A coordinated control scheme for VSC-MTDC system with multiple renewable energy sites based on voltage margin and adaptive drooping control

Abstract

This paper designs a novel coordinated control scheme to improve the control performance of voltage source converters (VSC) based multi-terminal high voltage direct current (MTDC) transmission network by merging the benefits of adaptive drooping and voltage margin controllers. In this proposed scheme, the droop coefficient is used to manage the deviation of DC voltage and maintain power sharing by shifting the control modes of the rectifiers and inverters in the presence of considerable power disturbances. The droop coefficient is planned based on the stability limit of DC voltage. The performance of the designed control scheme is compared to that of existing coordinated control and voltage margin droop control approaches. A ± 400 kV five-terminal VSC-MTDC test network is developed in PSCAD to verify the planned control method. The simulation results indicate that the proposed coordinated control scheme can achieve good performance for controlling the DC voltage and maintaining active power in the MTDC system under the voltage margin control acts as an inverter, the main converter is out of service, the converter outage with inverting VSC, and the short circuit fault at the converter terminal operating scenarios.