Adaptability Research and Practice on Phasing Operation of Hydropower Units in New Energy Intensive DC Near-area

In order to improve the voltage support capability of the line commutated converter high voltage direct current (LCC-HVDC) transmission system, this paper proposes to transform hydropower units into phasing operation in new energy-intensive DC near-area, which can not only provide more voltage regulation capability, but also increase the utilization efficiency of hydropower units under the limited condition to save the investment of synchronous condensers. Firstly, the theoretical basis of the phasing operation of hydropower units is analyzed. Then, based on the PSASP simulation of a typical new energy-intensive DC transmission grid in western China, an adaptability analysis is presented, including the sensitivity to overvoltage suppression and the capacity substitution of synchronous condensers. Finally, a work plan for the transformation of hydropower units is proposed to provide technical support for practical work.