A High-Voltage Direct Current Transmission System Using a 12-Pulse Thyristor Inverter without AC Grids' Low-Order Harmonic Distortions

摘要

This paper presents a high-voltage direct current (HVDC) transmission system using a 12-pulse thyristor inverter without AC grids' low-order harmonic distortions. Although it is effective to adopt a line-commutated converter (LCC) HVDC transmission system for connecting offshore wind farms, it generates unwanted harmonic distortions. We have proposed a novel harmonics elimination method using a three-winding transformer for LCC-HVDC transmission system with a 6-pulse thyristor inverter. This method has been confirmed to be effective with theoretical and experimental investigations. In this paper, application of the proposed method to the HVDC transmission system with a 12-pulse thyristor inverter is investigated. Strategy for the method is discussed and instantaneous waveforms of the system with the newlyproposed method are simulated. Finally, experimental investigations are carried out to confirm the validity of the strategy for the harmonics elimination method. It is shown that the proposed method is useful for the HVDC transmission system.