Effect of IGBT switching dynamics on loss calculations in high speed applications

The switching and conduction loss in bipolar devices are dependent on the switching intervals, especially when these intervals become small enough to prevent the device from reaching steady-state conditions. This behavior is quite pronounced for non-punch-through IGBT´s, and is found to drastically decrease the overall switching loss of these devices in high frequency applications relative to values projected from conventional approaches. It also results in an unexpected dependence of net losses on duty cycle. The reasons behind this behavior are examined, and its implications for semiconductor loss calculations are discussed.