Adaptive digital MPPT control for photovoltaic applications

Maximum Power Point Tracker (MPPT) is often used to increase the energy conversion efficiency for intermittent energy sources. Numerous of research teams work today to improve this type of algorithms. We had developed real-time MPPT controls based on the Extremum Seeking Control principle first implemented on analogical circuit. Today, to be more flexible and adaptive with several structures of power static converters, our new MPPT algorithms are implemented on numerical circuits. Our aim is to obtain high performances. To achieve a high quality matching between sources and loads, our new MPPT control adjusts continually the static converter duty cycle. Transitory effects are immediately detected and new MPP rapidly recovered. In addition, this digital control has an adjustment delay which allows an adaptation to a large power range from high to low points and then a real optimisation. Experimental results validate the global behaviour of this control for photovoltaic systems.