| Popis: |
As process interruptions can be very expensive, reliability and availability values of a variable frequency drive (VFD) are often two of the most important requirements when selecting a drive. Reliability figures are hard to compare because methods and values depend on suppliers using different assumptions and definitions of failures. The main medium voltage VSI (voltage source inverter) topologies (3-level, 5-level, multilevel) for oil & gas applications will be compared with respect to their main power components (semiconductors, capacitors, PCBs, etc.) considering component stress and field data experience. The total reliability of these drive systems (including transformers, recooling unit, control cabinet) will be calculated using the same methods and assumptions. |
