Control Design for PMM-based Starter Generator System for More Electric Aircraft

The paper deals with the control design of aircraft starter-generator system based on permanent magnet machine fed by active front end rectifier. The analysis of the starter-generator system can be split into 2 parts; starter and generator mode. Their respective control structures are proposed along with mathematical equations that represent the power system. Direct current field weakening method is selected for this high speed application while DC current control is considered during the generator mode. The nature of dynamic limiter employed along with the field weakening controller creates 2 states of operation. Linearized open loop plant models for both starter and generator modes are derived. The plants are verified with equivalent linear and non-linear Simulink models. Appropriate controllers are designed based on the closed loop analysis.