High-Power-Density Fault-Tolerant PM Generator for Safety-Critical Applications

Many safety-critical applications particularly in aviation require high-power (mass)-density generators with high reliability. While permanent-magnet (PM) machines promise significant improvements in power density and reliability, the widespread use of PM generators has been hitherto limited by the potentially detrimental effect of internal machine faults caused by the lack of de-excitation capability during fault conditions. Although there are several publications addressing fault-tolerant PM machines, most of these target auxiliary systems. In this paper, the detailed analysis, design, and test results of a 175-kW main power fault-tolerant embedded PM generator for aerospace applications will be presented. The design tradeoffs and the novel aspects of this machine will be discussed in detail.