Operational Probabilistic Power Flow Analysis for Hybrid AC-DC Interconnected Power Systems with High Penetration of Offshore Wind Energy

With increasing penetration of intermittent renewable energy, power systems are facing great pressures in real-time operation and control. Minutes ahead short-term static risk assessment using the probabilistic power flow (PPF) can help system operators detect potential over-limit risks in advance and take preventive measures in time. However, current probability models of renewable power outputs lack enough adaption and efficiency in operational stage, and the PPF formulation also neglects the effects of control system and tie line power exchange of large power systems. This paper establishes a systematic operational PPF scheme for hybrid AC-DC interconnected power systems with offshore wind energy integration. An adaptive probabilistic modeling and fast update method is proposed to model multiple time-varying offshore wind power outputs. Considering different responses of control systems and AC/DC tie line power exchanges, a novel hybrid PPF is proposed to reflect power flow uncertainty more robustly and accurately. The above techniques are validated on a modified IEEE 30 bus system and the whole scheme is applied to the short-term static risk assessment of a real system in Southern China. The results show that our proposed scheme can well meet online calculation requirements, and can also achieve a more realistic characterization of operational PPF.