Research on the Coordinated Control of the True Bipolar VSC-HVdc Grid Based on Operating Point Optimization

The voltage source converter based high voltage direct current transmission system with the true bipolar wiring mode features higher flexibility and reliability, yet it cannot be without a proper and effective coordinated control strategy, which is the key to the safe and reliable operation of the system as well as the effective and full utilization of renewable energy on a large scale. A step further from the conventional droop control strategy, the coordinated control strategy based on operating point optimization is proposed in this paper. This paper first illustrates and examines the coordinated control method at the system level in view of special wiring and control modes; it then looks into the method of operating point optimization seeking to achieve both safe and cost-effective operation; and the paper finally demonstrates the effectiveness of the coordinated control strategy verified by MATLAB and PSCAD simulations from the perspective of system operating point deviation, security, and cost-effectiveness.