Design and control contributions to high efficiency Ferrite-PMSM drives for small compressors

Abstract

This thesis presents and investigates several new motor topologies, candidates for driving small compressor applications for home appliances, for ratings: 35-1000W, 1600-4500rpm. Their operation principles, main characteristics and advantages are investigated and discussed. FEA assisted or full FEA optimal design methodologies are developed with the design target of maximize the efficiency and minimize the motor cost. The optimized motors are validated via finite element analysis and simulation of the dinamic operation under proposed close loop control simple strategies. This work is also focused on investigating sensorless control strategies for 3 phase permanent magnet synchonous motors applicable for compressor applications. The V/f scalar control with active power variation and MTPA operation based stablilizing loops is investigated and compared against the classic sensorless field oriented control strategy, via experimental and digital simulation. Active flux model-based observer is employed for rotor position and speed estimation. The target is proving that the scalar control is suitable for being used in home appliances applications.