Zbigniew Wróblewski

Analysis of a forced extinction of a diffuse vacuum arc for digital modelling purposes

The decay time of electron current in the post-arc phase after a forced interruption of a diffuse vacuum arc were measured experimentally. Arc current of amplitude 400 A was switched-off using counter-pulse currents with failing rates from 3 A//spl mu/s u to 30 A//spl mu/s. The decay process of electron current was observed using a Langmuir probe. The decay times of electrons of mean values from 4.5 /spl mu/s up to 6 /spl mu/s were measured Considering the flying times from the contact edge to the probe at current zero, the decay times of electrons can be estimated in the, range from 0, 5 us up to 3 /spl mu/s. These values are proposed as electron deceleration time in modelling of post-arc phenomena for low voltage vacuum switches.

Magnetic field 50 Hz: Its influence on living cells HL-60: Basic tests which have a practical application

Many experimental studies have proved that magnetic field of 50 Hz frequency is not neutral to living organisms and may induce in them a variety of measurable changes. This paper presents research into the impact of magnetic fields 50 Hz on human living leukaemia cells HL-60. These studies were carried on in cooperation with the University of Wrocław.

Overvoltage and overcurrent in a capacity circuit generated by a vacuum switch

This paper presents the result of studies about overvoltage and overcurrent in a capacity circuit generated by a vacuum switch. All study was done in simulation in EMTP/ATP program. A model was built for simulating switching operations, disable capacitor bank with and without reignition of vacuum arc.

Review of Structural Solutions in High-Voltage Overhead Power Lines and Possibilities of Reducing Emission of Electromagnetic Fields

This article compares the electromagnetic field distribution in the environment of overhead power lines built based on typical constructions of poles to be built as pipe–poles. On the basis of the distribution of digital simulation of the electric fields and magnetic fields specified range of the impact on the environment of overhead power lines. In conclusion, a proposed structure which the areas management under overhead power lines is optimal.

Surge protection in capacitive circuit with a vacuum switch

This work presents results of studies about protection 3-phas capacitor bank before very dangerous overvoltage and overcurrent generated by a vacuum switch. For the protection used to varistors in three possible combinations when the neutral point of capacitor bank is insulated The study compares presented methods and gives the answer which one is the best. All results comes from simulations in ATP/EMTP program.