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Frequency Converter SD2M Turbo

Standard converters in the higher power classes typically use the well-known technology of two-level pulse width modulation (PWM) with max. 8 kHz switching frequency. In most high-speed applications, this requires additional components such as LC filters or chokes to minimize the additional losses in the engine.

Three-level PWM
Standard converter
Two-level PWM with motor choke
Standard converter
Two-level PWM with LC filter
Low weight X X
Small installation space X X
No risk of resonance effects X
Total costs X X



Three-Level Technology

  • Function:  The output stages of SD2M Turbo are based on a three-level technology and provide rotating field frequencies up to 2,000 Hz with switching frequencies of 16 kHz.
  • Advantage:  Reduced motor losses combined with minimum efforts for motor filters and motor chokes as well as low interfering radiation and insulation stress.
  • Benefit:  Low system costs over the whole product life cycle.


  • Function:  The devices reach efficiencies of up to 98 %.
  • Advantage:  The high efficiency of the devices ensures optimal system efficiencies and reduces cooling requirements.
  • Benefit:  Maximum system output and lower environmental footprint due to lower energy consumption.

DC Supply

  • Function:  Active emergency braking and maintenance of voltage supply in case of power supply failure.
  • Advantage:  No separate voltage supply for the magnetic bearings needed.
  • Benefit:  Protection of the magnetic bearings in case of power failure as well as cost savings.

Motor Currents by Comparison

The Booster

SIEB & MEYER frequency converters of series SD2M Turbo are specially designed for high-speed applications and use the innovative three-level technology – also called multi-level technology.

This is of great advantage in these applications because in most cases the SD2M Turbo converters do not require motor filter elements. This additional value is achieved by the three-level technology, as well as the PWM switching frequency of up to 16 kHz as standard. The combination leads to a considerably improved motor current quality, which significantly reduces the undesired rotor losses – by up to 90 %!

Good to Know

  • Currently available power classes from 100 to 500 kVA, with up to 800 Arms rated current
  • Liquid cooling as standard (water-based), air cooling on request
  • NRTL/CSA certified.
  • Reducing the switching PWM amplitude by 50 % leads to very low insulation stress of the motor - even when using long motor cables  (see diagram below)
  • Optional DC voltage supply for active magnetic bearings via internally fused terminals (intermediate DC circuit)
  • Designed for 100 % load 24/7
  • All power components are designed for 10 years continuous operation at nominal load
  • Designed for worldwide 3-phase supply networks - also IT grids without grounding
  • Efficient software drivemaster2 for parameterization and diagnosis
  • Customized solutions can be realized
  • 3C3 protective coating of the PCBs for operational reliability in aggressive environments

The Interfaces of Frequency Converter SD2M for Turbo Applications

  1. USB connection, parameterization, diagnosis and operation
  2. RS232 / RS485 / CAN interface / Modbus
  3. 2 analog reference value interfaces: +/-10 V,  2 analog outputs: 0 to 10 V
  4. Universal Motor Encoder Interface: Hall sensor, linear Hall sensor, magnetoresistive sensor, NAMUR sensor (pulse generator), Sin/Cos encoder
  5. 9 digital inputs and 5 digital outputs
  6. Liquid cooling
  7. Safety integrated "STO": Restart lock to meet category 4/PL e according to EN ISO 13849-1:2015 and EN 61508:2010 SIL3
  8. Motor connection
  9. 2 TTL encoder inputs and outputs
  10. Power supply

Drive Functions and Safety Functions


Software for Initial Operation and Parameterization: drivemaster2


  • Tree-type structure
  • Block diagrams
  • Graphics
  • Interactive help messages
  • Comments
  • „Parameter-Wizard“


  • Without higher-ranking control
  • Visualized reference and actual values
  • Error and status messages


  • 4-channel oscilloscope
  • Zoom functions
  • Trigger functions
  • Long-term recording function
  • Measurements can be saved
  • Diagnosis of the inputs and outputs
  • Bus monitor

Technical Specifications SD2M Turbo
with 3-phase AC Mains Voltage without Break Chopper

Device type Rated power1 Rated current Max. output voltage1 HxWxD (mm) Weight Cooling
Compact devices - 3 x 200...480 VAC mains voltage
0369171AF0200 100 kVA 165 Arms 3 x 410 VAC 685 x 388 x 188 30 kg Water 2) 4)
0369173AF0200 150 kVA 255 Arms 3 x 410 VAC 771 x 439 x 207 43 kg Water 2) 4)
0369173BF0200 190 kVA 310 Arms 3 x 410 VAC 771 x 439 x 207 43 kg Water 2) 4)
0369175AF0100 300 kVA 480 Arms 3 x 410 VAC 1317 x 326 x 498 94 kg Water 2) 3)
0369175BF0100 396 kVA 630 Arms 3 x 410 VAC 1296 x 424 x 359 94 kg Water 2) 3)
0369276BF0200 500 kVA 800 Arms 3 x 410 VAC 1478 x 353 x 596 136 kg Water 2) 3)

1) Rated power and max. output voltage for mains voltage/supply voltage (in italic)
2) Aluminum cooling pipes
3) Copper cooling pipes
4) Air-cooled versions and versions with other cooling pipe materials on request