EMSA just released a new report with the results of a test series of industrial Silicon Carbide Variable Speed Drives, revealing clear efficiency advantages, but also the need for further research on challenges.

The investigation of Silicon Carbide Variable Speed Drives shows promising efficiency gains at higher switching frequencies, but only up to a certain limit. While reducing current harmonics lowers motor losses, excessive switching frequencies cause Variable Speed Drive switching losses to dominate, ultimately reducing overall efficiency.

Studies on partial discharge effects in windings confirm that Silicon Carbide Variable Speed Drives can produce higher overvoltage at motor terminals due to faster voltage rise rates. This can accelerate the ageing of winding insulation, particularly when existing Variable Speed Drives are replaced without corresponding motor-side adjustments. Increased bearing currents have also been observed, though their impact strongly depends on bearing type and operating conditions.

Despite the theoretical benefits of Silicon Carbide technology, long-term tests have revealed reliability issues in currently available Variable Speed Drives. This highlights the need for further research into the robustness and industrial suitability of wide-bandgap semiconductors. A comprehensive research roadmap is presented, as a crucial step toward resolving open questions surrounding the adoption and optimisation of wide-bandgap technologies in industrial drives.

For more details, download report.