On-load tap changer device

Abstract

The present invention relates to an on-load tap changer device, which allows the automatic regulation of voltage in the secondary winding (28) of high-voltage electrical equipment (26, 65) by selecting the number of turns of the primary winding (27) by means of an on-load tap changer device (1, 40), having reduced volume and weight, obtaining the highest possible number of transformation ratios without changing the constructive arrangement of the high-voltage electrical equipment (26, 65).

Claims

1. Three-phase on-load tap changer device comprising: at least one switching means per phase, at least one tap per phase, one selecting means per phase for selecting said at least one tap, provided with at least one electrical contact, one current-limiting element per phase, a first plate of insulating material, at least one protection element per phase, a second plate also of insulating material, and, an actuation element mounted between both plates, said actuation element being mechanically linked, as a single part, directly and simultaneously with the switching means and with the selecting means wherein the at least one switching means installed on the second plate and the taps installed on the first plate, the taps, the switching means and the selecting means thereby being mounted between both plates.

2. Three-phase tap changer device according to claim 1, wherein the actuation element comprises a rotational movement.

3. Three-phase tap changer device according to claim 1, wherein the actuation of the switching means and the actuation of the selecting means are intrinsically coordinated, such that the changeover between taps is performed with at least one switching means open.

4. Three-phase tap changer device according to claim 1, characterized in that the protection element comprises at least one varistor and the current-limiting element comprises a resistor or a reactor.

5. Three-phase tap changer device according to claim 1, further comprising an inspection window means which allows viewing the position of the tap changer device.

6. Three-phase tap changer device according to claim 1, wherein the at least one protection element is mounted between the first plate and the second plate.

7. Three-phase tap changer device according to claim 6, wherein the first plate is attached to the second plate by at least one clamping means comprising a screw and a spacer sleeve.

8. High-voltage electrical equipment, comprising: the three-phase on-load tap changer device according to claim 1, and a primary winding provided with at least one connection point associated with at least one tap, wherein the number of turns in the primary winding is variable, such that automatically regulating voltage in the secondary winding of the electrical equipment is allowed.

9. High-voltage electrical equipment according to claim 8, wherein the three-phase tap changer device can be housed inside the electrical equipment horizontally, below the upper cover of the electrical equipment, or vertically, on one side of said electrical equipment.

10. High-voltage electrical equipment according to claim 9, wherein the three-phase tap changer device comprises a startup position in coordination with the sensor system of the high-voltage electrical equipment, and a prior check of the temperature of the dielectric fluid is performed to verify that its temperature is suitable for correct operation of the three-phase on-load tap changer device.

11. Three-phase tap changer device according to claim 1, wherein the actuation element is secured to a shaft comprises an inner contour provided with protuberances, such that the rotation of the shaft makes the inner contour act on the switching means causing the opening-closing of the latter.

12. Three-phase tap changer device according to claim 11, wherein the switching means comprises a moving contact and a fixed contact, and wherein said switching means further comprises a guide element installed around same, assuring a straight and level travel of the moving contact of the switching means.

13. Three-phase tap changer device according to claim 11, wherein the actuation element comprises an outer contour provided with teeth, such that the rotation of the shaft makes the outer contour of the actuation element act on the selecting means causing the rotation of the latter.

14. Three-phase tap changer device according to claim 13, wherein the electrical contacts of the selecting means are mounted integrally to the latter, causing the connection-disconnection between these contacts and the taps, which involves the changeover between said taps.

15. Single-phase tap changer device comprising: at least one switching means, at least one tap, at least one current-limiting element (18), a first plate of insulating material, at least one protection element, a second plate also of insulating material, and an actuation element mounted between both plates, wherein said actuation element in turn comprises at least one electrical contact, said actuation element (48) is mechanically linked, as a single part, directly with the switching means and electrically linked with at least one tap through at least one electrical contact, and the at least one switching means installed on the second plate and the taps installed on the first plate, the taps, the switching means and the actuation element thereby being mounted between both plates.

16. Single-phase tap changer device according to claim 15, wherein the electrical contacts of the actuation element are mounted integrally to the latter, causing the connection-disconnection between these contacts and the taps, which involves the changeover between said taps.

17. Single-phase tap changer device according to claim 15, wherein the actuation of the switching means and the actuation of the actuation element are intrinsically coordinated, such that the changeover between taps is performed with at least one switching means open.

18. Single-phase tap changer device according to claim 15, wherein the protection element comprises at least one varistor and the current-limiting element comprises a resistor or a reactor.

19. Single-phase tap changer device according to claim 15 further comprising an inspection window means which allows viewing the position of the single-phase tap changer device.

20. Single-phase tap changer device according to claim 15, wherein the at least one protection element is mounted between the first plate and the second plate.

21. Single-phase tap changer device according to claim 20, wherein the first plate is attached to the second plate by at least one clamping means comprising a screw and a spacer sleeve.

22. High-voltage electrical equipment, comprising: a single-phase on-load tap changer device described in claim 15, and a primary winding provided with at least one connection point associated with the at least one tap, wherein the number of turns in the primary winding is variable, such that automatically regulating voltage in the secondary winding of the electrical equipment is allowed.

23. High-voltage electrical equipment according to claim 22, wherein the single-phase tap changer device can be housed inside the electrical equipment horizontally, below the upper cover of the electrical equipment, or vertically, on one side of said electrical equipment.

24. High-voltage electrical equipment according to claim 23, wherein the single-phase tap changer device comprises a startup position in coordination with the sensor system of the high-voltage electrical equipment, and a prior check of the temperature of the dielectric fluid is performed to verify that its temperature is suitable for correct operation of the single-phase on-load tap changer device.

25. Single-phase tap changer device according to claim 15, wherein the actuation element comprises a rotational movement.

26. Single-phase tap changer device according to claim 25, wherein the actuation element is secured to a shaft, and comprises an inner contour provided with protuberances, such that the rotation of the shaft makes the inner contour act on the switching means causing the opening-closing of the latter.

27. Single-phase tap changer device according to claim 26, wherein the switching means comprises a moving contact and a fixed contact, and said switching means further comprises a guide element installed around same, assuring a straight and level travel of the moving contact of the switching means.

28. Single-phase tap changer device according to claim 25, wherein the actuation element comprises an inner contour provided with protuberances, and an outer contour provided with teeth, the outer contour being mechanically linked with a transmission shaft, such that that the rotation of the transmission shaft makes the inner contour act on the switching means causing the opening-closing of the latter.

29. Single-phase tap changer device according to claim 28, wherein the switching means comprises a moving contact and a fixed contact, and wherein said switching means further comprises a guide element installed around same, assuring a straight and level travel of the moving contact of the switching means.

Description

DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a perspective view of a three-phase tap changer device according to the present invention.

(2) FIG. 2 shows a plan view of the first insulating plate of the three-phase tap changer device, where taps and protection elements are mounted.

(3) FIG. 3 shows a plan view of the second insulating plate of the three-phase tap changer device, where the switching means are mounted.

(4) FIG. 4 shows a plan view of the actuation element and the tap selecting means on the first insulating plate of the three-phase tap changer device.

(5) FIG. 5 shows an elevational view of high-voltage electrical equipment with the three-phase tap changer device installed therein.

(6) FIGS. 6a, 6b, 6c, 6d, 6e show five single-line diagrams of a three-phase or single-phase tap changer device comprising a resistor as the current-limiting element, showing the sequence of operations for performing the changeover from one tap to another.

(7) FIGS. 7a, 7b, 7c show three single-line diagrams of a three-phase or single-phase tap changer device comprising a reactor as the current-limiting element, showing the sequence of operations for performing the changeover from one tap to another.

(8) FIG. 8 shows a perspective view of a single-phase tap changer device according to the present invention.

(9) FIG. 9 shows a plan view of the first insulating plate of the single-phase tap changer device, where taps and protection elements are mounted.

(10) FIG. 10 shows a plan view of the second insulating plate of the single-phase tap changer device, where the switching means are mounted.

(11) FIG. 11 shows a plan view of the actuation element on the first insulating plate according to a first preferred embodiment of the single-phase tap changer device.

(12) FIG. 12 shows a plan view of the actuation element on the first insulating plate according to a second preferred embodiment of the single-phase tap changer device.

(13) FIG. 13 shows an elevational view of high-voltage electrical equipment with the single-phase tap changer device installed therein.

PREFERRED EMBODIMENT OF THE INVENTION

(14) Several preferred embodiments are described below in relation to the drawings mentioned above, without this limiting or reducing the scope of protection of the present invention.

(15) FIGS. 6a, 6b, 6c, 6d and 6e show single-line diagrams of the three-phase or single-phase tap changer device (1, 40) comprising a resistor as the current-limiting element (18). This resistor is installed in series with at least one switching means (2, 3, 4, 5, 6, 7), such as a vacuum interrupter, for example. The tap changer device (1, 40) further comprises at least one protection element (17) per phase, such as a varistor, for example, installed in parallel to the switching means (2, 3, 4, 5, 6, 7).

(16) FIGS. 7a, 7b and 7c show single-line diagrams of the three-phase or single-phase tap changer device (1, 40) comprising a reactor as the current-limiting element (18). This reactor (18) is installed in series with at least one switching means (2, 3, 4, 5, 6, 7), such as a vacuum interrupter, for example. The tap changer device (1, 40) further comprises at least one protection element (17) per phase, such as a varistor, for example, installed in parallel to the switching means (2, 3, 4, 5, 6, 7).

(17) The three-phase tap changer device (1) depicted in FIGS. 1-4 can be used both with resistors, and with reactors. It can be seen in FIG. 2 that the three-phase tap changer device (1) comprises at least one tap (8, 9, 10, 11, 12) per phase, mounted on a first insulating plate (20), the mentioned at least one protection element (17) being mounted on the same plate (20). An actuation element (16) and at least one selecting means (13) for selecting said at least one tap (8, 9, 10, 11, 12) are also mounted on this first plate (20), as shown in FIG. 4.

(18) In FIG. 3 it can be seen that the three-phase tap changer device (1) also comprises a second insulating plate (21) where the switching means (2, 3, 4, 5, 6, 7) are mounted. The taps (8, 9, 10, 11, 12), at least one protection element (17) and the switching means (2, 3, 4, 5, 6, 7), as well as the actuation element (16) and at least one selecting means (13), are therefore mounted between both plates (20, 21). Both plates (20, 21) are attached to one another by at least one clamping means (22) comprising a screw (23) and a spacer sleeve (24), as can be seen in FIG. 1. The arrangement of the actuation element (16) and of at least one selecting means (13) allows said actuation element (16) to act, as a single part, directly and simultaneously on the switching means (2, 3, 4, 5, 6, 7) and on at least one selecting means (13).

(19) FIG. 4 shows that the actuation element (16) is secured to a shaft (37) and further comprises an inner contour provided with protuberances (39), such that the rotation of the shaft (37) makes the inner contour act on the switching means (2, 3, 4, 5, 6, 7), causing the openingclosing of the latter. In turn, given that the actuation element (16) comprises an outer contour provided with teeth (19), shown in FIG. 4, the rotation of the shaft (37) makes said outer contour act on the selecting means (13) causing the rotation of the latter.

(20) Therefore, the actuation of the switching means (2, 3, 4, 5, 6, 7) and the actuation of the selecting means (13) are intrinsically coordinated, such that the changeover between taps (8, 9, 10, 11, 12) is performed with at least one switching means (2, 3, 4, 5, 6, 7) open. The selecting means (13) comprises at least one electrical contact (14, 15) rotating integrally with said means (13), causing the connectiondisconnection between these contacts (14, 15) and the taps (8, 9, 10, 11, 12), which involves the changeover between taps (8, 9, 10, 11, 12). As shown in FIGS. 1 and 5, the actuation element (16) can be moved or its shaft (37) can rotate due to the action of a motor (35), which can be powered by any low-voltage power source, or it can rotate manually due to the action of an operator.

(21) As shown in FIG. 5, the tap changer device (1) comprises an inspection window means (34) which allows verifying to which tap (8, 9, 10, 11, 12) the device (1) is connected. It has likewise been envisaged that the switching means (2, 3, 4, 5, 6, 7) comprising a fixed contact (36) and a moving contact (25) can comprise a guide element (38) installed around same, assuring a straight and level travel of the moving contact (25), regardless of whether the arrangement thereof in high-voltage electrical equipment is vertical or horizontal, as shown in FIG. 3.

(22) FIG. 5 shows the three-phase tap changer device (1) installed in high-voltage electrical equipment (26), such as a high-voltage/low-voltage distribution transformer, for example, where the electrical equipment (26) comprises a primary winding (27) provided with at least one connection point (29, 30, 31, 32, 33) associated with at least one tap (8, 9, 10, 11, 12), the number of turns in the primary winding (27) being variable, such that automatically regulating voltage in the secondary winding (28) of the electrical equipment (26) is allowed. The three-phase tap changer device (1) is likewise in an arrangement such that it is not affected by current-limiting elements (18), since the tap changer device (1) and the current-limiting element (18) are far enough away from one another in independent locations within the high-voltage electrical equipment (26).

(23) FIGS. 6a, 6b, 6c, 6d and 6e depict the sequence of operations carried out for performing the changeover from tap (10) to tap (11) for the case in which a resistor is used as the current-limiting element (18), for the purpose of increasing voltage in the secondary winding (28) of the high-voltage electrical equipment (26). Starting from tap (10), where switching means (2) is closed and switching means (3) is open, see FIG. 6a, electrical contact (15) is connected to tap (11), FIG. 6b, and then switching means (3) is closed, see FIG. 6c. In this position, the short-circuit current (i.sub.c) that is generated is limited by the resistor (18). In a following step, shown in FIG. 6d, the switching means (2) opens its contacts and the electrical contact (14) is then connected to tap (11). In the following operation, illustrated in FIG. 6e, the contacts of switching means (2) are closed and the contacts of switching means (3) are open to prevent Joule effect losses due to the circulation of current through the current-limiting element (18), i.e., the resistor in this case.

(24) FIGS. 7a, 7b and 7c depict the sequence of operations carried out for performing the changeover from tap (10) to tap (11) for the case in which a reactor is used as the current-limiting element (18), for the purpose of increasing voltage in the secondary winding (28) of the high-voltage electrical equipment (26). Starting from tap (10), where switching means (2, 3) are closed, see FIG. 7a, switching means (3) opens its contacts, as shown in FIG. 7b, and electrical contact (15) is then connected to tap (11). In a final step, depicted in FIG. 7c, switching means (3) closes its contacts, the short-circuit current (i.sub.c) being limited by the current-limiting element (18), i.e., the reactor in this case, which in turn allows obtaining an intermediate tap as the reactor is in a state of permanence until the following changeover of the tap, keeping losses in high-voltage electrical equipment (26) within an admissible range according to the laws in force.

(25) The difference between using resistors and using reactors as current-limiting elements (18) is that while n voltages are obtained in the first case in the secondary winding (28) of the electrical equipment (26), 2n-1 voltages are obtained in the second case in the secondary winding (28) of the electrical equipment (26).

(26) According to a second object of the invention shown in FIGS. 8 to 13, a single-phase instead of a three-phase on-load tap changer device is described below. Therefore, said single-phase tap changer device comprises: at least one switching means (2, 3); at least one tap (8, 9, 10, 11, 12); at least one protection element (17); and at least one current-limiting element (18).

(27) In addition, the single-phase tap changer device comprises a first plate (20) of insulating material and a second plate (21) also of insulating material; an actuation element (48) preferably having rotational movement, mounted between both plates (20, 21), wherein said actuation element (48) in turn comprises at least one electrical contact (49, 50); the actuation element (48) being mechanically linked, as a single part, directly with the switching means (2, 3) and electrically linked with at least one tap (8, 9, 10, 11, 12) through at least one electrical contact (49, 50).

(28) Therefore, a simpler structure of the tap changer device is obtained in this single-phase configuration in that that the three selecting means (13) seen in FIG. 4 for the three-phase case are not required, and where, in the single-phase configuration, by means of a single actuation element (48), shown in

(29) FIGS. 8, 11 and 12, it is possible to perform the functions of said selecting means (13) existing in the three-phase.

(30) Preferably, as shown in FIG. 8, the at least one protection element (17) is mounted between the first plate (20) and the second plate (21). It should be highlighted at this point that said protection element (17) comprises at least one varistor, while the current-limiting element (18) comprises a resistor or a reactor.

(31) As shown in FIG. 11, the actuation element (48) is secured to a shaft (55) and comprises an inner contour provided with protuberances (56), such that the rotation of the shaft (55) makes the inner contour act on the switching means (2, 3) causing the openingclosing of the latter.

(32) On the other hand, in the view shown in FIG. 12 it can be observed that the actuation element (48) comprises an inner contour provided with protuberances (56), and an outer contour provided with teeth (59), the outer contour being mechanically linked with a transmission shaft (60), such that that the rotation of the transmission shaft (60) makes the inner contour act on the switching means (2, 3) causing the openingclosing of the latter.

(33) Similarly to the three-phase case, the switching means (2, 3) comprises a moving contact (25) and a fixed contact (36), wherein said switching means (2, 3) further comprises a guide element (38) installed around same, shown in FIG. 10, and assuring a straight and level travel of the moving contact (25) of the switching means (2, 3).

(34) In relation to the electrical contacts (49, 50) of the actuation element (48), depicted in FIGS. 8 and 11, it has been envisaged that said contacts are mounted integrally to the actuation element (48), causing the connectiondisconnection between these electrical contacts (49, 50) and the taps (8, 9, 10, 11, 12), which involves the changeover between said taps (8, 9, 10, 11, 12).

(35) Therefore, the actuation of the switching means (2, 3) and the actuation of the actuation element (48) are intrinsically coordinated, such that the changeover between taps (8, 9, 10, 11, 12) is performed with at least one switching means (2, 3) open.

(36) In FIGS. 9 and 10 it can be seen that the taps (8, 9, 10, 11, 12) are installed on the first plate (20) of insulating material, whereas at least one switching means (2, 3) is installed on the second plate (21) also of insulating material, the taps (8, 9, 10, 11, 12), the switching means (2, 3) and the actuation element (48) thereby being mounted between both plates (20, 21).

(37) As regards the attachment between plates (20, 21), in a similar way as for the three-phase case, it has been envisaged that the first plate (20) is attached to the second plate (21) by means of at least one clamping means (22) comprising a screw (23) and a spacer sleeve (24).

(38) Likewise, the single-phase tap changer device (40) comprises an inspection window (34), shown in FIGS. 8 and 13, which allows viewing the position of the single-phase tap changer device (40).

(39) On the other hand, FIG. 13 depicts high-voltage electrical equipment (65) comprising a single-phase on-load tap changer device (40), and additionally comprising a primary winding (27) provided with at least one connection point (29, 30, 31, 32, 33) associated with at least one tap (8, 9, 10, 11, 12), the number of turns in the primary winding (27) being variable, such that automatically regulating voltage in the secondary winding (28) of the electrical equipment (65) is allowed.

(40) It should be indicated at this point that the single-phase tap changer device (40) can be housed inside the electrical equipment (65) horizontally, below the upper cover of the electrical equipment (65), or vertically, on one side of said electrical equipment (65).

(41) Also similarly to the three-phase case, the single-phase tap changer device (40) comprises a startup position in coordination with the sensor system of the high-voltage electrical equipment (65), wherein a prior check of the temperature of the dielectric fluid is performed to verify that its temperature is suitable for correct operation of the single-phase on-load tap changer device (40).

(42) Finally, the possibility of the single-phase tap changer device (40) being used in high-voltage single-phase or three-phase electrical equipment (26, 65) has been contemplated, normally using three single-phase tap changer devices (40) in the three-phase case.