High power-density fault-tolerant PM generator for safety critical applications

Many safety-critical applications especially in aviation require high power (mass) density generators with high reliability. While PM machines promise significant improvements in power density, and reliability, the widespread use of permanent magnet (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. Even though 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 as well as the novel aspects of this machine will be discussed in detail.