Analysis of Partial-Power Processing Converters for Small Wind Turbines Systems

In order to connect small wind turbines (SWT) systems in the single-phase grid, three-stages configurations (rectifier, dc-dc converter and inverter) have been suitable due to the power decoupling between the inverter dc-bus and the rectifier output, adding facility to realize the maximum power point tracking. However, the losses of the system are increased due to the additional dc-dc converter. To reduce this effect, partial-power converters (PPCs), in which only a part of the power generated by the SWT system is processed by the converter, can be used. In this method, the characteristics of topology (boost or buck), power and voltage levels, and the operating range can impact in the amount of active power handled by the converter. Since the analysis of PPC applied to wind systems remains to be investigated in the literature, this paper analyzes the Full-Bridge Phase Shift (FBPS) with Zero-Voltage Switching (ZVS) operating as PPC in SWT systems connected to the single-phase grid. To verify the theoretical analysis and evaluate the performance of the proposed system, simulation results are presented for a 1.5 kW SWT system, in which the FBPS PPC processed only 70% of the generated power.