Since the May 6 th , 2010 flash crash in the U.S., appropriate measures ensuring safe, fair and reliable markets become more relevant from the perspective of investors and regulators. Circuit breakers in various forms are already implemented for individual markets to ensure price continuity and prevent potential market failure and crash scenarios. However, coordinated inter-market safeguards ha...

The general trend in electrical appliances is to go for electrical equivalents of mechanical or electromechanical gadgets. One of the long standing electronic component is the circuit breaker, a protective device that trips the ac supply once the current through the system goes beyond the rated value. In this paper an all electronic circuit breaker using bidirectional switch is demonstrated. Th...

This paper describes a three-dimensional thermal model of the current path included in the low voltage power circuit breakers. The model can be used to analyse the thermal behaviour of the current path during both steady-state and transient conditions. The current path lengthwise temperature distribution and timecurrent characteristic of the terminal connections of the power circuit breaker hav...

Very low temperatures stress a circuit breaker in a complex manner. Mixed-gas circuit breakers were developed for use at temperatures as low as -50C. These breakers utilize a gas mixture of SF6 and CF4 or SF6 and N2 to prevent condensation of the SF6 gas and have been type tested at -50C to ensure travel characteristics, operating times, and gas tightness are acceptably affected. Today’s mixed-...

This paper is a sequel to a study by the authors of electric power systems comprising the generator circuit-breakers (GCBs) at power plant generator terminals. A sustainable assessment of the current interruption requirements of a GCB addresses the main stresses on the generator circuit breaker, revealing that the GCB current interruption requirements are significantly higher than for the distr...

Circuit breakers can fail to interrupt fault current when the power system has transient recovery voltage (TRV) characteristics that exceed the rating of the circuit breaker. There were two incidents of failures of outdoor switchgear at a power plant substation. The cause of the failure for these breakers was investigated in order to determine if transient recovery voltage is a contributing fac...

To one double-breaker model, experimental investigation on blow open force was carried out. It demonstrates that the ratio between the emerging blow open force and arc power FB/ui decreases with the arcing time, the contact gap has less effect on FB/ui, and the characteristics of the blow open force are similar when the peak value of the short circuit current is beyond 4 kA. Then, according to ...