In this paper, we present our research into the interruption performance of vacuum circuit breakers in aviation intermediate-frequency (360 Hz to 800 Hz) power supply systems. Intermediate-frequency vacuum arc experiments were carried out in interrupters with a diameter of 41 mm and CuCr50 alloy contact material. The results show that, as the frequency and peak value of the current increase, bo...

Circuit breakers (CBs) are the main protection devices for both alternating current (AC) and direct current (DC) power systems, ranging from tens of watts up to megawatts. This paper reviews the current status for solid-state circuit breakers (SSCBs) as well as hybrid circuit breakers (HCBs) with semiconductor power devices. A few novel SSCB and HCB concepts are described in this paper, includi...

The paper presents the required parameters in the evaluation of the technical state for the High Voltage (HV) circuit breakers. It details some aspects regarding the influence of the kinematics characteristics to the circuit breakers performances. Also, it presents a possibility to use the artificial neural networks (ANN) in the analysis of the circuit breakers kinematics characteristics, in or...

Exchanges adopted several circuit breakers and program trading limits following the 1987 Stock Market Crash. The intended purpose of these policies was to reduce volatility. Unfortunately, there has not been enough extreme volatility to conclusively determine whether they have been effective. The lack of volatility does not demonstrate their effectiveness since extreme volatility is very rare. ...

This paper will discuss the importance of reliable and repeatable performance of molded case circuit breakers in today’s power distribution systems. The paper will review existing standards for maintenance of molded case breakers including procedures outlined in NEMA AB4 and IEEE1458. Common misconceptions and system application issues regarding these devices will be discussed. Several examples...

A power system is considered to be transiently stable if it can regain and maintain synchronism after a sudden disturbance. Circuit breakers play a pivotal role in maintaining transient stability of power systems. Using high speed circuit breakers, transient stability can be achieved efficiently in power systems. The project has aimed at the improvement of the transient stability using high spe...

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-...