Ultra-Low Reactive Power Operation and Control Strategy of Hybrid Line Commutated Converter Based on IGCT for HVdc Application.

Existing line commutated converter (LCC)-based high-voltage dc (HVdc) systems require large reactive power during operation and reactive power compensation equipment under construction. However, the equipment is expensive and occupies a huge area. In this letter, a novel operation of hybrid line commutated converter based on integrated gate commutated thyristor (IGCT) is proposed to achieve LCC with ultra-low reactive power (LR-LCC), and the corresponding control strategy is developed by utilizing IGCT's active blocking and bidirectional voltage withstanding capability. It can almost eliminate the system's extinguishing angle (?), and the power factor is close to 1. This novel LR-LCC can result in advantages, including a much lower manufacturing cost and volume of reactive power compensation equipment for HVdc application.