Vacuum interrupters, the new technology for switching and protecting distribution circuits

Abstract

rhis paper will provide application guidelines for, and will show the advantages of, applying vacuum interrupters to switch and to protect power distribution circuits. The performance of vacuum interrupters for load switching and for short circuit interruption will be discussed with reference to long term switching life and low maintenance costs. During this discussion the unique ability of the vacuum interrupter to handle developing faults will be analyzed. The effects of current chop and voltage escalation on the components in a distribution circuit will be examined, and straightforward methods to minimize their effects will be presented. The advantages of using vacuum interrupters for long life, maintenance free performance for capacitor switching and for motor switching will be discussed. The paper will discuss the very fast recovery characteristics of vacuum interrupters, and will show how these characteristics can be used to produce a circuit breaker that will reliably protect distribution transformers. Finally, the use of vacuum interrupters for other switching duties will be examined.

Study on the Influencing Factors of Reignition Characteristics for 40.5kV Vacuum Circuit Breakers

“…As a result, the best scope of clearance between open contacts is found. The interrupters have been used widely to switch and protect distribution circuits [ 1]. Vacuum circuit breakers, in contrast to other circuit breakers, possess the following features [2].…”

Investigation of the circuit breaker reignition overvoltages caused by no‐load transformer switching surges

“…The effect of multiple reignitions and voltage escalation can be limited and eliminated by protective de- vices: an R-C suppression branch set as close as possible to the terminals of the inductive load. Also a series connected capacitor and a resistor (the resistor connected in parallel to a ZNO varistor) and surge arresters [22]. Several models have been introduced for the modelling of the surge arresters.…”

Improved Calculations for No Load Transformer Switching Surges

“…This becomes clear when dealing with small inductive current switching in relation to the unstable arc burning around current zero. The chopping current is a parameter that has been extensively studied and the latest generation of VCBs have significantly reduced the mean chopping current level [12], [18]. In three-phase circuits the situation is more complicated because of the capacitive and inductive coupling of the load.…”