A nonlinear emergency control strategy for HVDC transmission systems

Abstract A novel nonlinear emergency control method for HVDC transmission systems is presented in this paper. First, an observation-decoupled state space model of AC and DC interconnected power systems, which allows estimation or computation of the state components from local measurements, is developed. Secondly, the nonlinear control rules of HVDC links are derived using optimal-variable-aim strategy, which not only improves the first-swing stability, but also effectively damps the subsequent power oscillation. Finally, the simulation results of a three-machine six-bus system show that the proposed method can enough use the capabilities of fast response and short-time overload of HVDC links to improve the transient stability of power systems.

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