Photovoltaic array driven adjustable speed heat pump and power system scheme for a lunar based habitat

A high reliability power system scheme, incorporating a photovoltaic power supply and adjustable speed heat pump for life support is presented in this paper. Initial design guidelines and also a description of the state of technology available is presented herein. The power supply scheme will be used as input to an adjustable speed drive (ASD) which will drive a heat pump. A brief study of various aspects of ASDs is presented; further a summary of the relative merits of different ASD systems presently in vogue is discussed. The advantages of using microcomputer based ASDs is widely understood and accepted. Of the three most popular drive systems, namely the induction motor drive, switched reluctance motor drive and brushless DC motor drive, any one may be chosen. The choice would depend on the nature of the application and its requirements. The suitability of the above mentioned drive systems and control techniques for photovoltaic array driven ASD for an aerospace application are discussed. Also discussed are several possible power system designs for a potential lunar habitat.