摘要:
A switch, preferably for switching medium voltages, includes a structure which creates a gas-blast to quench an arc drawn between two separating contact pieces of the switch. The gas-blast is created solely by the quenching gas which is heated by the arc, without auxiliary pressure creating mechanisms. The gas blast is sufficiently powerful to cut off high and low currents without use of pressure-controlling valves. The result is realized via a flow-off pipe located between a space where the arc develops and a gas exhaust space. One end of the flow-off pipe opens into the exhaust space. The size of the flow-off pipe is determined in part by the speed of propagation of a pressure wave which is formed in the arc space during the heating phase of the arc and the length thereof is deliberately selected such that the pressure gradient between the heated quenching gas and the arc space is maximized.
摘要:
A high-voltage circuit breaker includes two arcing contacts, which are capable of moving relative to one another along an axis, an insulating nozzle, a heating volume for accommodating quenching gas, a heating channel, and an overpressure valve. The pressure of the quenching gas is based on the energy of a switching arc, which is formed when the breaker opens and generates arcing gas, and the heating channel opens out, with axial alignment, into the heating volume. The heating channel connects an arc zone, and the overpressure valve limits the pressure of the quenching gas by opening a relief duct, which opens out into an expansion space. In high-current switching, the pressure of the arcing gases in the arc zone is limited, and the quality of the quenching gas stored in the heating volume is improved, due to the relief duct having an outflow section extending in the radial direction.
摘要:
The electrical insulator has an insulator body 3 which is fitted between an electrical conductor 1 and a grounded holder 2. The surface of the insulator is at least partially formed by a protective body 6. The material of the protective body has a low dielectric constant in comparison to that of the material of the insulator body 3. The protective body 6 prevents an electrically conductive particle 12 from coming to rest directly on the surface of the insulator body 3, in particular in the region of the triple points T, or causing a considerable increase in the field due to immediate proximity to the insulator body 3. The breakdown voltage of a gas-insulated system which contains such insulators provided with a protective body is increased. Gas-insulated systems can thus be made more compactly and more cheaply, and their life can be extended.
摘要:
In a fuse chamber (8) there is arranged as a quenching gas source a burn-off element (11), which concentrically surrounds an arc chamber (10) and is separated from it by a fuse element (9), which consists of metal foil, preferably silver foil, and the outer side of which is adjoined by the burn-off element (11). The latter consists of an igniting material (12), arranged in the form of a ring running around centrally, and a gas-evolving material (13). Both materials consist, for example, of guanidine or guanidine derivatives as the combustible material and an oxidant, the proportion of which in the igniting material (12) is hyperstoichiometric. The arc chamber (10) is bounded at opposite ends by nozzles (7a,b), which connect it to exhaust volumes (4a,b). When there is an overcurrent, the fuse element (9) heats up to the igniting temperature of the igniting material (12) and is torn open centrally. The arc forming is axially blown by the quenching gas, which forms during the burning-off of the burn-off element (11), and quenched. The fuse element (9) may centrally have a triggering zone, where it is more easily interruptible, in particular meltable. The quenching gas source may also comprise compressed-gas tanks or cold-gas generators.
摘要:
Current and voltage values (uk, ik) are measured for protection of an electrical power line (1). An adaptive estimator is used to analyze all the values within a measurement window, and to convert them to impedance values (Z). The line (1) is switched off if the impedance values (Z) assume unacceptable values. In order to shorten the reaction time, a warning signal (W) is produced if powerful radio-frequency signals are detected on the line (1). When the warning signal (W) occurs, the respective measurement window is located such that its start matches the time of the warning signal (W), and/or the respective measurement window is shortened.
摘要:
This hybrid circuit breaker has at least two series-connected arcing chambers which are operated by a common drive or by separate drives and are filled with different arc extinguishing media. The arc extinguishing and insulating medium in the first arcing chamber surrounds the second arcing chamber in an insulating manner. The aim is to provide a hybrid circuit breaker which can be produced economically and which has high availability. This is achieved, inter alia, wherein means are provided which always ensure that the movement of the first arcing chamber leads the movement of the second arcing chamber during a disconnection process, and that the movement of the second arcing chamber always leads the movement of the first arcing chamber during a connection process.
摘要:
A device for switching electric current includes a compressed gas switch, at least one vacuum switch, and two terminals. A first consumable contact of the compressed gas switch is electrically connected to a first of the two terminals and a movable electrode of the vacuum switch is connected to a second of the two terminals to form a quenching circuit. The two electrodes of the vacuum switch can be separated without the use of the drive and a contact pressure is applied to them which prevents the electrodes from breaking below a threshold value of the current to be switched off. On switch-off, the current to be interrupted is switched over from a rated current circuit containing two rated current contacts of the compressed gas switch to the parallel quenching circuit. The vacuum switch now in the quenching circuit breaks only if the current to be switched off exceeds the aforementioned threshold. As the vacuum switch does not conduct the rated current and, unlike the compressed gas switch, is involved only in a few break operations, it can be of substantially lighter construction than a vacuum switch carrying the rated current and is actuated in every switching operation.
摘要:
An arrangement for semiconductor power components in an installation, in which at least one semiconductor power component is placed between contact pieces and is enclosed in a housing exhibiting an insulator and connecting pieces. The arrangement includes current conductors which promote safety and prevent explosion by absorbing electric arcs formed in the installation. The current conductors are placed laterally adjacent to the contact pieces and annularly surrounding the latter, separated from the interior wall of the insulator by narrow gaps. Additional embodiments of the present invention employ reinforcing elements around the housing, and explosion guards around the housing, thereby further enhancing installation safety.
摘要:
An electrical power switch operating with a pressurized gas for actuating the switch contacts and also providing a quenching action in which the arc is lengthened and extinguished includes a container in which the pressurized gas is stored, the outlet from this container being located adjacent the junction area between a plurality of contact fingers in fixed position and a movable contact member that also includes a valve member for closing off the gas outlet from the container when the switch contacts are closed. When the movable contact is released for initiating an opening operation of the contacts, the pressure of the gas stored in the container forces the valve open thus releasing the gas for blasting the arc drawn between the contacts. The gas enters an annular chamber surrounding the junction line of the contacts which includes two half-turn helical travel rails of different radius and opposite winding sense to which the feet of the arc are transferred from the contacts and travel downward and into a group of circumferentially spaced nozzles in which the arc is further lengthened.
摘要:
An exemplary high voltage circuit breaker includes an interruption chamber that is filled with an extinguishing agent. The interruption chamber having at least two separable arcing contact pieces that are coaxially arranged and an arcing zone in which an electric arc is producible during an interruption process. The interruption chamber includes at least two inlets and at least one outlet located in between the two inlets. The inlets and the at least one outlet are connected with the arcing zone such that the electric arc is extinguishable in at least three arc interruption zones by means of extinguishing flows streaming out of the at least two inlets into the arcing zone upon pressurization and introduction of a portion of the extinguishing agent in the arcing zone, and leading an amount of the extinguishing flows through the outlet out of the arcing zone.