Customer application

Clever Solution for the Power Grid vs Lightening

Maintain the voltage! That is the highest priority for the lightning protection expert DEHN, even with significant load flow fluctuations and lightning strikes. That’s why WAGO relies on DEHN components for equipping location network stations with control technology. The benefit for customers: perfectly tailored solutions, as well as increased efficiency and reliability – both technical and financial.

Dark clouds are gathering on the horizon; a quiet of rumbling of thunder can be heard in the distance. Then the first lightning strikes flicker in the sky – and suddenly the storm erupts. Several hundred thousand thunderstorms a year occur in Germany, with up to two million lightning strikes.

Some of them reach currents over 100,000 amperes, or even higher. The voltage often reaches of millions of volts or more. Without sufficient lightning and overvoltage protection, electrical devices, systems and equipment can sustain significant damage even during minor storms.

Product Overview

The Energy Transition Increases the Need for Protection

Distribution system operators have not had to worry about their over 600,000 local network stations around Germany, since there are simply no electronics installed there that could be endangered by a lightning strike. The energy transition is now changing that: The volatile feed-in to the distribution grids is increasing, and the fluctuations of the load flows are becoming ever greater, as are the associated voltage fluctuations.

It is crucial to upgrade location network stations: with “intelligent” electronic components such as communication and telecontrol technology, controllable local network transformers and longitudinal voltage regulators or remote controllable load break switches and circuit breakers on the medium voltage level. Tools like these help the network operators keep the power grid stable.

The crux of the matter is that the more electro-technical equipment and devices that are installed in the local network stations, and the more complex and interconnected the local power supply becomes, the greater the risk is of damage due to lightning. As the interface between the medium and low voltage network, the local network stations are especially at risk in this regard.

Lightning striking the equipment or in its immediate vicinity is not the only danger; the interference pulses can also be transferred through the incoming supply lines. Depending on soil conditions and other factors, the hazard radius can extend up to one and a quarter miles (two kilometers) around where the lightning strikes.

Maximum Safety in the Smallest Package

In many of the local network stations that are already equipped with intelligent technology, WAGO controllers organize the communication between the individual primary components. The measurement, control, regulation and telecontrol technology from WAGO allows network operators to react automatically to voltage fluctuations or other deviations. Thus WAGO helps companies ensure the highest reliability and quality of the supply at all times despite significant feed-in and load flow variation.

But what about lightning strikes? To guarantee the network operators safe, fault-free operation of the controllers for this as well, WAGO has brought in an experienced partner for overvoltage protection: DEHN from Neumarkt in the Upper Palatinate, a family company with about 1,800 employees worldwide that has developed and produced lightning and overvoltage protection solutions for over a hundred years.

DEHN’s philosophy is to produce nearly all the required components itself. The company also tests the protective effect of the products in its laboratory before they ship. “That provides customers with the greatest possible safety,” explains Tobias Kerschensteiner, Business Development Manager at DEHN.

Besides surge suppression devices for energy technology, WAGO also uses products from this partner that are specially tailored to wireless applications for device and antenna interfaces with coaxial connection technology. Together they offer protection that safely discharges voltage spikes before they can damage the controllers. The DIN-rail mounting of the DEHN surge arrester saves space and helps WAGO design very compact solutions.

Predictive Maintenance Increases Efficiency and Reliability

The WAGO controller makes it possible to integrate DEHN’s protection solutions into the network operator’s control system. “That is a great advantage with respect to predictive maintenance,” says Kerschensteiner. “It allows network operators to check from the control room whether the overvoltage protection is functioning properly.” Technicians only have to visit the plant if a problem actually exists there or could exist within a foreseeable amount of time.

Thus companies can forego routine on-site checks. This is a big win for the network operators, since many of them do not even have enough qualified employees to handle such tasks. “Remote access to the operating data makes the maintenance of the protective equipment very efficient without compromising safety,” explains Kerschensteiner.

Since October 2016, the products have met the applicable standards – VDE 0100-443 and VDE 0100-534. These set new requirements on the protection of electrical equipment and systems against overvoltages that can be caused by atmospheric effects or switching operations.

From a Product Supplier to a Solution Supplier

However, the optimal form of a protection concept depends heavily on the local conditions. Therefore, Kerschensteiner emphasizes, customers are not served with standard products, but rather receive individual advising. “Together with WAGO, we can offer network operators tailored solutions,” adds the DEHN expert. This strategy is advantageous for customers, since they run technical equipment like local network stations for very long periods. Kerschensteiner goes straight to the heart of their claims: “DEHN and WAGO offer more than just products – we are solution providers!”

Text: Daniel Wiese | WAGO
Photo: Ralph Diermann | Fotolia

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