A Novel Decoupled Interconnecting Method for Current-Source Converter-Based Offshore Wind Farms

This paper presents a novel interconnecting approach for the permanent-magnet synchronous generator-based offshore wind farm, where cascaded pulsewidth modulated (PWM) current-source converters (CSCs) are employed on both generator- and grid-side. The total numbers of cascaded PWM CSCs for the onshore grid connection are equal to the number of wind generators installed in the wind farm. The proposed interconnecting method enables simple configuration without the need for a bulky and costly offshore converter substation. Furthermore, a new decoupled control scheme for the independent active and reactive power control with variable dc-link current regulation is developed for the grid-side converters. The key feature of the control scheme is that the minimized dc-link current control is achieved without the use of a long-distance communication link. Both simulation and experimental results are provided to verify the effectiveness of the proposed control scheme.