Variable frequency drives (VFDs) are a key part of industrial automation machinery. They help drive pumps, fans, conveyor belts, computer numeric control machines and robotic automation solutions efficiently, helping reduce a factory’s total energy consumption. Downtime in a VFD directly translates to machinery downtime, which can lead to factory shutdown and a loss of production. VFD reliability and robustness are key requirements for machine builders and factory owners.
The three-phase inverter structure shown in Figure 1 is the heart of a VFD, converting the rectified mains voltage into a variable frequency and a variable voltage output to the motor. Inverter robustness is a key contributor to the robustness of a VFD.