Optimal Design of 1 Phase Linear Oscillatory PM Motor Series for Small Compressor Like Drives: With FEM and Self-Starting Transients Validation

Refrigerator compressors are currently driven mostly by rotary line start or variable-speed (inverter-fed) motors with mechanical transmission. Direct driving of pistons by linear oscillatory resonant PM 1 phase motors has just been introduced to low power (less than 100 W) such applications. The present paper introduces a 3 pole PM mover 1 phase PM linear oscillatory motors, in terms of optimal nonlinear analytical design methodology, with FEM and dynamics validation. Both 50 and 250Hz (inverter fed) operation for 2000 and 100W is exemplified for minimum active materials costs and, respectively, minimum global costs (losses capitalized cost is added). For the line start case study (at 2000W, 50 Hz) a circuit model for transients is introduced and the motor self-starting transients with full power delivery at above 91% efficiency is available. The 50Hz motors are heavier around (5.7kg/kW at 2000W and 7.5kg/kW at 100W, respectively) than the 250Hz motors around (1.2kg/kW, 3kg/kW) but the latter require inverter control.