Effects of the driving voltage waveform on the performance of the Stirling-type pulse tube cryocooler driven by the moving-coil linear compressor

The effects of three typical waveforms, namely, sine, trapezoid and smeared sine, on the performance of the Stirling-type pulse tube cryocooler (SPTC) driven by the moving-coil linear compressor are analyzed and studied experimentally. The results indicate that the dynamic pressure at the inlet of the cold finger has a weak relation with the driving voltage waveform, but the latter plays an important role in affecting both the motor efficiency and the SPTC cooling performance. In the tested range, either the cooling efficiency or the motor efficiency under the smeared sine waveform is the highest, while that under the sine waveform is the lowest. Moreover, given that the input power is below 30 W, the motor efficiencies under both smeared sine and trapezoid waveforms exceed 90%, which suggests a promising approach to achieve a linear compressor with a very high motor efficiency by optimizing the voltage waveform.