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Flywheel Energy Storage Units,
ORC and Gas Expansion Turbines

The optimal products for your flywheel energy storage units, ORC and gas expansion turbines

For motor-driven and generator-driven high-speed applications with high output powers the available standard converter solutions are not sufficient. Up to now converters for output powers > 100 kW and rotating field frequencies > 2,000 Hz were not available on the market – let alone solutions also capable of controlling synchronous motors without sensor.

Due to the German turnaround in energy policy, today such systems are in demand: they enable a significant increase in the efficiency of regenerative systems such as rotating energy storage units (flywheel) and turbomachinery like turbo compressors and other compressors, e.g. for ORC systems to convert waste energy into electric energy. The higher the speeds, the more efficient the systems work.

SIEB & MEYER frequency converters with three-level technology meet these requirements and also ensure low rotor losses. This reduces the bearing load and prevents excessive heating of the motor.

Product Overview


Device series Power range Input voltage Technology Speed (ferquency) Type Communication Safety functions
SD2 1 .. 80 kVA .. 750 VDC 2 Level PWM 120,000 1/min
(2,000 Hz)
Single-axis unit with external DC supply RS485, via Gateway: Profibus, Profinet, EtherCAT STO
SD2M DC 80 .. 432 kVA .. 750 VDC 3 Level PWM 120,000 1/min
(2,000 Hz)
Single-axis unit with external DC supply RS232/485, Modbus RTU, CAN Bus, EtherCAT, via Gateway: Profibus, Profinet STO
  • Drive System SD2

    The Team Player

    The digital drive system SD2 can be connected to your controller via the real-time bus SERVOLINK 4 using fiber optic cables. This design allows a direct and fast access to all relevant drive parameters.


  • Frequency Converter SD2M DC

    The Powerful One

    SIEB & MEYER has developed the frequency converter SD2M DC using the three-level technology which ensures exceptionally low rotor losses. SD2M DC convinces by a maximum output, little need for space, reduced system costs and high efficiency.

Products precisely tailored for your application

With our experience from customized drive systems that are meanwhile produced in large series and as well as our standard devices, we are supporting you from the project planning phase to the series production.