Continuous optimization and extension
Frequency converter SD2M: operation on unearthed IT networks possible
From the beginning of 2019, some device verions of the frequency converter SD2M by SIEB & MEYER is suited to the operation on unearthed IT networks. This means that device modifications for that purpose, for example hardware changes, become unnecessary. Even now, there is a lot of positive experience with the operation of power ranges up to 300 kW on a 3-phase 480 +10% V IT network.
IT networks are often found in the USA but also in some parts of France as well as worldwide in so-called isolated networks used by the industry. In contrast to the most common TN and TT networks, IT networks have no fix reference to the earth potential so that high-energy interference components cannot be discharged. This results in considerable problems with the isolation of devices and often causes interference. "Therefore, many manufacturers forbid the use of their converters on unearthed networks from the outset. As an alternative, the devices must be modified extensively," Rolf Gerhardt, director sales drive electronics at SIEB & MEYER AG, explains. "Some device versions of our SD2M, by contrast, will run trouble-free also on IT networks from 2019 onwards."
At the service of its customers, SIEB & MEYER continuously develops the innovative frequency converter with three-level technology. Recently, the Lueneburg based company has, for instance, extended the performance spectrum of SD2M as basis for customized solutions. Now, the company can implement customized devices with motor currents up to 650 A – either equipped with air cooling or with liquid cooling.
It is not surprising that SD2M has been writing a success story in the few years since its introduction: SIEB & MEYER won numerous new customers for series production, for example in the field of high-speed turbomachinery such as turbo compressors, turbo blowers and turbo generators. Besides, the frequency converter SD2M is still the first choice for machine tool applications or test stations where it proves itself by maximum output at minimum required space, reduced system costs and high efficiency. SD2M comes with the innovative three-level technology designed for output powers up to 432 kVA and rotating field frequencies up to 2,000 Hz.