A Single Stage CCM Micro Inverter for Solar Photovoltaic AC Module fed BLDC Applications

Abstract

BRUSHLESS dc (BLDC) motors have become increasingly popular in the past decade due to the advantages such as high efficiency, high power density, compact size, high ruggedness, low maintenance requirements, and their immunity to electromagnetic interference (EMI) problems. In this theory dual-stage micro-inverters are commonly used in grid-connected photovoltaic (PV) systems. The high boost DC/DC converter is necessary for the grid-connected micro-inverter because the input voltage from a single solar panel is very small. A DC/DC Zeta converter with coupled inductor which operates at moderate duty ratios is proposed. This topology is basically derived from a conventional Zeta converter by replacing the input inductor by a coupled inductor. The turn’s ratio of the coupled inductor increases the voltage gain and the secondary winding of the coupled inductor is in series with a switched capacitor for further increasing the voltage. High voltage gain is achieved by employing high turn’s ratio to coupled inductor. The leakage-inductor energy of the coupled inductor is efficiently recycled to the load by additional capacitors and diodes and thus efficient energy-conversion is possible. The stress on the active switch is also restrained. The proposed Zeta converter with coupled inductor topology and BLDC is simulated and the results are obtained.