BACKSTEPPING CONTROL OF CUK CONVERTERS FOR SOLAR PV and BATTERY ENERGY STORAGE SYSTEMS

摘要

There is a continuing trend of increasing deployment of solar photovoltaic sources for providing energy to the bulk electricity system. This increases the need for reliable converters in order to interface low voltage dc sources to medium and high voltage ac systems. One of the challenges in controlling dc-dc converter is maintaining good output voltage regulation while supplying constant power loads. This paper considers a recursive backstepping design methodology and Lyapunov theory to control dc-to-dc switched mode Cuk converter. Conventional feedback methods such as proportional-integral controllers require a linear model in order to design the controller parameters. However, the nonlinear effects associated with switched mode power converters usually require that performance levels be reduced in order to assure acceptable stability levels. As an alternative, backstepping design methods offer improved performance in terms of reduced settling time and minimized tracking errors. The design process for backstepping control techniques is described in the paper for dc-dc converters with battery and solar PV array connections. Detailed simulation results indicate the benefits of this design method under a wide range of possible operating conditions.