Alongside digitalization and artificial intelligence, energy supply with direct current (DC) was one of the key topics at the Hannover Messe 2019. The ZVEI had set up a pavilion specifically for this purpose, and Lapp presented its first products in its futureLab. The specialist for integrated cable and connection systems is a pioneer in this field. As an associated partner in the DC Industry research project, the company is working on the question of how DC voltage networks with central conversion can be established as an energy-saving alternative, particularly for drives in production, and how renewable energies can be better integrated. In this ambitious project, Lapp is looking into the suitability of certain cable types and the development of cables that are suitable for DC networking.

First products presented

Such cables are already available in Lapp's portfolio. The first on the market specifically for direct current is the Ölflex DC 100. The color coding of its cores follows the DIN EN 60445 (VDE 0197):2018-02 standard for direct current cables, which was updated in February 2018: red, white and green-yellow. The insulation of the cores is made of special PVC, the sheath is made of PVC. Other cables include the Ölflex DC Servo 700 with special PVC insulation and the DC Chain 800 with TPE insulation for continuous movement in energy supply chains. Lapp has also developed the Ölflex DC 100 Hybrid, a cable for the DC industry consortium. The DC hybrid cable contains two cores for power transmission plus a protective conductor, a Cat.6A data cable with four shielded wire pairs, two cores for Safe Torque Off (emergency stop) and a 24 V control pair for the brake.

A DC energy supply can play an important role in a successful energy transition. This is because it is not just about generating as much renewable energy as possible, such as solar and wind energy. Significant and often overlooked potential for switching to a sustainable energy supply also lies in saving energy. Direct current is a key here, as there are no losses when converting between AC and DC. The automotive industry has recognized this. There are already pilot projects there to supply production cells and later entire factories with direct current only.

Relief for the power grid

A direct current supply is also a prerequisite so that drives can feed energy back more easily when braking. As with electric or hybrid cars, this energy would be stored in batteries until the drive accelerates again. Both drives and batteries consume direct current. This energy buffer can be used to supply power consumers with high power requirements, for example during welding. This would allow companies to cut peak loads and avoid having to draw large amounts of energy from the grid for short periods.

Not only industry, but also households would benefit. Many electrical consumers, from LED lights to electric cars, actually work with direct current, which previously had to be converted from alternating current from the socket. In addition, more and more systems that generate direct current, above all photovoltaics, are feeding into the increasingly decentralized electricity grid.