Drive system for actuating an on-load tap changer, and transformer device having a drive system

Abstract

The invention relates to a drive system (2) for actuating an on-load tap changer (20), comprising - a drive module (30) and - a control module (40), wherein - the control module (40) actuates the on-load tap changer (20) via the drive module (30), and - the drive module (30) is directly mechanically connected to the on-load tap changer (20) and the control module (40) is spatially separated from the drive module (30).

Description

[0001] DRIVE SYSTEM FOR ACTUATING AN ON-LOAD TAP-CHANGER AND TRANSFORMER DEVICE WITH A DRIVE SYSTEM

[0002] The invention relates to a drive system for actuating an on-load tap-changer and a transformer device comprising a transformer, an on-load tap-changer and a drive system.

[0003] Tap changers, especially on-load tap changers, are used for uninterrupted switching between the winding taps of a transformer. Common on-load tap changers, for example, consist of a selector for powerless pre-selection of the respective winding tap to which switching is to take place, and a load transfer switch for the actual load transfer from the previous winding tap to the new, pre-selected winding tap.

[0004] So-called reactor tap changers, which are particularly common in North America, have a switching reactance that enables slow, continuous switching. On-load tap changers based on the resistance-fast switching principle typically consist of a selector for powerless selection of the respective winding tap of the tapped transformer to which switching is to take place, and a load transfer switch for the actual switching from the previous to the new, preselected winding tap.

[0005] To perform the switching operation or operate the corresponding components, such known on-load tap-changers feature a control cabinet with an integrated motor drive, which is usually located on the outside of the transformer housing. Inside the control cabinet, in addition to the motor, various components, such as controllers, power supplies, etc., are located. The energy required to operate the on-load tap-changer is provided by a corresponding power supply. This type of drive is large and not very flexible, thus complicating service and maintenance work.

[0006] It is therefore an object of the present invention to provide a drive system which is compact and safe and can be easily assembled.

[0007] This object is solved by the subject matter of independent claim 1. Further embodiments are the subject matter of the dependent claims.

[0008] A further object of the present invention is to provide a transformer device that is easy to maintain. This object is achieved by the subject matter of independent claim 8. Further embodiments are the subject matter of the dependent claims.

[0009] To achieve this, the invention proposes a drive system for actuating an on-load tap-changer, comprising a control module, a drive module, wherein the control module actuates the on-load tap-changer via the drive module, the drive module is mechanically connected directly to the on-load tap-changer, and the control module is arranged spatially separated from the drive module.

[0010] The drive system consists of a drive module and a control module and operates an on-load tap-changer. The drive module is located directly below the on-load tap-changer on its base, i.e., its housing. "Directly" means that the drive module is bolted to the base of the on-load tap-changer or connected to it by a weld or a similar fastening method.

[0011] The control module is connected to the drive module via a first cable, but is spatially separated from the drive module. Spatially separated means that both the control module and the drive module are each located in their own housing, and these respective housings are arranged at a distance from one another. The control module has a control cabinet, and the drive module has, for example, a metal housing. While the drive module is located directly below the on-load tap-changer and is directly connected to it, the control module can be arranged anywhere around or on the transformer. The control module is preferably arranged so that it is easily accessible for service and maintenance personnel.

[0012] The spatial separation of the control module from the drive module offers several advantages.

[0013] First, the drive module and the control module can be assembled and disassembled separately. This also simplifies maintenance, as service / maintenance personnel can access the respective module much more easily and replace or service the defective module accordingly. The drive module can be designed in any desired manner and preferably includes a motor with a motor shaft, a drive shaft, at least one microswitch, a hand crank, and a step position indicator.

[0014] All elements are installed in a housing. The motor shaft is connected to the drive shaft, for example, via a gear. The hand crank serves as a manual drive and is preferably attached directly to the motor and designed or arranged to be accessible from the outside. The tap position indicator is preferably readable from the outside. The at least one microswitch of the drive module is used to control the speed and position of the motor during a load changeover. The at least one microswitch or further microswitches also determine the start and end of a changeover of the on-load tap changer. The motor can preferably be designed as an asynchronous machine with Steinmetz circuit, as a stepper motor, as a servo motor, or as a DC motor and can be operated in both single-phase and multi-phase mode.

[0015] The control module can be designed in any way and preferably comprise a control unit and / or a motor module.

[0016] The control unit is configured to receive switching commands to operate the on-load tap-changer. The switching commands can be transmitted to the control unit from external sources. Additionally, the control unit can include a voltage regulator that can independently generate switching commands based on measured voltages and currents. These external sources can be, for example, a remote control center that accesses the control module via a data connection or a mobile data connection that allows a service technician to access the control module.

[0017] The control module can be designed in any way and preferably includes a display.

[0018] The control module is preferably designed as a control cabinet, with the display integrated into the control cabinet. The display is configured to provide or output information to maintenance or service personnel about the operating status of the transformer, the on-load tap-changer, and the drive system with the control module and drive module. For example, the display can show operating data for the respective equipment and transmit information about potential malfunctions. The display can also be configured as a touchscreen and serve as a control surface for entering instructions for the various equipment and the drive system.

[0019] The control module can be configured in any way and preferably includes a vacuum interrupter monitoring system. The vacuum interrupter monitoring system is designed and configured to monitor vacuum interrupters in the diverter switch of the on-load tap-changer. For this purpose, current transformers arranged in the power supply lines of the vacuum interrupter monitor the function of the vacuum interrupter and, in the event of a fault, generate a signal that blocks the control module, the motor, and thus the on-load tap-changer, thus preventing faulty, non-load-free switching of the selector. The (fault) signals regarding the status of the vacuum interrupters in the on-load tap-changer are transmitted to the control module and the vacuum interrupter monitoring system via lines and a second cable.The vacuum interrupter monitoring system is designed and constructed to output the status of the vacuum interrupters and, in the event of a fault, to issue an alarm, for example on the display of the control module.

[0020] The drive module and the control module are preferably connected to each other via a first cable. The first cable serves both as a power supply and as a signal transmission device. For this purpose, the first cable contains several lines or wires.

[0021] Furthermore, the on-load tap-changer is preferably connected to the vacuum interrupter monitoring system of the control module via a second cable. For this purpose, the second cable can also contain several lines or wires. The cables can be, for example, fiber optic cables and / or copper cables.

[0022] According to a second aspect, a transformer device is proposed, comprising a transformer; an on-load tap changer and a drive system for actuating the on-load tap changer.

[0023] The on-load tap-changer can be positioned anywhere on any of the four side walls of the transformer. The transformer windings are routed into the on-load tap-changer via cables via a so-called "barrier board," which forms the common plane between the transformer side wall and the on-load tap-changer wall. The on-load tap-changer is mechanically connected to the drive module of the drive system via the drive shaft. The drive shaft extends through the on-load tap-changer to the drive module, which is located directly below the on-load tap-changer on the on-load tap-changer base.

[0024] The transformer is preferably designed as a tap-changer. The on-load tap-changer can be configured in any desired manner and can preferably comprise a diverter switch and a selector and / or be designed as a reactor switch.

[0025] They show:

[0026] Figure 1 shows a transformer device with an on-load tap changer and a

[0027] drive system;

[0028] Figure 2 shows a more detailed representation of the drive system according to the invention.

[0029] Figure 1 shows a transformer device 1 comprising a transformer 10, an on-load tap-changer 20, and a drive system 2. The on-load tap-changer 20 and the drive system 2 form an on-load tap-changer device 19. The transformer 10 has an active part with a core and windings 14 with winding taps. The on-load tap-changer 20, for uninterrupted load switching between the different winding taps of the transformer 10, has a load transfer switch and a selector. The drive system 2 comprises a drive module 30 and a control module 40.

[0030] The on-load tap-changer 20 is designed according to the reactor switching principle. Unlike on-load tap-changers based on the resistance-type switching system, on-load tap-changers 20 based on the reactor switching principle use reactors, which can also be referred to as reactors. Unlike resistors, the reactors do not heat up disruptively when circulating current flows, which means that the switching process does not have to be as fast as possible. For this reason, a spring energy storage device in the drive, which would quickly perform a switchover, is not required.

[0031] Both the transformer 10 with its housing and the on-load tap-changer 20 with its on-load tap-changer housing are essentially cuboid-shaped. The transformer 10 has a lower side, which is designed as a transformer base 12. This lower side, i.e. the transformer base 12, is connected to the subsurface or ground in an operating state. The transformer 10 therefore stands on the subsurface. The transformer 10 also has several side walls 11.1, 11.2, preferably four, and a transformer cover 13. The transformer cover 13 is arranged opposite the transformer base 12 and thus opposite the lower side. The side walls 11.1, 11.2, the transformer cover 13 and the transformer base 12 are connected to one another and form the housing. The on-load tap-changer 20 also has a lower side, which is designed as an on-load tap-changer base 22.In addition, the on-load tap-changer 20 has an on-load tap-changer cover 23, which is parallel to the on-load tap-changer base 22, as well as four on-load tap-changer walls 21. These parts form the on-load tap-changer housing of the on-load tap-changer 20.

[0032] The on-load tap-changer base 22 is aligned essentially parallel to the transformer base 12, and the on-load tap-changer cover 23 is aligned essentially parallel to the transformer cover 13. In the assembled state, the on-load tap-changer 20 is attached to one of the side walls, here the first side wall 11.1 of the transformer 10. The first side wall 11.1 of the transformer 10 and one of the on-load tap-changer walls 21 form a common plane 25. The on-load tap-changer 20 is mounted on an upper side of the transformer 10, i.e., closer to the transformer cover 13 than to the transformer base 12. The on-load tap-changer base 22 therefore does not form a common plane with the ground, but is located approximately 1.5 to 3 meters above the ground.

[0033] The on-load tap-changer 20 is connected to the windings 14 inside the transformer 10 via lines 15. The lines 15 are led from the transformer 10 into the on-load tap-changer 20 at the common plane 25 where the on-load tap-changer wall 21 and the first transformer side wall 11.1 form an interface.

[0034] Located below the on-load tap-changer 20 is its drive module 30. The drive module 30 is part of the drive system 2 and is designed and configured to drive or operate the on-load tap-changer 20 with its diverter switch and selector. For this purpose, the drive module 30 is attached below the on-load tap-changer 20 to the on-load tap-changer base 22 and is connected to the diverter switch and the selector of the on-load tap-changer 20 via a drive shaft 24. The on-load tap-changer 20 is operated via the drive module 30 via the drive shaft 24. The precise structure of the drive module 30 and its mode of operation are described in more detail in Figure 2.

[0035] The control module 40 is connected to the drive module 30 via a cable 50. The control module 40 is also part of the drive system 2.

[0036] The control module 40 can be configured, for example, as a control cabinet and mounted, for example, on a second side wall 11.2 of the transformer 10. The control module 40 is located on the lower side of the transformer 10, i.e., closer to its base part 12. The control module 40 is positioned on the transformer 10 so that it is easily accessible for maintenance or service personnel. The further structure of the control module 40 and its functionality are described further in Figure 2.

[0037] Figure 2 shows a schematic representation of the drive system 2. The drive system 2 comprises the drive module 30 and the control module 40. The drive module 30 is located directly below the on-load tap-changer 20 on the on-load tap-changer base 22, i.e., on the on-load tap-changer housing, and is connected to the on-load tap-changer 20, among other things, via a drive shaft 24. The control module 40 is arranged at a distance and spatially separated from the drive module 30 and, in this embodiment, is arranged, for example, on a wall of the transformer 10. The control module 40 can, however, be arranged anywhere around the transformer 10; however, it is always detached, i.e., spatially separated from the drive module.

[0038] 30 arranged.

[0039] The drive module 30 comprises a motor 36 with a motor shaft 26, a step position indicator 31, a hand crank 32 and at least one microswitch 37. The step position indicator

[0040] 31 is designed as a mechanical tap position indicator 31. The at least one microswitch 37 of the drive module 30 is used for communication with the control unit 40 and for controlling the motor 36 during a switchover of the on-load tap-changer 20, i.e., a switchover from a current winding tap n to an adjacent winding tap n+1. A further microswitch 37 also determines the end and start of a switchover. The motor shaft 26 is preferably mechanically coupled to a drive shaft 24 via a gear mechanism. The motor 36 thus drives the on-load tap-changer 20 via the drive shaft 24 and the motor shaft 26. Several cams (not shown here) on the drive shaft 24 interact with the at least one microswitch 37; in particular, the cams actuate the at least one microswitch 37.In this embodiment, the motor 36 is designed as an asynchronous machine with a Steinmetz circuit, which can be operated in both single and multi-phase mode.

[0041] The tap position indicator 31 is also connected to the drive shaft 24 and displays the current tap position of the on-load tap-changer 20. This enables maintenance / service personnel to read the position, in particular the tap position, of the on-load tap-changer 20 directly on the drive module 30.

[0042] Furthermore, a hand crank 32 is installed in the drive module 30, which is mechanically connected to the motor 36 via the motor shaft 26. The hand crank 32 serves to manually operate the motor 36 and thus the on-load tap-changer 20, for example, when the drive module 30 is disconnected from the power supply. Maintenance / service personnel can use the hand crank 32 to manually change the tap position of the on-load tap-changer 20.

[0043] In this embodiment, the control module 40 is designed as a control cabinet and includes a display 44, a motor module 42, and a control unit 43. The control unit 43 is designed and configured to receive switching commands in order to actuate the on-load tap-changer 20 using the drive module 30. The switching commands can be transmitted to the control unit 43 from external sources. Furthermore, the control unit 43 can include a voltage regulator that can independently generate switching commands based on measured voltages and currents.

[0044] The control module 40 is connected to the drive module 30, and in particular to the motor module 42 and the control unit 43, via a first cable 50. The motor module 42 and the control unit 43 receive various signals from the microswitches 37 of the drive module 30 via the cable 50. The control unit generates the step position from these signals. This step position can then be output via the display 44, for example, to maintenance / service personnel, since they are connected to the control unit 43.

[0045] The motor module 42 preferably consists of several contactors. The contactors are designed and configured to switch the power to the motor 36 on and off, thus operating the motor 36.

[0046] The motor module 42 and the control unit 43 are designed and configured to actuate the motor 36 and thus the on-load tap-changer 20 via the at least one microswitch 37 based on the switching commands of the control unit 43 and to monitor this actuation. The first cable 50 also serves to supply power to the motor 36.

[0047] During the actuation of the motor 36, i.e., the switching of the on-load tap-changer 20, the motor position and / or the time are monitored in the motor module 42 via at least one microswitch 37. See the previous paragraph.

[0048] Furthermore, the control module 40 is designed and configured to monitor the vacuum interrupters in the diverter switch of the on-load tap-changer 20. For this purpose, the control module 40 has a vacuum interrupter monitoring unit (VIM) 45. Current transformers arranged in the power supply lines of the vacuum interrupter monitor the function of the vacuum interrupter and, in the event of a fault, generate a signal that blocks the control module 40 of the on-load tap-changer 20, thus preventing faulty, non-load-free switching of the selector. Via fiber optic cables inside the on-load tap-changer 20 and a second copper cable 65, the (fault) signals regarding the status of the vacuum interrupters are then transmitted from the on-load tap-changer 20 to the control module 40 and its VIM 45. The VIM 45 is designed as a microcontroller and is connected to the motor module 42 and the control unit 43.The VIM 45 is designed and constructed to output the status of the vacuum interrupters and to issue an alarm in the event of a fault.

[0049] In addition, if a fault occurs, the control module 40 is capable of stopping the drive module 30 of the on-load tap-changer 20 and returning it to its initial position, as well as triggering a motor protection switch of the drive module 30. To do this, the VIM 45 sends control commands to the motor module 42, which then stops the motor 36 and thus the on-load tap-changer 20. The VIM 45 can either be part of the motor module 42 or be arranged separately in the control module 40.

[0050] REFERENCE SYMBOL

[0051] 1 transformer device

[0052] 2 drive system

[0053] 10 Transformer

[0054] 11.1 first transformer side panel

[0055] 11.2 second transformer side wall

[0056] 12 Transformer base

[0057] 13 Transformer cover

[0058] 14 windings

[0059] 15 lines

[0060] 19 On-load tap-changer device

[0061] 20 on-load tap-changers

[0062] 21 On-load tap-changer wall

[0063] 22 On-load tap-changer base

[0064] 23 On-load tap-changer cover

[0065] 24 Drive shaft

[0066] 25 common level

[0067] 26 Motor shaft

[0068] 30 drive module

[0069] 31 mechanical tap position indicator

[0070] 32 hand crank

[0071] 36 Engine

[0072] 37 microswitches

[0073] 40 Control module

[0074] 42 Motor module

[0075] 43 Control unit

[0076] 44 Display vacuum interrupter monitoring first cable second cable

Claims

CLAIMS 1. Drive system (2) for actuating an on-load tap-changer (20), comprising a control module (40), a drive module (30), wherein the control module (40) actuates the on-load tap-changer (20) via the drive module (30), the drive module (30) is mechanically connected directly to the on-load tap-changer (20) and the control module (40) is arranged spatially separated from the drive module (30).

2. Drive system (2) according to claim 1, wherein the drive module (30) comprises a motor (36) with a motor shaft (26), a drive shaft (24), at least one microswitch (37), a hand crank (32) and a step position indicator (31).

3. Drive system (2) according to claim 1 to 2, wherein the control module (40) comprises a control unit (43) and / or a motor module (42).

4. Drive system (2) according to one of claims 1 to 3, wherein the control module (40) comprises a display (44).

5. Drive system (2) according to one of claims 1 to 4, wherein the control module (40) comprises a vacuum interrupter monitor (45).

6. Drive system (2) according to one of claims 1 to 5, wherein the drive module (30) and the control module (40) are connected to one another via a first cable (50); the first cable (50) serves both for power supply and signal transmission.

7. Drive system (2) according to claim 5, wherein a second cable (65) connects the on-load tap changer (20) to the Vacuum interrupter monitoring (45) of the control module (40).

8. Transformer device (1) comprising a transformer (10); - an on-load tap changer (20) and a drive system (2) for actuating the on-load tap changer (20) according to claims 1 to 7.

9. Transformer device (1) according to claim 8, wherein the transformer (10) is designed as a tap-changer; - the on-load tap-changer (20) comprises a load diverter switch and a selector; the on-load tap-changer is designed as a reactor switch.

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