A circuit breaker is an electrical safety device designed to protect an electrical circuit from damage caused by overcurrent. Its basic function is to interrupt current flow to protect equipment and to prevent the risk of fire. Unlike a fuse, which operates once and then must be replaced, a circuit breaker can be reset (either manually or automatically) to resume normal operation.
Circuit breakers are made in varying sizes, from small devices that protect low-current circuits or individual household appliances, to large switchgear designed to protect high voltage circuits feeding an entire city. The generic function of a circuit breaker, or fuse, as an automatic means of removing power from a faulty system, is often abbreviated as OCPD (Over Current Protection Device).
An early form of circuit breaker was described by Thomas Edison in an 1879 patent application, although his commercial power distribution system used fuses. Its purpose was to protect lighting circuit wiring from accidental short circuits and overloads. A modern miniature circuit breaker similar to the ones now in use was patented by Brown, Boveri & Cie in 1924. Hugo Stotz, an engineer who had sold his company to BBC, was credited as the inventor on DRP (Deutsches Reichspatent) 458392. Stotz's invention was the forerunner of the modern thermal-magnetic breaker commonly used in household load centers to this day.
Interconnection of multiple generator sources into an electrical grid required the development of circuit breakers with increasing voltage ratings and increased ability to safely interrupt the increasing short-circuit currents produced by networks. Simple air-break manual switches produced hazardous arcs when interrupting high voltages; these gave way to oil-enclosed contacts, and various forms using the directed flow of pressurized air, or pressurized oil, to cool and interrupt the arc. By 1935, the specially constructed circuit breakers used at the Boulder Dam project used eight series breaks and pressurized oil flow to interrupt faults of up to 2,500 MVA, in three cycles of the AC power frequency.
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.
Le cours a pour objectif de présenter les éléments principaux relatifs à la conception et l¿exploitation des réseaux électriques de distribution (moyenne et basse tension) tout en tenant compte de la
Ce cours décrit les composants d'un réseau électrique. Il explique le fonctionnement des réseaux électriques et leurs limites d'utilisation. Il introduit les outils de base permettant de les piloter.
A short circuit (sometimes abbreviated to short or s/c) is an electrical circuit that allows a current to travel along an unintended path with no or very low electrical impedance. This results in an excessive current flowing through the circuit. The opposite of a short circuit is an open circuit, which is an infinite resistance (or very high impedance) between two nodes. A short circuit is an abnormal connection between two nodes of an electric circuit intended to be at different voltages.
A circuit breaker is an electrical safety device designed to protect an electrical circuit from damage caused by overcurrent. Its basic function is to interrupt current flow to protect equipment and to prevent the risk of fire. Unlike a fuse, which operates once and then must be replaced, a circuit breaker can be reset (either manually or automatically) to resume normal operation. Circuit breakers are made in varying sizes, from small devices that protect low-current circuits or individual household appliances, to large switchgear designed to protect high voltage circuits feeding an entire city.
An electric arc (or arc discharge) is an electrical breakdown of a gas that produces a prolonged electrical discharge. The current through a normally nonconductive medium such as air produces a plasma, which may produce visible light. An arc discharge is initiated either by thermionic emission or by field emission. After initiation, the arc relies on thermionic emission of electrons from the electrodes supporting the arc. An arc discharge is characterized by a lower voltage than a glow discharge.
This research work deals with the design of linear CMOS RF power amplifiers. Two important aspects are treated: efficiency enhancement and frequency-tunable capability. For this purpose, two different
This paper presents a modeling approach to simulate the impact of total ionizing dose (TID) degradation on low-power analog and mixed-signal circuits. The modeling approach has been performed on 180-n
For the simulation of electrical power systems (adjustable speed drives, wind farms, complete grids, etc.) the Kirchhoff's model is used. Each of the components of this model (transmission line, circu