Patent Application
20190157017
This application claims benefit of European Patent Application No. 17382786.6 filed on Nov. 21, 2017, herein incorporated by reference in its entirety.
The present invention relates to a drive system for high-voltage electrical devices, such as a load break switch-disconnector or a grounding disconnector, for example, said drive system comprising a subassembly that allows motorizing the switching of at least two manually operated electrical devices, such as the switching of a load break switch-disconnector and a grounding disconnector, for example.
The electrical equipment used in utility grids may comprise electrical switching devices that carry out the connection, breaking and/or disconnecting and grounding the installation. Therefore in the event of, for example, a fault in the distribution line, an outage due to works, maintenance or optimization of the load distribution, such electrical devices can be actuated remotely to obtain the desired electric power distribution, to prevent consumers from being left without power or to assure the protection of people and electrical equipment such as transformers, for example.
These high-voltage electrical devices may consist of circuit breakers, load break switches, grounding disconnectors, etc., provided with a movable contact and a fixed contact. To perform these switching functions, a drive force produced by a drive system is transmitted to the movable contact of the high-voltage electrical device. The intervention of the drive system can be both voluntary, ordered by an operator regardless of the current value, and due to the action of a device that is sensitive to given current values which directly or indirectly order the circuit to be opened.
In electrical equipment in which a load break switch-disconnector and a grounding disconnector have been arranged, where the load break switch-disconnector is in charge of performing the operations for connecting and breaking/disconnecting the circuit and the grounding disconnector is in charge of connecting the circuit to the ground or disconnecting it from same, the switching of the load break switch-disconnector can typically be manual or motorized, whereas switching of the grounding disconnector is usually manual.
The fact that the switching of the grounding disconnector may not be motorized may entail several drawbacks, such as the risk that an operator may suffer an accident to the manual switching of the grounding disconnector without first resolving a fault existing in the grid or due to the performance of a false switching in the grid, for example. Likewise, though not such a serious drawback as the drawback of suffering an accident, not motorizing the switching of the grounding disconnector entails at least one operator having to go to the installation, such as when performing a line transfer, for example.
There are examples in the state of the art in which the switching of the grounding disconnector is in fact motorized, but in these cases, the switching of the load break switch-disconnector typically is not. Therefore, only examples in which the switching is motorized for just one of the electrical devices, i.e., for the load break switch-disconnector or for the grounding disconnector, have been known up until now. On the other hand, for reasons of safety both electrical devices can never be acted on at the same time, there being interlocks to prevent said joint switching.
The present invention relates to a drive system for high-voltage electrical devices, such as a load break switch-disconnector or a grounding disconnector, for example, with at least two switching positions, a first connection position and a second opening position, which can be applied in high-voltage utility grids, and comprising at least one fixed contact and one movable contact, the movable contact being attached to a drive system such as the drive system of the present invention.
The drive system comprises a main drive assembly and a subassembly coupleable to at least a first electrical device (such as a load break switch-disconnector, for example) and a second electrical device (such as a grounding disconnector, for example), allowing the drive system to transmit at least two switching positions (connection and opening) to the first electrical device or the second electrical device.
The subassembly coupleable to the first electrical device or the second electrical device therefore allows switching both electrical devices by a single drive system. To that end, said subassembly comprises coupling of at least two working positions, the first position being associated with the first electrical device and the second position being associated with the second electrical device.
The switching of the electrical devices is preferably a motorized switching operation, where the movement generator may be a hydraulic device, pneumatic device, electrical device, magnetic device, inertial device, thermal device, hybrid device, etc., such that the coupling can be operated remotely. Therefore, both the first electrical device and the second electrical device can be switched remotely, thereby preventing the risk of suffering an accident due to the manual switching of one of the two electrical devices, such as due to the manual switching of a grounding disconnector in fault conditions, for example. Likewise, due to the motorization of the switching of both electrical devices, operators do not have to go to the installation to perform jobs of this type. However, for reasons of operator safety manual switching will always take priority over motorized switching, such that manual switching can override any motorized order.
The coupling mechanism can comprise a driving element which is in turn associated with a mechanical coupler. This mechanical coupler is integrally attached to a drive shaft of a motor. In this sense, the driving element can displace said mechanical coupler in one direction or the other on said drive shaft of the motor depending on the order that is given, i.e., a connection order or opening order. The mechanical coupler can thereby be coupled to a first coupling element or a second coupling element, the first coupling element being associated with the first electrical device and the second coupling element being associated with the second electrical device.
Therefore, the coupling mechanisms in their first position couple the motor with the first coupling element (which may consist of a gear, chain, etc.), such that the drive system can transmit at least two switching positions (connection and opening) in a motorized manner to the first electrical device, such as a load break switch-disconnector, for example. On the other hand, the coupling mechanisms in their second position couple the motor with the second coupling element (which may consist of a gear, chain, etc.), such that the drive system can transmit at least two switching positions (connection and opening) in a motorized manner to the second electrical device, such as a grounding disconnector, for example.
The coupling mechanisms, which may be a coil, comprise a third intermediate working position with respect the first position and the second position, wherein by this third position the coupling mechanisms decouple the motor from the first coupling element and from the second coupling element. This third position of the coupling mechanisms is reached after the switching of the electrical device has been performed, and therefore after the coupling mechanisms have been de-energized.
The subassembly comprises a shell in which all its elements are internally assembled, and said shell is attached to the main drive assembly, thereby forming a drive system configured as a single part.
The possibility of the coupling mechanisms being able to be operated manually has been contemplated, such that once the mechanical coupler has been manually displaced in a direction or the other on the drive shaft of the motor, the latter acts on the first coupling element or the second coupling element in order to carry out the switching of the first electrical device or the second electrical device.
A preferred embodiment is described below in reference to the aforementioned drawings, without this limiting or reducing the scope of protection of the present invention.
The subassembly (2) therefore allows coupling the main drive assembly (6) with the first electrical device (3) or the second electrical device (4), for the purpose of transmitting two switching positions (connection-opening) to said electrical devices (3, 4). To that end, the subassembly (2) comprises coupling mechanism (5), such as a coil, for example, for linear displacement of three working positions (A, B, C), wherein the first position (A) is associated with the first electrical device (3) and the second position (B) is associated with the second electrical device (4). The third position (C) is located in an intermediate position between the first position (A) and the second position (B), this third position (C) being a neutral position with respect to the other two positions (A, B), as shown in
As can be seen in
As shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 17382786.6 | Nov 2017 | EP | regional |
