Research on UHVDC Transmission Capacity Improvement under the Background of Carbon Neutral

Under the background of “carbon neutralization, carbon peak”, power generation enterprises vigorously develop clean energy, and some UHVDC supporting thermal power units are replaced by new energy units. Considering that all thermal power plants under construction are put into operation, and the subsequent thermal power plants can not be put into operation as planned, combined with the current limited factors of UHVDC capacity, this paper proposes a scheme from two aspects of controlling the transient overvoltage level and ensuring the collection of DC power, so as to improve the UHVDC transmission capacity. The research shows that the scheme of installing a condenser in the converter station is recommended, which can improve the DC transmission capacity to full power operation, and has no impact on the supply and demand situation in the province and the grid structure at the sending end. “New energy + energy storage + distributed condenser” is recommended to meet the demand of DC power. This study provides an important reference for large-scale new energy units connected to UHVDC System.