Frequency controlled system design to improve energy consumption of compressor motors used in refrigerators

The objective of this thesis is to investigate the energy performance of the refrigeration system when compressors has single-phase asynchronous motor which is controlled with variable speed controller. If we consider household electricity consumption, refrigerators are at the top of the list. In this study, single-phase asynchronous motor structures, types of speed control methods, frequency control methods, inverter topologies and modulation methods are investigated. After that, a domestic refrigerator compressor and a compatible drive system are determined. Based on catalog values of the selected compressor, a compressor model is created with the help of the predefined motor model. Simulation of the generated model is verified that it is compatible with the real compressor. In the drive system, as a control method, scalar control (V / f speed control), for the inverter topology single-phase full bridge inverter and for the modulation method, unipolar sinusoidal pulse width modulation are used. Total harmonic distortion and energy consumption are measured in the generated simulation. The measured consumption values are compared with the energy consumption values of the conventional and variable-speed cooling systems which are available in the market.