Using Virtual Synchronous Generator Control Based Energy Storage to Enhance the Stability of Sending Terminal in LCC-HVDC System

This paper uses the virtual synchronous generator (VSG) control based energy storage to enhance the stability of sending terminal in line line-commutated converter (LLC) based high voltage direct current (HVDC) transmission systems. LCC-HVDC are widely utilized in China to transmit renewable power generation from western area to the east in thousands kilometers distance. However, the reports of stability about HVDC and renewable power generation occur in recent decades. Based on the impedance theory, this paper analyzes the small signal stability of HVDC sending terminal. Recently, because of flexibility and functionality of supporting grid, power electronics based energy storage is attracting a wide-spread attention. The impedance model of virtual synchronous generator control (VSG) based energy storage is introduced in this manuscript. The impedance analysis indicates that the VSG based energy storage can improve the stability of HVDC sending terminal. Based on the impedance model, the capacity of energy storage is also analyzed. To illustrate the correctness and effectiveness of impedance analysis, the simulation results are given in the manuscript.