Design and implementation of flyback MPPT converter for PV-applications

One of major problems related with PV-applications is common mode currents. The issue can be solved in two ways: galvanic decoupling of AC-grid and chopping the common mode currents by additional actively controlled circuitry. Flyback converter is good solution for MPPT tracking for PV-modules up to 100-150 W with galvanic decoupling. The problem of designing of this type of converter is that most of design guides and literature is dedicated to consumer electronics applications. MPPT converter design have different starting points of calculations. The paper contains the suggested approaches to the calculations, design recommendations, considering the specific nature of PV-sources and NOCT model of PV-module. The approach calculations, design guidelines, recommendations and simulation of power electronics part of MPPT converter and experimental results with implemented circuit are presented and discussed. In order to increase the efficiency during tests the circuit was upgraded with active clamp. After the tests active clamp was upgraded to the forward active clamp topology. The efficiencies and key waveforms of voltages are compared and analyzed.