fast rise-time voltage surges surges from a circuit breaker closing can lead to an electrical breakdown of the turn insulation in motor srator windings [1]. If the turn insulation is of an insuffcient thickness or has aged in service, the insulation will puncture when a short rise-time voltage surge occurs. Punctured turn insulation allows for a very high circulating current to flow into the af...

Sulphur hexafluoride (SF6) is an inert and non-toxic gas with excellent properties for arc quenching and electrical insulation applications. The main drawback is its high greenhouse potential. In high voltage apparatuses it is used in sealed volumes e.g. in the interrupting chamber of a circuit breaker. Even so, through flanges and o-rings we encounter always a small amount of gas leakage. Ther...

Frequent Switching of arc furnace in steel company causes a great effect on the insulation of arc furnace transformer winding which in turn may causes a shutdown of production for long periods of time. Therefore, it is necessary to study and analyze the causes of these outages and design an adequate protective device. In this paper the transient overvoltage resulted from vacuum circuit breaker ...

Abstract Circuit breaker is an important electrical control on and off in the line, which refers to switch device that can close, load break current under normal loop conditions, abnormal conditions specified time. breakers are divided into high voltage circuit low according their range of use. Low common molded case breakers. Play a protective role safety lines appliances. When fire occurs, ac...

Abstract: In this work, a new method for calculating the parameters of electric arc model for SF6 power circuit breaker is proposed. The methodology consists in the optimization of a theoretical function with respect to a group of model parameters in order to achieve a better approximation to a set of experimental data. The theoretical function is an asymptotic solution of the equation for the ...

This article describes design, operation and experimental testing of a mechanical DC CB (Circuit Breaker) with parallel capacitors. The topology resembles hybrid but there are possible advantages in the costs since main semiconductor valve is replaced capacitors, performance this breaker inserts counter voltage earlier. A detailed PSCAD model employed to support design analyse operating princip...