Development and laboratory testing of a lightning current measurement system for wind turbines

Abstract

Dimensioning, testing and maintenance of the lightning protection system of wind turbines can be improved using the local distributions of lightning current parameters instead of those on which lightning protection standards rely. This paper presents a prototype system for measuring lightning currents’ waveforms on wind turbines. The prototype is being developed at the Faculty of Electrical Engineering and Computing, University of Zagreb, Croatia. The system's fundamental components are two Rogowski coils and their corresponding integrators. One coil is optimized for lower frequencies and amplitudes, while the other is for higher ones. The cRIO real-time controller is used as an acquisition system, with acquisition logic developed using LabVIEW. The controller has one digitizer for each coil and a GPS synchronization module. The system was tested in the High Voltage Laboratory at University. It was recently installed on an actual wind turbine in Croatia, located in an area characterized by high winter lightning activity. Simultaneously with the prototype measurement system, the lightning activity in the wind turbine micro-location will be monitored by three other systems: the lightning location system, additional lightning monitoring sensors installed in the blades of the same wind turbine and a high-speed camera installed at the wind turbine location.