The electric current is omnipresent and indispensable in our life. But there are always threatening dangers connected with it. One of them is the electric short circuit and we have to protect people and facilities from its effects. This protection is often provided by power circuit breakers or motor protective circuit breakers. These devices are able to detect the short circuit, limit the curre...

 The use of MEMS electrical switches as miniature electrically resettable circuit breakers is described. A prototype based on nickel thermal actuators on silicon has been fabricated and tested, and the performance is compared to analytical models. Trip currents of ≈ 300 mA are obtained, with trip times less than 50 ms. Temperature dependence of trip current is shown to be below 0.2%/K. The rel...

nowadays, high-voltage circuit breakers have reached such high short-circuit capabilities that testing them under the full rated voltage is generally not possible with direct tests, and they are conducted by using the synthetic test methods. although the phenomena associated with making tests is of particular importance especially in case of load break switches, but making tests are rather disr...

ENGLISH) Motivated by economic pressures, power utilities are increasingly looking for new ways of reducing their costs while maintaining the quality of supply. A promising concept is predictive or condition based maintenance of high voltage equipment, based on continuos knowledge of each device’s condition. Power transformers and high voltage circuit breakers (HVCBs) have been the focus of att...

The paper discusses the design of a flexible pulsed current source needed for experimental research of switching arcs in HVDC circuit breakers with passive resonance circuits. The source drives a current pulse from a pre-charged capacitor and forms it using an IGBT switch operated at 10kHz. The current source will be used to measure stationary and transient UIcharacteristics of switching arcs i...

Using the Vibration signatures obtained during the operations as the original data, a mechanical condition monitoring method for vacuum circuit breaker is developed in this paper. The method combined the time-frequency analysis and the condition recognition based on artificial neural network. During preprocessing, the vibration signature was decomposed into individual frequency bands using the ...