Suppression of continuous commutation failure in LCC-HVDC transmission based on improved virtual synchronous generator control for energy storage system

Abstract

Aiming at the poor voltage response characteristics of the line-committed converter-based high voltage direct current (LCC-HVDC) transmission system after the fault of the AC system at the inverter side, this paper analyzes the relationship between the continuous commutation failure of the LCC-HVDC transmission system and the reactive power demand in detail from the perspective of the reactive power voltage of the inverter side converter. On this basis, an improved control method for the virtual synchronous generator (VSG) of the energy storage system is proposed to enhance the commutation ability of the LCC-HVDC transmission system, to suppress continuous commutation failure. Firstly, secondary frequency regulation is added to the active power frequency control of the traditional VSG to improve the stability of the system converter bus frequency. Secondly, the leading trigger angle negative feedback control is added to the traditional VSG control, so that the system has the advantages of rapid reactive power output and voltage recovery. At the same time, different control modes are selected according to the fault location and size to improve the recovery ability and robustness of the system. Finally, based on the CIGRE benchmark LCC-HVDC transmission system model, the improved method is proven to have a good suppression effect. The results can provide a reference for actual projects.

Keywords

• LCC-HVDC transmission system
• Energy storage system
• Virtual synchronous generator
• Commutation failure
• Reactive power