Design and implementation of a solar power optimizer for module level power electronics application

Partial shading on series-connected photovoltaic (PV) panels in conventional PV systems results in lower harvested power. To resolve this, it is vital to utilize module level power electronics (MLPE) such as Solar Power Optimizers (SPOs). This paper introduced a non-isolated common ground non-inverting output voltage buck-boost converter as an SPO. Proposed converter benefits from continuous input and output currents which has a significant role in designing SPOs. Having a quadratic gain, beside acceptable step-down range are other features of the converter. Operating principle, design, steady-state, small-signal analysis, and dynamic performance of proposed converter are included. Proposed converter is compared with other buck-boost converters in terms of voltage gain, voltage stresses, continuous input and output current, and output polarity. To validate the performance of introduced converter, experimental results for a prototype with input voltage 24 V, output voltage 72 V for step-up and 15 V for step-down modes are given and results are examined. The maximum efficiency of the prototype is 93% and 89% for step-up and step-down modes, respectively. To evaluate the effect of proposed SPO for extracting maximum available power from PVs, simulation results of a grid connected PV system with two series connected SPOs is discussed. This paper introduces a non-isolated common ground non-inverting output voltage buck-boost converter as a solar power optimizer, which offers a extended conversion ratio and maintains continuous input and output currents. This converter is well-suited for renewable energy applications and reduces the size of input and output filters. Having a semi-quadratic gain, beside acceptable step-down range makes this converter suitable for solar power optimizer application. Both switches in the proposed converter are driven with simultaneous gate signals, simplifying control mechanism. image