Abstract:
The present thesis wishes to offer a possible solution for the automotive
air conditioning compressor electric motor drive. The low cost, high efficiency,
compact size and practical implementation constraints are considered for the two
major research direction that arrise- motor design and control strategy.The
thesis includes the design methodology for a 6 slots/ 8 poles 3 phase permanent
magnet synchronous actuator with surface permanent magnets. Classic
electromagnetic design is followed by the optimization design stage based on a
modified Hooke-Jeeves method and FEM inspection. Furthermore, because the
cogging torque and total torque ripples are not satisfactory, a FEM embedded
hybrid design procedure is defined, that uses FEM calculated values and underrelaxation
coefficients to go back and correct the geometrical/ electromagnetic
variables that have major impact upon the aforementioned characteristics. A
new sensorless control strategy, based on six-step commutation and trapezoidal
current command is proposed. The necessary information is obtained by
processing only the current and voltage measurements data from the d.c. link.
The proposed method is conceived to comply with the air conditioning
compressor drive requirements, but may be applied to other systems with similar
characteristics.
