Minimizes losses, increases efficiency

When developing the SD4M, Sieb & Meyer combined tried and tested technology with the latest control and communication technology. Equipped with innovative three-level technology, the compact frequency converter is not only ideal for use in high-speed turbomachines, but also highly interesting for high-performance HSC milling machines, for example in the aerospace sector. There the SD4M ensures the lowest motor losses and a correspondingly high level of efficiency.

The SD4M variants in the range from 70 to 490 kW or 120 to 800 A nominal current were adopted from the previous SD2M series in terms of power electronics. In the new performance class with 70 kW and 120 A, the SD4M expands the current performance range of the SD2S and SD4S and thus closes the gap in Sieb & Meyer's frequency converter portfolio. An uncomplicated implementation of the SD4M in the higher-level controller is possible via the multi-protocol real-time Ethernet interface available as standard (including Profinet IO, EtherCAT). The device variants with DC supply can be optimally operated via an external power supply capable of generating energy.

The innovative three-level technology of the SD4M paired with device-dependent switching frequencies of up to 32 kHz ensures very good power quality, so that only low losses occur in the motor and the overall efficiency increases accordingly. In this way, excessive rotor heating is prevented without expensive sine-wave filters or motor chokes. In addition, the three-level technology leads to lower stress on the motor insulation.

Optionally, the SD4M can be further optimized for use in turbo compressors and compressors. This makes it possible to supply active magnetic bearings with the necessary DC voltage via terminal connections and to maintain this voltage for braking even in the event of a fault. Another highlight in the SD4M's performance spectrum is the new dynamic control of IPM motors, which offers the customer even more freedom in system design.

In addition to the water-cooled SD4M variants, air-cooled devices are also available upon request. Sieb & Meyer has applied for NRTL/CSA certification for all device variants so that they can be integrated into machines for the US market without additional acceptance.