Electricity + Control October 2019

Product News EARTHING + LIGHTNING PROTECTION

Identifying lightning damage in wind turbines Lightning damage in wind turbines frequently remains undetected as it often does not lead to the immediate failure of the system. Upward lightning – or ground-to-cloud lightning – with an initial long stroke current of only a few hundred Amps is the main cause of damage such as melting on the receptors of the rotor blades. In the long term, this damage can lead to turbine failure. Florian Vögerl, Head of Sales and Operations at DEHN Africa, says, “Due to the low current flow of upward lightning, standard measuring systems often fail to detect this form of lightning. DEHNdetect is a lightning current measuring system for detecting lightning events. It is designed to register these long stroke currents on wind turbines, as well as impulse currents, in order to prevent the need for expensive maintenance work and long downtime. DEHNdetect can also be equipped with optional rotor blade detection.” The system can be integrated into the IT infrastructure of the wind turbine via existing interfaces. The data can then be read out and managed using the available SCADA system. If direct integration is not possible, the data can be transmitted to a cloud system and evaluated via a web application. This makes it possible to monitor several turbines or entire wind parks. DEHNdetect identifies the following parameters: - Impulse current [kA] - Long stroke current [A] - Load [C] - Specific energy [MJ/ Ω ] - Rise time [kA/μs]. “DEHNdetect identifies the affected rotor and notifies the user via the SCADA system or online,” says Vögerl. “The benefits for users include always being up-to-date with the system, being able to prevent subsequent damage, as well as lower maintenance and repair costs, and less downtime. “DEHNdetect keeps users informed about what is going on in the wind turbines, whether for an individual turbine or a whole wind farm, providing continual data on the condition of the components. It includes the option of setting up push messages to be sent directly to the user’s smartphone or tablet. The system allows users to invest in availability and ensure the wind turbines provide a reliable source of power, now and into the future.” For more information, contact DEHN Africa. Tel: +27 (0)11 704 1487, email: florian.voegerl@dehn-africa.com

DEHNdetect is designed to register upward lightning currents in wind turbines so that damages can be identified and repaired before they lead to turbine failure.

Electricity + Control

OCTOBER 2019

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