Sensorless Control of Six-Phase Permanent Magnet Synchronous Machines

This thesis proposes a complete study of the cross-coupling effect between d- and -q axes for six-phase IPMSMs to develop a real-time FPGA-based emulator considering the nonlinearity of the system. The main aim of this work is to improve the performance of existing sensor-less Dual Three-Phase (DTP) Interior Permanent Magnet Synchronous Machine (IPMSMs) Drives. This study and implementation helps improve the efficiency of the system, power rating up to 10 MW and the system redundancy. Additionally, having a complete and robust real-time emulator in the lab drastically helps in the educational process and in future researches, as the cost and consumed-time in doing experiments using physical systems reduces. The current and flux are used as state variables in investigating the effect of d- and -q axis currents on the flux linkages in q- and -d axes. Furthermore, a polynomial model is developed and curve fitted to establish a relationship between the currents and flux linkages of d-and -q axes. This model calculates the currents as a function of flux linkages and vice versa. The next step after improving the model in Simulink is to modify the real-time emulator model, and this is achieved by modifying the IP-Core emulator in Simulink and exporting it to IP-catalog in VIVADO. The results show that the system responses in ideal and nonlinear models in Simulink and the linear and nonlinear emulators have approximately the same behavior from the control point of view. However, in nonlinear models, the flux linkage in q-axis is greatly affected by d-axis current.