This chapter first considers the basic principles of current interruption and the influence of the type of fault produced by the connected network. The electrical characteristics of circuit-breakers are described. The formation of an electric arc during the current interruption process is indicated and the significance of the manner in which the arc is controlled and then extinguished is explained. Various means for achieving such control and with different arcing media are considered. Some basic performance limiting factors are discussed. The chapter concludes by discussing some evolving trends in response to various modern requirements such as environmental issues.

Chapter Contents:

• 7.1 Introduction
• 7.2 Principles of current interruption in HV systems
• 7.2.1 System-based effects
• 7.2.2 Circuit-breaker characteristics
• 7.3 Arc control and extinction
• 7.3.1 Gas-blast circuit-breakers
• 7.3.2 Electromagnetic circuit-breakers
• 7.3.3 Dielectric recovery
• 7.4 Additional performance affecting factors
• 7.4.1 Metallic particles
• 7.4.2 High-frequency electrical transients
• 7.4.3 Trapped charges on PTFE nozzles
• 7.5 Other forms of interrupters
• 7.5.1 Domestic circuit-breakers
• 7.5.2 Oil-filled circuit-breakers
• 7.5.3 Vacuum interrupters
• 7.6 Future trends
• 7.6.1 Other gases
• 7.6.2 Material ablation and particle clouds
• 7.6.3 New forms of electromagnetic arc control
• 7.6.4 Direct current interruption
• References

Inspec keywords: gas blast circuit breakers; interrupters; power system faults; circuit-breaking arcs

Other keywords: electric arc; circuit-breaker; gas-blast circuit-breaker; environmental issue; gas-filled interrupter; current interruption process; fault connected network; electrical characteristics

Subjects: Switchgear