Abstract
History review of stability investigation of refrigeration systems is given in this paper and three research phases are divided, i.e., oscillatory motion of the mixture -vapor transition point in evaporation process, stability of the evaporator and thermal expansion valve control loop and stability of the refrigeration system with a fixed displacement compressor. Then the stability of automotive air conditioner with a variable displacement compressor is discussed preliminarily and is a new problem and different from the fixed capacity refrigeration system. The stability of automotive air conditioner with a variable displacement compressor is classified as two kinds of stability problems, i.e., perturbation stability and great disturbance stability in this paper.