A Full-Bridge Partial-Power Processing Converter for Three-Stage Small Wind Turbine Systems

Abstract

In order to process the energy generated by small wind turbines (SWT) in grid-connected systems, three-stage configurations (rectifier, dc-dc converter, and inverter) have been suitable due to low cost of three-phase diode rectifiers, facility to perform the maximum power point tracking in dc-dc converters, and power decoupling between the grid and wind generator. As drawback, the three-stage solutions can present higher losses in relation to two-stage systems due to the additional converter. To reach a better efficiency, partial-power converters (PPC) can be used, in which only a part of the power generated by the SWT is processed by the converter. In this method, topology, power/voltage levels, and the operating range characteristics can impact the power handled by the converter. Since the experimental analysis of PPC applied to SWT systems remains to be investigated in the literature, this paper analyzes the Full-Bridge with Zero-Voltage Switching operating as PPC in SWT systems connected to the single-phase grid. In order to evaluate the performance of the proposed structure, experimental results are verified for a 1.5 kW SWT, in which the FullBridge PPC processes only 70% of the generated power. In relation to the full-power processing, the partial-power processing has reduced the losses in 35.9%.

Keywords

• Full-Bridge
• Grid-Connected
• Partial-Power Processing Converters
• Small Wind Turbines