LFAC-transmission systems for remote wind farms using a three-phase, six-pulse cycloconverter

摘要

This paper presents an alternative transmission system for remote wind farms to main grids using a low-frequency AC (LFAC) technology and a robust-modeling method for analysis of the alternative-transmission systems. The LFAC transmission system uses a lower frequency (20Hz/16.666Hz) than nominal frequency (60Hz/50Hz) of main grids by introducing a three-phase six-pulse cycloconverter. The benefits of the LFAC transmission system are demonstrated as follows: reduced-investment cost compared with HVDC-transmission systems and increased power transfer capability as compared with 60Hz-HVAC transmission systems. In this paper, the economical and technical benefits of LFAC transmission systems are presented, the modeling method using the quadratic-integration method is presented, and the superior properties of the quadratic integration are demonstrated with an example LFAC-transmission system.