Transient Stability Constrained Optimal Power Flow in MixedAC/Multi-Terminal VSC HVDCSystem

This paper proposes a hierarchical transient stability constrained optimal power flow (TSCOPF) analysis in a power system with a multi-terminal voltage-source converter (VSC) high-voltage direct current (HVDC) system and large-scale wind farms. This aims at determining the reinforcement and operation of the power system using the multi-terminal VSC HVDC (MTDC) system. By the method, the wind farms can be installed without any transient instability issues. On the AC grid side, transient rotor-angle stability and transient AC voltage stability are included as additional constraints. On top of that, the constraints of DC bus voltage fluctuations and DC transmission line current deviations on the DC grid side are also taken into account. Time-domain simulation approach is applied to investigate these transient stability constraints. The MTDC system reinforcement is designed considering wind power transmission and economic operation of the system model. The influences of the transient stability constraints on the system operation costs with high and low wind power output patterns are discussed. (c) 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.