FPGA-based implementation of sensorless AC drive controllers for embedded electrical systems

The aim of this paper is to present a FPGA (Field Programmable Gate Array (FPGA) based implementation of sensorless speed controllers for an embedded aircraft electrical system composed of a Brushless Synchronous Starter/Generator (BSSG). To eliminate the mechanicals sensors, the proposed strategy provides position estimation based on two sensorless approaches depending. For very low speed and standstill, the injection of a rotating high frequency voltage in the vector control scheme is validated experimentally with BSSG. For low and high speed, an Extended Kalman Filter (EKF) algorithm is used. As first step of validation, the experimental results were performed with a Standard Synchronous Actuator (SSA). Experimental results prop up the efficiency and the interest of using FPGAs in such application. In order to evaluate the features of a system-on-chip (SoC) approach integrating a soft processor core, a HW-SW (Hardware-Software) partitioning has been performed using the EKF-based sensorless speed controller. An optimization algorithm NSGA-II (Non-dominated Sorting Genetic Algorithm) is used to find the optimal partitioning of control modules regarding constraints (time/area).