A new resonant link aircraft power generating system

A 400 Hz aircraft power generating system which has been designed to achieve significant improvements in power density and reliability is introduced. Design targets for this exploratory development program include system (generator-plus-converter) power density of 1 kVA/lb and mean-time-between-failure (MTBF) of 500 h. At the heart of the new variable-speed constant-frequency (VSCF) configuration is a high-frequency resonant link inverter designed so that all inverter switching occurs under zero-voltage conditions. Advantages include minimization of switching losses and significant reductions in power device switching stresses and electromagnetic interference (EMI) generation. Inverter losses are further reduced by using MOS-controlled thyristors (MCTs) as the power switches in order to take advantage of their low forward voltage. A 60 kVA breadboard version of the system has been constructed, and test results which confirm its key performance characteristics are presented