High efficiency standalone photovoltaic system using adaptive switching of an interleaved boost converter

Photovoltaic generation is gaining increased importance as a power source in many applications. However, energy conversion efficiency is an important factor for the long term feasibility of these systems. Significant work has been carried out into improving the effectiveness of solar arrays in the last 20 years. In addition, there has been substantial research into novel power converter topologies for maximum energy efficiency. However, in photovoltaic applications, even the most promising power converter topologies do not necessarily guarantee optimum performance under all operating conditions. For example, the efficiency of the power conversion stage may be excellent during periods of high irradiance, but significantly lower in poorer light conditions. This work attempts to address this problem, by seeking to achieve higher energy conversion efficiency under sub- optimal conditions. In this paper, stand-alone photovoltaic systems using dc-dc converters are considered. A novel adaptive control scheme is proposed to maximise system efficiency over a wider range of real-time operating conditions.