Design of a Switching Circuit to Improve Output Power of SPV Modules during Partial Shading

Abstract

The presence of bypass diodes with SPV modules typically shows multi peaks in P-V and I-V characteristics in partial shading conditions. Normal maximum power point tracking techniques are not able to track the global peak. The mismatch in voltages of PV modules results in reduction of maximum extractable power even when complex MPPTs such as PSO, ant colony, cuckoo are successfully find global peak. This paper presents a simple circuit using an inductor and single power electronic switch for improving the output power reduced in PV modules under partial shading. The effectiveness of the topology proposed is investigated and confirmed for series connected partially shaded PV modules. The idea is to take the current from the unshaded modules or modules with higher irradiations, divert and process  it using a circuit having single power electronic switch, an inductor and power diode so as to aids the total output current and consequently the output power. Simulation results illustrate the enhancement of output power, specifically under severe partial shading conditions.