Analysis of Insulation Degradation in Low Voltage Motors Driven by Si IGBT and SiC MOSFET Frequency Converters

Induction motors driven by frequency converters are present in many applications in the industrial environment, and have gained strength in electric traction systems. In systems with higher voltage, more efficient and more compact, converters based on Silicon (Si) IGBT are being replaced by converters based on Silicon Carbide (SiC) MOSFET. This happens due to the possibility of working with higher switching frequencies, which results in lower losses and higher power densities in the frequency converter. Converters based on SiC produce voltage pulses with shorter rise times than those presented by converters based on Si, increasing the stresses on the insulating systems of the motors, especially those built with random windings at low voltage [1] .