JP6070313B2 - Energy storage device for tap changer when loaded - Google Patents

Description

  The present invention relates to an energy storage device used for a switching switch of a load tap changer.

  The transformer load tap changer is a device that switches taps during transformer operation (loading), and switches the tap selector to select the tap to be operated by the transformer tap winding and the circuit to the selected tap. It is comprised from a switching switch (for example, nonpatent literature 1).

  The switching switch needs to be operated at high speed in order to switch the odd-numbered tap and the even-numbered tap in the energized state. Therefore, a storage device is provided in the switching switch. The energy storage device stores the force in the spring by compressing or extending the spring, and operates the switching switch by releasing the energy stored in the spring.

  In the accumulator of the switching switch, a linear operation mechanism (for example, Non-Patent Document 2) that converts a linear operation into a rotation operation of the switching switch by operating a spring linearly, There is a rotary operation mechanism (for example, Patent Document 1 and Non-Patent Document 3) in which a spring is provided on a lever directly connected to a drive shaft, and the lever is directly moved in a circular arc by storing and releasing the spring.

Japanese Patent Laid-Open No. 11-238635

Yukinobu Higuchi, 2 others, “Vacuum valve type tap changer for oil-filled transformers”, Toshiba review, 2001, Vol. 56, no. 10, p. 52-55 "FK Series M-Type Tap Switch at Load", Toshiba Catalog, Toshiba Corporation, 1984, KSA-37019, 1984-5 (1) "LJND-400R type tap changer at load", instruction manual, Meidensha, 1990, RM9011A

  Since the rotational operation mechanism has a relatively simple structure, it is considered that problems in the energy storage device are less likely to occur compared to the linear operation mechanism.

  However, in the rotating mechanism, the lever starts to move from a point where the spring operating point and the central axis of the lever exceed a point (dead point) that becomes a straight line. At this point, the line of action of the spring force and the center of the lever The angle formed by the shaft is small, and the rotational torque of the lever due to the spring force is small. Therefore, the initial speed is reduced in the operation of the switching switch.

  For example, in the on-load tap switching device (see Non-Patent Document 1) that switches circuits using a vacuum valve (VI) type switching circuit system, as shown in FIG. ), The vacuum valves V1 and V2 are switched (3 → 4 in the figure), and the switch S is switched (4 → 5 in the figure). That is, the vacuum valves V1 and V2 are switched before the switch S is switched. However, when the initial speed of operation of the switching switch is small, there is a possibility that normal current interruption and closing are hindered.

  In view of the above circumstances, an object of the present invention is to provide a technique that contributes to improving the stability of the operation of switching the switch of the on-load tap switching device.

  An energy storage device for an on-load tap switching device according to the present invention that achieves the above object is an energy storage device for an on-load tap switching device that switches a circuit in accordance with rotation of an output shaft, and one end of the energy storage device is fixed to the output shaft. Main lever, one end pivotally supported by the output shaft, an auxiliary lever for controlling the operation of the main lever, and a main spring provided between the other end of the main lever and the other end of the auxiliary lever And an auxiliary spring that is provided at the other end of the main lever and pulls the main lever to the center of the operating range of the main lever, and is locked in a locking groove formed at one end of the main lever. And a stopper for temporarily limiting the rotation of the main lever.

  ADVANTAGE OF THE INVENTION According to this invention, it can contribute to the stability improvement of the operation | movement which switches the switch of the tap switching apparatus at the time of a load.

It is a figure which shows the outline of the energy storage apparatus of the tap switching apparatus at the time of load which concerns on embodiment of this invention. It is a top view of the energy storage device of the on-load tap switching device according to the embodiment of the present invention. It is explanatory drawing explaining operation | movement of the energy storage apparatus which concerns on embodiment. It is explanatory drawing explaining the output-shaft operating torque which acts on a main lever. It is explanatory drawing explaining the operation | movement sequence which switches a switching switch. It is explanatory drawing explaining the circuit switching operation | movement of the tap switching apparatus at the time of switching a circuit by the switching circuit system of a vacuum valve (VI) type.

  An energy storage device of a load tap switching device according to an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing an outline of an energy storage device 1 of an on-load tap switching device according to an embodiment of the present invention. FIG. 2 is a top view of the energy storage device 1 of the on-load tap switching device according to the embodiment of the present invention.

  As shown in FIG. 1, the energy storage device 1 includes an output shaft 2, a main lever 3 that is fixed to the output shaft 2 and can be swung, a drive unit 4 that drives the main lever 3, and the main lever 3. An auxiliary spring 5 for braking and a stopper 6 for temporarily limiting the rotation of the main lever 3 are provided.

  The output shaft 2 is connected to a drive unit (not shown) that drives a change-over switch (and a vacuum valve) in a change-over switch (not shown), and in conjunction with the rotation of the output shaft 2, the change-over switch Switching takes place.

  One end of the main lever 3 is fixed to the output shaft 2. A main spring 8 and an auxiliary spring 5, which will be described in detail later, are provided at the other end of the main lever 3 (hereinafter referred to as the tip). A contact plate (not shown) is provided in each swing direction of the main lever 3, and the swing range of the main lever 3 is limited by the contact plate. Further, locking grooves 3a that are locked by the stoppers 6 are formed in the respective swinging directions at the end portions (hereinafter referred to as shaft end portions) of the main lever 3 that are fixed to the output shaft 2.

  The drive unit 4 includes an auxiliary lever 7 that is rotatably provided on the output shaft 2, a main spring 8, and a drive lever 9.

  One end of the auxiliary lever 7 is rotatably supported by the output shaft 2. A main spring 8 and a link 10 are provided at the other end of the auxiliary lever 7 (hereinafter referred to as the tip). The movement of the drive lever 9 is transmitted to the auxiliary lever 7 by the link 10. A protrusion 7 a is provided on the surface of the auxiliary lever 7 facing the main lever 3, and the protrusion 7 a pushes the stopper 6 in accordance with the rotation of the auxiliary lever 7, so that the stopper 6 It comes off from the locking groove 3a (the stopper 6 is released).

  The main spring 8 is, for example, a tension spring, and one end is fixed to the tip of the main lever 3 and the other end is fixed to the tip of the auxiliary lever 7. Although FIG. 1 illustrates an example in which two main springs 8 are provided, the number of main springs 8 may be set as necessary.

  The drive lever 9 is a lever whose one end is pivotally supported on the rotation shaft. For example, when the drive lever 9 is operated by a worm gear 11 driven by an operating mechanism (not shown) (not shown), the drive lever 9 is connected to the worm wheel of the worm gear 11. A link 10 is provided at the other end of the drive lever 9, and the auxiliary lever 7 rotates (swings) according to the rotational movement of the drive lever 9.

  The auxiliary spring 5 is attached so as to pull the main lever 3 toward the center of the operating range. For example, one end of the auxiliary spring 5 is fixed to the tip of the main lever 3, the other end of the auxiliary spring 5 is on the bisector of the swing angle of the main lever 3, and the length of the main lever 3 from the output shaft 2. It is fixed at a position farther away.

  The stopper 6 is rotatably supported at one end and is provided in a state where the other end is in contact with the shaft end of the main lever 3 by a biasing member (spring or the like) not shown. A pair of stoppers 6 are provided for each swinging direction of the main lever 3 to temporarily limit the rotation of the main lever 3. In a state where the main lever 3 is stopped, the stopper 6 engages with a locking groove 3 a formed in a direction in which the main lever 3 can move, and restricts the movement of the main lever 3.

  Next, with reference to FIG. 3, operation | movement of the energy storage apparatus 1 which concerns on embodiment is demonstrated. In addition, description of the main spring 8 and the auxiliary spring 5 is abbreviate | omitted in FIG.3 (b)-FIG.3 (g).

  Fig.3 (a) is a figure which shows the time of the start of the switching operation | movement of an on-load tap switching device. When the drive lever 9 is rotated (rotated counterclockwise) by the worm gear 11, the auxiliary lever 7 is rotated (rotated counterclockwise). At this time, the main lever 3 is pulled counterclockwise by the main spring 8 and pulled clockwise by the auxiliary spring 5. Since the force that the main spring 8 pulls the main lever 3 is larger than the force that the auxiliary spring 5 pulls the main lever 3, the main lever 3 is pressed in the direction of the contact plate (not shown) (moved from the initial position). Not). The stopper 6 is pressed in the direction of the main lever 3 and is locked in the locking groove 3 a of the main lever 3.

  As shown in FIGS. 3B and 3C, the auxiliary lever 7 also rotates in accordance with the rotation of the drive lever 9. By rotating the auxiliary lever 7, the distance between the distal end portion of the main lever 3 and the distal end portion of the auxiliary lever 7 is increased, and elastic energy is accumulated in the main spring 8. During this time, tap selection by a tap selector (not shown) is performed according to the rotation of the worm wheel of the worm gear 11.

  As shown in FIG. 3D, when the angle formed between the auxiliary lever 7 and the main lever 3 is 180 °, the main spring 8 is in the most extended state. At this time, the main lever 3 is pulled in the clockwise direction by the auxiliary spring 5, but the main lever 3 does not move from the initial position because the stopper 6 is locked in the locking groove 3a.

  As shown in FIG. 3E, when the auxiliary lever 7 further rotates, the protrusion 7a of the auxiliary lever 7 hits the stopper 6, and the stopper 6 comes off the locking groove 3a. When the stopper 6 is released, the main lever 3 rotates clockwise by the elastic energy accumulated in the main spring 8 and the auxiliary spring 5 (FIG. 3 (f)). At this time, the main lever 3 moves instantaneously until it hits a contact plate (not shown) that restricts the rotational movement in the clockwise direction. And even after the main lever 3 hits against the contact plate and stops, the drive lever 9 continues to move, and stops when it moves 180 ° from the initial position (FIG. 3G).

  Here, the output shaft operating torque acting on the main lever 3 will be described in detail with reference to FIG. Since the main spring 8 and the auxiliary spring 5 are provided at the distal end portion of the main lever 3, the output shaft operating torque is a resultant force of the main shaft operating torque by the main spring 8 and the main shaft operating torque by the auxiliary spring 5. In FIG. 4, the angle at the start of rotation of the main lever 3 is 0 ° and the angle at the stop is 70 °. However, the angle at which the main lever 3 is driven is not limited to this angle. FIG. 4 shows the change in torque with respect to the operating angle of the main lever 3, and detailed numerical values of torque on the vertical axis are omitted.

  The main spring 8 is in a state where the operation start time of the main lever 3 is most extended (elastic energy is stored most), and is contracted according to the operation of the main lever 3. Therefore, the elastic force of the main spring 8 is the largest at the start of operation of the main lever 3 and decreases as the main lever 3 operates. However, as shown in FIG. 4 (a), the output shaft operating torque depends on the angle between the direction in which the elastic force of the main spring 8 acts and the direction in which the main lever 3 rotates. It is the smallest and increases as the operating angle of the main lever 3 increases.

  On the other hand, the auxiliary spring 5 is in a state where the operation start point of the main lever 3 is most extended (elastic energy is stored most), is in a state where it is most contracted at an intermediate point, and is again extended most when the main lever 3 is stopped. It becomes a state. That is, the elastic force (absolute value) of the auxiliary spring 5 becomes maximum at the start point and end point of the operation of the main lever 3 and becomes minimum at the intermediate point. As a result, as shown in FIG. 4B, the output shaft operating torque by the auxiliary spring 5 becomes maximum at the start of the operation of the main lever 3, becomes 0 at the intermediate point, and thereafter becomes minus (movement of the main lever 3). Torque).

  When the resultant force of the output shaft operating torque by the main spring 8 shown in FIG. 4 (a) and the output shaft operating torque by the auxiliary spring 5 shown in FIG. 4 (b) is calculated, it is applied to the output shaft 2 shown in FIG. 4 (c). Output shaft operating torque can be obtained. As shown in FIG. 4C, the output shaft operating torque applied to the output shaft 2 becomes a large driving force from the operation start time of the main lever 3, and becomes a torque curve in which the driving force decreases near the end of the operation.

  As described above, according to the energy storage device of the on-load tap switching device of the present invention, by providing the main spring with the auxiliary spring, the driving force at the initial stage of the switching switch operation (when the main lever starts to rotate) can be obtained. Can be bigger. As a result, a shift in the operating speed of the main lever is suppressed, and the main lever rotates at a constant speed as compared with the prior art, so that the operation timing of the switching control of the switching switch is stabilized.

  For example, when the switching switch is switched in the operation sequence shown in FIG. 5A (the details of the operation are the same as those in FIG. 6 described above), as shown in FIG. 5B, the main lever The vacuum valves V1 and V2 are switched and the changeover switch S is switched instantaneously from the start of the movement until it stops. That is, if the initial operation speed of the main lever is slow in the switching switch, the opening / closing operation of the vacuum valves V1, V2 may become unstable.

  On the other hand, the energy storage device of the on-load tap switching device according to the present invention can increase the driving force at the start of operation of the main lever (increase the rotation speed of the main lever). The stability of the opening / closing operation can be improved.

  Further, by providing an auxiliary spring at the tip of the main lever, the output shaft operating torque by the main spring can be reduced. As a result, the strength of each member constituting the energy storage device can be reduced, and the energy storage device can be reduced in size.

  Also, the auxiliary spring acts as a brake for the main lever after the main lever exceeds the intermediate point, so that it is provided at the operation end point of the main lever and reduces the impact force applied to the contact plate that restricts the movement of the main lever. be able to. As a result, the backing plate can be made smaller, and the energy storage device can be further downsized.

  Further, by providing the stopper, the rotation of the main lever is started not when the main spring exceeds the dead point but when the main spring and the main lever move by a certain angle. As a result, the driving force at the start of operation of the main lever can be increased. Furthermore, by providing the auxiliary lever with a protrusion for releasing the stopper, the stopper can be released at a predetermined timing. That is, the timing at which the rotation of the main lever starts can be controlled.

  The energy storage device of the on-load tap switching device of the present invention is not limited to the above-described embodiment, and can be appropriately designed and modified within a range that does not impair the operation and effect thereof. The form also belongs to the technical scope of the energy storage device of the on-load tap switching device of the present invention. For example, in the embodiment, an example in which the energy storage device of the on-load tap switching device of the present invention is applied to a vacuum valve type switching switch has been described, but the switching circuit method of the switching switch is not particularly limited. However, the energy storage device of the present invention can be applied to a known switching switch as appropriate.

DESCRIPTION OF SYMBOLS 1 ... Energy storage apparatus 2 ... Output shaft 3 ... Main lever 3a ... Locking groove 4 ... Drive part 5 ... Auxiliary spring 6 ... Stopper 7 ... Auxiliary lever 7a ... Projection part 8 ... Main spring 9 ... Drive lever 10 ... Link 11 ... Worm gear

Claims (2)

An energy storage device for a load tap switching device that switches a circuit according to rotation of an output shaft,
A main lever having one end fixed to the output shaft;
An auxiliary lever that is pivotally supported at one end by the output shaft and controls the operation of the main lever;
A main spring provided between the other end of the main lever and the other end of the auxiliary lever;
An auxiliary spring provided at the other end of the main lever and pulling the main lever to the center of the operating range of the main lever;
An energy storage device for an on-load tap switching device, comprising: a stopper that is locked in a locking groove formed at one end of the main lever, and that temporarily restricts rotation of the main lever. The load tap switching according to claim 1, wherein a protrusion is provided on a surface of the auxiliary lever facing the main lever, and the stopper is released by the protrusion according to the rotation of the auxiliary lever. Energy storage device of the device.

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