Improved traction efficiency
According to an expert from Bombardier, the efficiency of the IGBT at payload
is about 5 - 6% better than the efficiency of the GTO (95% vs. 90 % efficiency).
The effect on energy efficiency in real operation maybe even bigger due to the
fact that the relative advantage of IGBTs over GTOs is even higher at low loads.
This may push the efficiency gain even beyond 10%. for instance, Japanese JR
Hokkaido claims that IGBT controlled 3-phase AC motors save 15 % energy compared
to their GTO predecessors.
Mass reduction
IGBT modules are generally lighter than GTO modules (some 30%). This may
offer constructive advantages but is negligible for energy
efficiency. |