phase integrated grounding switch whose rotation directions are the same.

Further, according to the present invention, as shown in FIG. 6, the electric motor 42 can be attached to the gear box of any switch in such a manner that it is orthogonal to both the rotating shaft 37 and the connecting shaft of the switch and the connecting fitting 64. Therefore, in addition to being able to shorten the lengthwise dimension, by connecting switches with exactly the same structure, it is possible to obtain a multi-phase batch grounding switch.

[0014]

[Operation] The basic single-pole grounding switch has a fixed and movable contactor that has sufficient current capacity and withstand voltage to ground high-voltage, high-current main circuit equipment such as a generator for the purpose of maintenance. ,
Since the cylindrical movable contactor 32 has a slit-shaped opening 33 on one side surface thereof and is linearly driven by a rotating shaft 37 whose tip 50 is rotatably supported by a thrust bearing 49,
It is possible to reliably bring the fixed contactor 31 into and out of contact with the fixed contactor 31 by a stable linear motion with no precession.

Further, the rotating shaft 37 also has the height of the connecting bevel gear 40 in the gear box 41 sufficiently lowered so that the connecting fitting 64
And a connecting shaft 66 having a connecting portion 47 at the other end are integrally formed, and the connecting shaft 66 is orthogonal to the rotating shaft bevel gear 40 and passes directly below the connecting shaft 66 to connect the connecting shaft 66 and the rotary shaft bevel gear 40. By connecting the shafts 66 with the linear connecting metal fittings 64, it is possible to obtain a multi-phase collective grounding switch in which the rotating shafts 37 rotate in the same direction, and the drive motor 47 is connected to one end of the gear box 41. Since it is configured so that it can be installed in any switch with the opening of the switch being orthogonal to the rotating shaft and the connecting shaft 66, the length can be shortened and a plurality of switches of the same structure can be used. As a result, it is possible to obtain a multi-phase earthing switch which is driven by a single electric motor in a multi-phase collective form.

[0016]

Embodiments (a) and (b) of FIG. 3 are a front view and a side view, in which an insulating cylinder, a fixed contactor, etc. of a grounding switch for a generator of the present invention are partially broken to explain the structure. In the figure, 31 is a fixed contactor including a tulip-shaped contact portion, and the movable contactor 3
Pairs with 2 and participates in energization and disconnection of electric current. The cylindrical movable contactor 32 is in sliding contact with the current collector 34 electrically, and mechanically, the rotary shaft 37, a rotary linear motion conversion device 38 such as a ball screw, a bevel gear 40, an electric motor 42, and the like. Drives linear motion. Reference numeral 35 denotes an insulating tube that electrically insulates the main circuit conductor 45, that is, the fixed contact 31 side and the ground side, that is, the movable contact 32 side, and is fixed to the main circuit conductor and the base 36 and the fixing fitting 47 of the ground side terminal. It is fixed by. Reference numeral 39 is a detent guide for the rotary straight-line motion conversion device, 41 is a gear box, 43 is a manual operation unit used in case of emergency or maintenance, and 44 is a control box.

FIG. 4 illustrates the relationship between the main parts that support the tip of the rotary shaft 37 of the grounding switch of the present invention. 49 is the rotating shaft 3
7 is a thrust bearing for rotatably supporting the tip 50 of the 7, and the thrust bearing 49 passes through the slit-shaped opening 33 provided in the cylindrical movable contact 32 and the thrust bearing support 48 causes the ground-side terminal block 46. The movable contact 33 is fixed to the rotary shaft 37 so that the rotary shaft 37 can be prevented from swinging and a stable linear motion of the movable contact 33 can be achieved. Of course, the movable contact 33
Also, the current collector 34 and the fixed contactor 31, which are in sliding contact with the movable contactor, and the sliding portion have an effective area sufficient for energization except for the opening. Further, in consideration of economy, FIG. 3 shows an example in which a cylindrical movable contactor is used. However, the cylindrical movable contactor is used as a movable contactor support base and has a finger shape as shown in FIG. The movable contactor 2 can be attached to the tip of the movable contactor support base 3.

This device is based on a unipolar structure as shown in FIGS. 3 (a), (b) and FIG. 4, but in terms of control, etc.
In some cases, it is desired to perform the opening / closing operation with a single drive motor in the three-phase collective type. FIG. 5 (b) is a structural explanatory diagram of the main parts of the three-phase collective type, and FIG. 6 is the three-phase collective type of the present invention. The side view of a grounding switch is shown. S ₁ , S ₂ , and S _{3 are} switches having a single-pole structure, and each of them is connected to a connecting portion 47 and a manual operation portion 43 which also serves as a connecting portion by a connecting metal fitting 64 and is orthogonal to the connecting shaft 66. It is driven by a single electric motor 42 attached to the gear box of the switch, and opens and closes via a rotating shaft 37. Reference numerals 61 and 62 denote a separating bus insulating bus and a sheath connected to the generator. When the switch is closed, the phase separating insulating bus 61 is short-circuited by the short-circuit plate 65 in three phases. Reference numeral 63 is a flange for attaching the switches S ₁ , S ₂ , S ₃ to the phase-separating busbar 61, which is connected to the main circuit conductor 45. Switch S
₁ is located at the end, so a cover is attached to the connecting portion 47, except that the switch S ₂ is located in the center and one end face of the gear box 41 is opened and the drive motor 42 is attached. For example, the switches S ₁ , S ₂ , and S ₃ have exactly the same structure, and the rotating shaft 37 rotates in the same direction. Although the example of driving by one electric motor is shown in the explanation example of FIG. 5B and the embodiment of FIG. 6, each switch S ₁ , S ₂ , S remains the switch of single pole structure. ₃ it is also possible to three-phase connection while retaining a respective drive motor. In this case, the switches S ₁ , S ₂ , S ₃ perform the switching operation only in electrical synchronization.

Further, in FIG. 5 (b), in order to make the configuration easy to understand, an explanation has been given with an electric motor at one end and a manual operation part at the other end, but in the embodiment, as shown in FIG. The electric motor 42 is orthogonal to the connecting shaft 66 and can be attached to any of the switches.
Since it can be used as a manual operation unit, it is possible to provide a manual operation unit at both left and right ends.

[0020]

EFFECTS OF THE INVENTION Since the grounding switchgear of the present invention is constructed in this way, (1) it is possible to effectively prevent the tip end deflection of the rotating shaft 37, and the movable linear contact 32 can be smoothly moved linearly. Movable contact 3
It is possible to obtain a reliable fitting contact between the stationary contactor 31 and the fixed contactor 2.

(2) A bevel gear in which a linear movement shaft of the movable contactor 32 and a rotation shaft of the drive motor 42 are orthogonal to each other and a connecting shaft 66 having a manual operation portion 43 at the other end is directly connected to the rotating shaft 37. By providing it just below 40, the dimensions are reduced three-dimensionally, and the switches can be connected to each other.

(3) The manual operation part 43 configured to be connected to the connecting fitting 64 and the connecting part 47 at the other end are connected to the connecting shaft 6.
6 is integrally formed, and by connecting the connecting shaft 66 with the connecting metal fitting 64, the single-phase earthing switches having the same structure in the same rotating direction can be assembled to obtain a multi-pole earthing switch. There are numerous manufacturing and maintenance advantages.

(4) The multi-pole grounding switch thus obtained may be provided with the electric motor provided in each single-phase earthing switch as it is, or a single electric motor depending on the number of switches. Since it can be mounted on a switch and driven, it offers great advantages to both manufacturers and users, such as simultaneous maintenance with a single motor and improved maintainability.

[Brief description of drawings]

FIG. 1 is a side view of an insulating cylinder or the like of a conventional grounding switch.

FIG. 2 is an explanatory diagram showing an eccentric state of a rotary shaft and a movable contact of the conventional grounding switch shown in FIG.

FIG. 3 is an explanatory view of the ground breaker of the present invention, which is partially broken.

FIG. 4 is an explanatory view of a tip end support of a rotating shaft of the grounding switch of the present invention.

FIG. 5 is an explanatory diagram of a main part for a configuration comparison when a three-phase collective type is formed.

FIG. 6 is a side view of a three-phase collective grounding switchgear according to the present invention.

FIG. 7 is an explanatory diagram of a conventional three-phase collective switch.

FIG. 8 is an explanatory diagram of an electric brake circuit of another power supply system.

FIG. 9 is an explanatory diagram of a grounding type electric brake circuit.

[Explanation of symbols]

31 ... Fixed contactor, 32 ... Movable contactor, 33 ... Movable contactor opening, 34 ... Current collector, 35 ... Insulating cylinder, 36 ... Base, 37 ... Rotating shaft, 38 ... Rotation straight line motion conversion device, 4
0 ... Bevel gear, 41 ... Gear box, 42 ... Drive motor,
43 ... Manual operation part, 44 ... Control box, 45
... main circuit conductor, 46 ... ground side terminal block, 48 ... thrust bearing support block, 64 ... coupling fitting, 66 ... coupling shaft.

Claims (4)

[Claims] 1. A pair of movable contacts and a fixed contact, which are driven by an electric motor or manually to perform an opening / closing operation via a gear train, a rotary motion-linear motion converter, and a movable side and a fixed side are electrically connected. In an opening / closing device having an insulating cylinder or an insulating rod for insulating and supporting, a gear of a rotary shaft for driving the movable contact is provided with an opening having a length corresponding to the stroke length in a part of the cylindrical movable contact. A grounding opening and closing, characterized in that a removable fixing device for rotatably fixing the other end of the connection is provided at the other end of the gear connection so that a smooth linear opening / closing operation of the movable contact can be obtained. apparatus. 2. The electric motor rotating shaft according to claim 1, wherein the electric motor rotating shaft is provided orthogonal to the linear moving shaft of the movable contactor, and the other end is arranged so as to be orthogonal to the linear moving shaft of the movable contactor and the electric motor rotating shaft. A grounding switchgear that has a connecting shaft with a manual operation part on its side to reduce the three-dimensional size and enables mutual connection. 3. A linear movement axis of a movable contact orthogonal to each other, an electric motor rotation axis, and a connecting axis having a manual operating portion at the other end, so that a manual operating tool such as a handle can be easily connected. At the same time, a manual operation part configured to be able to be connected to the connection fitting using the manual operation part and a connection shaft having a connection part at the other end are integrally formed, and the connection shaft is connected by a linear connection fitting. The grounding switchgear is a collection of single-phase grounding switches with the same structure that rotate in the same direction so that a multi-phase grounding switch can be obtained. 4. The movable contact linear movement axis orthogonal to the ratchet according to claim 3, a motor rotation axis, and a connecting shaft having connecting portions at both ends, wherein the connecting shaft is connected by a connecting metal fitting. In the multi-phase ground switch obtained by, the electric motor that drives the movable contactor may have its own motor attached to each ground switch, and the electric motor having the capacity corresponding to the number of the ground switches that are assembled. An installation switchgear that can be driven by one unit, and that one electric motor can be installed on any grounding switch of the assembled grounding switches.