Lightning damage frequently remains undetected in wind turbines, 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 A is the chief 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 frequently fail to detect this form of lightning. DEHNdetect is a lightning current measuring system for detecting lightning events. It has been designed to register these long stroke currents on wind turbines, as well as impulse current, in order to prevent the need for expensive maintenance work and long downtimes. 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 systems. 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 even 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 you in the SCADA system or online,” clarifies Vögerl. “The benefits include always being up-to-date with the system, being able to prevent subsequent damage, having lower maintenance and repair costs, and experiencing less downtime.”

“DEHNdetect keeps you informed about what is going in your wind turbines, whether for an individual turbine or an entire wind park, giving you continual data on the condition of your components. This includes the option of setting up push messages to be sent directly to your smartphone or tablet. The system allows you to invest in availability and make your wind turbines a reliable source of power, both now and in the future,” he concludes.