NEW I-V PHOTOVOLTAIC CURVES TRACER BASED ON DC-DC CONVERTERS WITH COUPLED-INDUCTORS

摘要

The achievement of I-V and P-V curves of photovoltaic panels gives the possibility to obtain the exact operation point, the short-circuit current (I{sub}(sc)), the open-circuit voltage (V{sub}(oc)), the maximum power point (MPP) and the Fill Factor (FF). These are significant parameters for the design and for the start-up of a photovoltaic installation. In this paper, we propose and analyse by means of simulation two topologies of DC-DC converters candidates to implement I-V and P-V curves tracers of photovoltaic modules. This capacity must that mainly as much structure SEPIC (Single-Ended Primary Inductance Converter) as the Cuk they present a relation of conversion buck-boost. Thanks to this property, a complete sweep of the voltage and the current given by a photovoltaic panel can be made, including V{sub}(oc) and I{sub}(sc). Both structures allow in addition, the incorporation of magnetic coupling between his inductors. These structures are implemented by coupled inductors and present two fundamental advantages: (1) they allow to emulate a resistance at the input converter within the range [0, ∞] and (2) they guarantee a null ripple in the input current when the magnetic coupling of its two inductors fulfils ZRC (Zero Ripple Condition).