Abstract
To achieve high efficiency of scroll compressors in wide capacity range, a pulse width modulation(PWM) bypass capacity control system for air conditioners has been developed and the fundamental characteristics of the system was investigated in this study. Pressures and power inputs were measured to clarify the dynamic characteristics. Then the PWM period was determined by means of a numerical simulation, where calculated pressures were in good agreement with these of the measurement. Using this period, the performance tests of the compressor with PWM bypass capacity control were carried out. In the results, the capacity reached 30% of the load corresponding to the lower limit of rotational speed, and the calculated efficiencies were shown to agree well with these of the experiments.
