Development of an Algorithm and Research of Features for Selecting Devices to Protect Electric Circuits from Surges Caused by Thunderstorms

Lightning strokes can cause considerable voltages in constructions of buildings, facilities, equipment. That may result in sparking, disruption to power supplies of electric energy consumers, equipment breakdowns etc. That is why it is strongly recommended (sometimes even compulsory) to install surge protective devices. Buildings and facilities (or their parts) depending on their purpose and thunderstorm intensities in the region they are located in, should be protected both from direct lightning strokes and from lightning secondary effects. The lightning protection project should have projects both for external and internal lightning protection systems. The paper suggests a algorithm for calculating the main of surge protective devices parameters are class, impulse current, nominal discharge current, maxi-mum discharge current, open-circuit voltage, maximum continuous operating voltage, maximum continuous operating current, voltage protection level, follow current, temporary overvoltage and response time. For microelectronic equipment the voltage protection the zone-selective system is required. The presented paper suggests an algorithm for selecting surge protective devices for power supply circuits of electrical energy consumers in order to ensure reliability of energy supply in conditions of thunderstorm activities. The algorithm is suggested with account of the requirements of relevant European and American standards. A study of features for selecting devices to protect electric circuits from surges caused by thunderstorms. For illustrative representation of implication of the suggested algorithm a functional mock-up for surge protection of a single-phase consumer at its plugging into the mains.