Virtual synchronous generator based pole control in high-voltage DC transmission systems

Abstract

The use of renewable energy to realize decarbonization is rapidly increasing, and considerable research is being performed to achieve highly efficient high-voltage direct current (HVDC) transmission for offshore wind power generation over long distances. However, in the case of onshore AC power transmission and distribution systems, with the mass introduction of distributed energy resources (DERs), voltage and frequency fluctuations often occur. It is thus necessary to implement the control function of smart inverters, which can facilitate the stabilization of the AC system, in the grid-connected inverters of DERs. Virtual synchronous generator (VSG) control is a smart inverter control strategy that can contribute to the stability of the AC system. In this study, conventional power control and VSG control were applied to the control strategy of modular multi-level converter-based poles of the HVDC transmission system, and the AC system fault tolerances of the entire system were examined.

Keywords

• Fault tolerance
• High-voltage direct current transmission
• Modular multilevel converter
• Short circuit ratio
• Virtual synchronous generator