Nasrollah Azam Baleghy - Dept. of Electrical Engineering Khorasan Institute of High Education Mashhad, Iran
Seyed Kamal-e-ddin Mousavi Mashhadi - Faculty of Electrical Engineering Iran University of Science and technologyTehran, Iran

Growth and increasing use of home cooling systems,especially domestic refrigerators and freezers have make improved their controllers. Nowadays, frost-free refrigeratorproper alternative to the classical refrigerator that should be defrost manually. Considering the energy efficiency and effectiveperformance, designing suitable control system for such refrigerator is necessary. In present study, a new controller for temperature and relative humidity that are two important factorsin the quality preservation of products is presented. The control system consists of two separated parts: control of temperatureand control of relative humidity. Variation of temperature and relative humidity and their rates are the inputs of controller andfrequency of compressor and voltage of evaporator fan are outputs. In terms of practical issues for implementation of the fuzzy controller in the microcontroller, Multivariate nonlinear regression is used. Nonlinear dynamic model of refrigerator [1, 2] and the unknown model of user-pattern are two causes that the fuzzy logic controller is designed

Frost-free refrigerator; Fuzzy controller; Multivariate Regression