Three-phase induction motors provide a reliable drive system for the high-pressure pumping stations, which ensure constantly high quality snow on the pistes
In Zell am See, Schmitten AG ensures that the snow on the pistes is of a constantly high quality using 298 snow guns and 86 propeller systems. The snow conditions are a major factor in the success of a ski season. The right technology is essential for those whose job it is to make winter sports an unforgettable experience whatever the weather. Schmitten AG at Zell am See in Austria is well aware of this, and has proved once again with its latest artificial snow project that the white stuff does not necessarily have to fall from the sky. With the energy-efficient drive technology for the snowmaking machines, extending the season will be even more lucrative.
In the Schmittenhöhe ski area in Zell am See, 100 percent of the pistes can be covered with artificial snow. The best conditions for snowmaking are found at temperatures between -5 and -10 degrees Centigrade. Climate change has resulted in fewer cold days, so winter sports operators must constantly invest in the performance of their snowmaking machines. The latest Schmitten AG expansion stage was commissioned towards the end of 2010 and comprises three plant expansions and new constructions. Pumping systems equipped with efficient drive technology from Siemens form the central core.
Simotics three-phase induction motors, that are characterized by high availability and a long service life, are used to drive the massive high-pressure water pumps for producing the artificial snow. Up to 375kW, the upper limit of applicability of the new international efficiency standard, motors are also available off-the-shelf in the high energy efficiency class IE3 which was a decisive factor in acceptance of the drive solution. This was due to the operator's insistence on energy-saving systems, and as a result they are already endorsing these electric motors.
The Sinamics G150 frequency converters used also have a positive effect on the energy balance. In comparison to plants with valve control of the water supply, which are still common in many other winter sports areas, electronic pressure and speed control saves a considerable amount of energy and also reduces the wear in the pumping stations. The devices are supplied in the form of "turnkey" cabinets and, thanks to their high control accuracy, they enable precisely synchronized operation of the water pumps.
The more frequency converters there are in the network, however, the more harmonics there are that require compensation. Schmitten AG has chosen suitable line filters to enable it to comply with the THD (Total Harmonic Distortion) values prescribed by the energy supplier. Their matching and integration in the drive solution has just become easier. Since 2010, Sinamics converters have been available with the option L01, the so-called line harmonics filter. This complete unit is called Sinamics G150 Clean Power and contains the compensation filter as a fully integrated cabinet unit connected between the control section and power section of the converter.
Finally, the safety technology also plays an important part. To produce fine granular snow, the water must shoot through the gun nozzles at high pressure, which means that the pumps have to generate a pressure of up to 100 bar due to the difference in altitude between the station and the mountain peak. If a fault occurs in the equipment unit, rapid shutdown is essential to prevent damage. It is easy to implement the shutdown of individual machines without loss of the complete pumping system, thanks to the fail-safe shutdown feature that is available as an option in Sinamics G150. This enhances the availability of the snowmaking machines and secures artificial snow production at Zell am See for the future.
