Application Considerations for Integral Gas Turbine Electric Starter/Generator revisited 892252

The idea of an all electric aircraft (secondary power) has been around for many years. Its benefits in terms of weight and operational cost savings have been in-creasingly better defined over time. Little has hap-pened, however, toward realizing this system, pro-bably, because one of the key components of such a system, the electrical generator has not achieved the acceptance in the engine world to warrant any more definite steps toward the all electric system. Support and size considerations dictate that this generator be integrated into the gas turbine (Integral Starter/Generator - IS/G). The last IS/G studies in the middle and late 70's found that even the best technology of the day, the PMG technology, did not solve all the concerns about its application to the IS/G task.

Developments in the power electronics area since then have made an old electrical machine concept, the switched reluctance machine, a viable alternative for the integral starter/generator function. This “new” system, power electronics and switched reluctance machine, provides acceptable power density, high temperature and speed capability, good reliability and exceptional operational capabilities under partial failure conditions as well as full excitation removal. The impact of this approach on the integral starter/generator function is being discussed in this paper. It should provide a basic buil-ding block towards the all electric engine and remove most of the major stumbling blocks towards its implementation. Some future development direction will also be discussed to make this system optimally adap-table to the application.