Analysis of the Influence of the Stability Factors of PV/T-SAHP on the Performance of the System

The integrated photovoltaic/thermal collector (PV/T) with solar assisted heat pump (SAHP) often operates under an undesigned condition. Against the backdrop of heat pump system oscillation resulting from the mismatching between collectors area and compressor capacity, this work explores the dynamic performance of heat pump system at a fixed compressor frequency when the condensing water temperature and electronic expansion valve (EEV) opening are variable or invariable. We also consider why the system is unstable and propose the theory of SAHP system stability. Also, a preliminary performance analysis is made on SAHP system that is respectively influenced by an inverter compressor and EEV. The MSS(Minimum Stable Signal) line theory is proposed to account for system unstabilty in the research of the match between EEV and evaporators, that is to say, the critical problem of keep the system stability is to find out how evaporators superheat under the circumstance of specified loads and its corresponding EEV opening, in other words, to find the MSS line.