Design of a Linear Motor: An Optimization Approach Considering Motor and Inverter Losses with Different Voltage Waveforms

This paper presents the design and testing of a brushless permanent magnet linear motor to be used in a compressor application. Usually in the literature, optimization process focuses in the motor or the inverter optimization. However, voltage waveform generated by the inverter has direct influences in the motor and inverter losses. Here it was used a methodology that optimizes the motor taking into account motor and inverter losses models. In this sense, the process optimizes the efficiency of the motor and inverter set, resulting in a global optimum scenario. A two-step optimization process using a 3D analytical MEC routine and a 3D Finite Element software was used to simulate the linear motor. The optimization was carried out with two supply voltage waveforms. The first is the single pulse voltage and the second is the sinusoidal PWM waveform. The designed motor was assembled and tested in a dynamometer to evaluate the motor, inverter and set efficiency, supplied with both waveforms of voltage.