352 results about "Surge arrester" patented technology

The application describes an electrical terminal comprising a pair of longitudinally disposed contact members, each having a pair of insulation displacement connectors connectors, one at either end thereof, thereby to link two wire pairs, wherein. each contact member comprises a contact arm each extending in a defined direction, the contact arms leading to a pair of arrestor contacts spaced so as to accept a surge arrestor. The defined direction is preferably substantially transverse to the contact members. This enables the surge arrestor to be placed to one side of the electrical terminal, avoiding interference with ingoing and outgoing wires and avoiding inhibiting access to test points. The contact members are preferably parallel within the electrical terminal. The arrestor contacts are preferably spring contacts, thereby to enable replacement of the arrestor. The contact arms more preferably end at the spring contacts. In a particularly preferred embodiment, the contact arms are non-contiguous with the contact members but are joined thereto. This join can be by way of a lug extending from the edge of one of the two members and engaging within a slot of the other. This provides a particularly simple but effective electrical contact. The lug is preferably on the contact members, thereby placing the slot on the contact arms. This also avoids the need to bend a single-piece blank, thereby risking damage to or distribution of the IDC connector. The terminal will ideally be enclosed within a plastic housing, and this will preferably comprise a recess for receiving the surge arrestor, the arrestor contacts extending into the recess.

The magnetic circuit of a generator in a wind power plant is arranged to directly supply a high supply voltage of 2-50 kV, preferably higher than 10 kV. The generator is provided with solid insulation and its winding includes a cable (6) comprising one or more current-carrying conductors (31) with a number of strands (36) surrounded by at least one outer and one inner semiconducting layer (34, 32) and intermediate insulating layers (33). The outer semiconducting layer (34) is at earth potential. The stator winding may be produced with full or fractional slot winding, the phases of the winding being Y-connected. The Y-point may be insulated and protected from over-voltage by means of surge arrestors, or else the Y-point may be earthed via a suppression filter. The invention also relates to a wind power plant, a generator included in the plant and a variable speed system for such a plant.

A circuit breaker comprising a first dc line electrically connectable to first incoming and first outgoing dc lines, wherein the first dc line comprises a first fault-interrupting switch contact system and a first switching aid network. The first switching aid network comprises first and second rectifier strings, wherein each rectifier string comprises one or more series connected reverse blocking power electronic devices that define a first H-bridge rectifier. The first switching aid network further comprises a snubber string, the snubber string comprising at least one series connected power electronic devices capable of being turned on by gate control and a capacitor. The first switching aid network further comprises a pre-charge string comprising at least one series connected power electronic devices capable of being turned on by gate control and a resistor, and a surge arrester connected between the first and second dc output terminals of the first H-bridge rectifier.

An electrical surge arrester is manufactured by securing a stack of metal oxide varistor blocks between end terminations by passing a rod through through-holes in the varistor blocks and securing the ends of the rod to the end terminations. The through-holes are larger than the rod cross-section and a silicone rubber material is injected into the void which otherwise would exist between the rod and the interior surfaces of the through-holes in the varistor blocks. The silicone rubber material is also moulded around the exterior of the stacked varistor blocks and forms a shedded external housing for the arrester. The silicone rubber coatings on the varistor block internal and external surfaces effects a passivation function and means that the passivation coatings normally provided on the surfaces of varistor blocks by their manufacturers at significant cost can be omitted.

The present invention relates to an apparatus for sensing and measuring the HV surge arrester current. It comprises two toroidal current transformers arranged coaxially with respect to the earth wire of the surge arrester, means for sensing the current signals emitted by the said transformers and for converting the said current signals in digital signals, and means for transmitting the said digital signals to an information network and analog state signals by relay activation. The two toroidal current instrument transformers are associated, respectively, one to means for sensing the normal leakage current, and the other to means for sensing the impulsive current, the latter comprising a circuit (TRIGGER) discriminating between "switching" and "lightning" signals, in which the basis for discrimination is a signal duration threshold, of about 35 mus.

A power factor correction device (1) having one or more capacitors (10) in which the capacitance can be varied depending on the amount of power factor correction that is needed for a given application. Disconnect blocks (16) having internal bridging bars (19) are used to activate and deactivate fixed-value capacitors (13) and/or variable capacitance capacitors (12) within the device. The device may use variable capacitance capacitors either alone or in combination with fixed-value capacitors depending on the size of an electrical circuit. In addition to reducing electrical usage by correcting power factor, surge protection is promoted through the use of surge arresters (18).

A system for transient over voltage protection of a three-phase transformer. Two surge arresters are series connected across each winding of the transformer and the center point connection of the two surge arresters is electrically connected to a middle location of the winding. Three additional surge arresters are electrically connected from each phase to ground in the case of either a delta or Y connected transformer; and/or connected from a neutral point to ground in the case of a Y connected transformer. The system allows for all of the surge arresters to be packaged as an integrated surge arrester system to minimize induced transient over voltages and high stresses on the transformer winding due to internal resonances.

A breaker failure detection device for a direct current (DC) circuit breaker (200) is provided. The circuit breaker comprises a circuit breaking element (204) and a non-linear resistor, e.g., a surge arrester (205), connected in parallel. The breaker failure detection device comprises a current sensor (212, 213, 214, 215), for measuring a current commutating from the circuit breaking element (204), and a breaker failure detection unit (211). The breaker failure detection unit (211) is arranged for comparing the measured current to desired values and deciding that an internal commutation process of the circuit breaker (200) does not proceed as desired if the measured current deviates from the desired values. The present invention makes use of an understanding that an improved detection of breaker failures may be achieved by monitoring the internal commutation process of the circuit breaker. Further, a method of breaker failure detection is provided.

A monitoring system in accordance with one embodiment comprising a plurality of surge arrestors; a plurality of probes coupled, each one of the plurality of probes coupled to one of the plurality of surge arrestors; the plurality of probes comprising at least one current probe and at least one voltage probe; a switching matrix coupled to the plurality of probes; and an electronic measuring device coupled to the switch, the electronic measuring device for measuring signals from the plurality of probes, the signals corresponding to a status of each of the plurality the surge arrestors.

The invention relates to an overvoltage protection device, comprising at least one surge arrester and one switchgear assembly, which is connected in series to the surge arrester and which can be triggered thermally, wherein the aforementioned components form a structural unit, and the thermal tripping means is arranged in the area of the expected heating up of the surge arrester when overloaded. According to the invention, the thermal tripping unit is configured as a stop element through which operating current or surge current does not flow. In the event of thermal overload, the stop element opens a releasing device of the switchgear assembly, wherein said switchgear assembly has an increased self-extinguishing capacity.

A device for controlling a power flow in an electric power transmission system. A control circuit includes a first inductor and a semiconducting switching element connected in parallel with the first inductor. The control circuit also includes a first bypass path including a surge arrester. A second bypass path is connected in parallel with the control circuit. The second bypass path includes a closing switch. The device also includes a resistor.

In one embodiment, a device for coupling communications signals onto a medium-voltage power line includes a first connector, a second connector and one or more components. The first connector is adapted to couple to a low-voltage communications line. The second connector is adapted to couple to a surge arrester. The one or more components are operable to substantially match the impedances between the surge arrester and the low-voltage communications line.