Performance Testing of an Active Multiport DC Link for Grid-Connected PMG-Based WECSs

This paper presents the development, implementation, and performance evaluation of a new active dc link for permanent magnet generator (PMG)-based wind energy conversion systems (WECSs). The proposed dc link is developed based on the multiport converter (MPC) topology with two dc-dc power electronic converters (PECs) that have separate inputs and parallel-connected outputs. The first dc-dc PEC is designed as a boost converter, while the second dc-dc PEC is designed as a flyback converter. Each dc-dc PEC is operated and controlled independently to facilitate processing continuous and/or discontinuous input dc voltages. The performance of the MPC active dc-link is experimentally evaluated using a grid-connected 7.5-kW PMG-based WECS, when operated under different wind speeds and/or levels of power delivery to the host grid. Test results show that the proposed dc link can produce a high-quality-regulated dc output voltage over a wide range of wind speeds and levels of power delivery to the host grid. Performance results also demonstrate that the operation of the MPC active dc link has minor impacts on the operation and control of the generator-side and grid-side PECs.