Real-time security assessment of power grid operation trends

Under the situations of increasing complexity of power system and more difficulty in the real-time control, it is critically needed for security to assess power grid operation trends accurately, rapidly and roundly in a short time. But it can´t meet the double requirements of round and rapid assessment through the state indicator or dck indicator. This paper focuses on online real-time operation assessment, and establishes a real-time security assessment method of power grid operation trends based on state indicator system. The proposed method includes preliminary assessment and refined calculation. Preliminary assessment combines fuzzy theory with the obtained region importance indicator calculated by load importance to determine system operation trends a fter adverse events and finds out the problem region. Refined calculation calculates the indicators of state indicator system belong to the problem region and assures the s pecifically dangerous indicator. As thus, the double requirements of round and rapid assessments could be met. An example is given to prove validity and feasibility of the proposed method.