Digital Control of a Brushless Excitation Synchronous Starter/Generator in the Generation Mode

This paper presents a voltage amplitude control of a brushless excitation synchronous starter/generator (S/G) machine, while functioning as a generator. This type of machine is commonly used in the aircraft domain due to its autonomy and robustness. The aim of the control is to maintain constant voltage amplitude on the load terminals by controlling the exciter excitation current. The proposed control is based on hysteresis regulator. This is owed to its robustness towards the variations of the machine's parameters. The control algorithm was implemented on a Field Programmable Gate Array (FPGA) in order to ensure fast computation with an execution time only of a few microseconds. The proposed control was experimented on a low scale model prototyping platform, which emulates the brushless excitation synchronous machine of an aircraft. Numerous experimental results are given in order to illustrate the efficiency of the used FPGA-based solution to achieve high performance control of the brushless excitation synchronous generator.