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. SIEB & MEYER frequency converters of series SD4M are specially designed for high-speed applications and use the innovative three-level technology – also called multi-level technology.
The SD4M devices follow the successful SD2M series and are designed for stationary use in control cabinets of turbo compressors as well as for applications such as ORC, gas expansion and flywheel.
The Top Booster
The three-level technology is of great advantage in these applications because in most cases the SD4M 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 and optionally up to 32 kHz as standard. The combination leads to a considerably improved motor current quality, which significantly reduces the undesired rotor losses – by up to 90 %!
|Standard converter |
Two-level PWM with motor choke
|Standard converter |
Two-level PWM with LC filter
|Small installation space||✓||X||X|
|No risk of resonance effects||✓||✓||X|
- Function: The output stages of SD4M 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.
- 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.
Our Experience in High-speed Technology - Your Advantage!
Up to 60 % reduced installation space for the required electrical components
Improved availability due to the reduced number of components
Up to 50 % reduced weight for the required electrical component
Reduced environmental footprint due to lower energy consumption
Significantly less wiring- and assembly work
Connectivity for the future Ethernet/web server/EtherCAT/Modbus
Cost reduction for IPM the drive chain
Maximum performance of IPM motors through dynamic operating point control
Improved efficiency of the overall system
Motor Currents by Comparison
Good to Know
- Currently available power classes from 100 to 500 kVA, with up to 800 Aeff rated current.
- Liquid cooling as standard (water-based), air cooling on request
- NRTL/CSA certified
- Very low insulation stress on the motor winding - even with long motor cables - due to 50 % smaller PWM switching amplitudes (see graphic below)
- Optional DC power supply for active magnetic bearings, via internally fused DC link terminals
- Designed for 100 % utilisation 24/7
- All power components designed for 10 years continuous operation at rated load
- Designed for worldwide 3-phase supply networks - also potential-free IT
- Powerful parameterisation and diagnostic software drivemaster4
- Customer-specific solutions can be realised
- 3C3 protective coating of the printed circuit boards for operational safety in aggressive environments
- Mains voltage
- Logic board
- Motor connection
- Liquid cooling
Drive Functions and Safety Functions
Simulation, commissioning, monitoring: drivemaster4
- Electrical operating points
- Influence of PWM frequency/inverter topology
- FFT analysis including THDi/THDu calculation
- Export of simulation data
- Parameterisation of the motor data/interfaces
- Optimisation by means of oscilloscope
- Commissioning tool
- Data logger
- Real-time clock
- Error memory
- Operating hours counter
Technical Specifications of Frequency Converter SD4M with 3-phase AC Mains Voltage without Brake Chopper
|Device type||Nominal power1||Nominal current||Max. Output voltage1||HxBxT (mm)||Weight||Cooling|
|Compact units - 3 x 200...480 VAC mains voltage|
|120 kVA||165 Arms||3 x 410 VAC||685 x 388 x 188||30 kg||Water 2) 4)|
|180 kVA||255 Arms||3 x 410 VAC||771 x 439 x 207||43 kg||Water 2) 4)|
|228 kVA||310 Arms||3 x 410 VAC||771 x 439 x 207||43 kg||Water 2) 4)|
|342 kVA||480 Arms||3 x 410 VAC||1317 x 326 x 489||94 kg||Water 2) 3)|
|438 kVA||630 Arms||3 x 410 VAC||1317 x 326 x 489||94 kg||Water 2) 3)|
|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 with mains voltage/supply voltage printed in italics.
2) Cooling tubes aluminium
3) Copper cooling tubes
4) Air-cooled variants and variants with other cooling tube materials on request.