Analysis and control for linear compressor system driven by PWM inverter

Recently, the linear compressors with the free piston driven by the linear motor have widely attention in the cooling apparatus such as a refrigerator due to high efficiency. The method of using triacs as a linear motor drive is not satisfactory to improve the efficiency of the linear compressor. In this paper, the performance of the linear compressor using a PWM inverter such as the efficiency and power factor are investigated with the variations of both mechanical resonant frequency and electrical resonant frequency. Through simulation and experimental studies, the performance of both the stroke and angle controls for improving the efficiency of the linear compressor is verified.