A robust maximum power point tracker with fully analog implementation

Abstract

An analog circuit for maximum power point tracking of a PV battery charger with minimum number of elements is proposed which works in a full range condition with a fixed switching frequency. In conventional MPPT algorithms which provide PV current or voltage reference value as output, fast climate changes may cause system instability. Here, a new variable is defined to eliminate the problem and improve the stability of the system. In order to compare the presented circuit with a conventional system, perturb and observe (P&O) MPPT algorithm which is well-known in PV systems is implemented on the same system. Simulation results (Conventional P&O algorithm and proposed structure) are presented and compared which demonstrate performance and effectiveness of the proposed analog MPPT circuit. An experimental set up has been made which the results match with theory and simulation.