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Multilevel Frequency Converter SD2M with DC Supply

Press releases

Expansion of the power range

SIEB & MEYER AG has expanded the application range of the three-level frequency converter SD2M by device variants with DC supply and an output power up to 500 kVA / 800 A. In combination with the existing device variants, manufacturers in the field of regenerative applications can benefit from the three-level technology across their entire range of products.


The DC variants of SD2M are suitable for applications, in which process energy or stored energy of high-speed motors/generators is fed back to the grid. For this purpose, SD2M is combined with a grid-tie inverter (active front end power supply) that is usually subject to country-specific and grid-specific requirements. Typical applications are ORC systems, flywheels and other turbine-based generator systems.

In these application fields, the three-level converter series SD2M with DC supply offers significant advantages: particularly the dynamic and sensorless control technology of SD2M as well as output stages specially designed for high-speed applications are key factors here. Compared to standard frequency converters, the series SD2M scores with distinct advantages in terms of efficiency, size, weight and costs for the respective overall system. In most cases, expensive additional components are not required, for example motor LC filters or motor chokes. Additionally, the separation of grid-tie inverter and frequency converter at DC link level makes the global use of the products much easier. Different grid requirements can be fulfilled by using local grid-tie inverters without negatively affecting the high-speed motor, which is often very sensitive.

At the end of 2023, the DC variants will be available with the new SD4x logic platform. Then, users will also profit from the latest improvements in the control technology regarding IPM motors and connectivity.