Composite system spinning reserve assessment in interconnected systems

Deterministic methods to evaluate unit commitment and spinning reserve requirements cannot explicitly recognise the stochastic nature of a power system. Probabilistic techniques can, however, be used to incorporate a wide range of stochastic system parameters. The usual techniques of probabilistic unit commitment in an interconnected power system consider the tie-line constraints but not the transmission facilities within the systems. In a real power system, the transmission facilities within the systems have limits and do fail. Units committed from only probabilistic generation studies, therefore, provide optimistic values. In the paper, the usual techniques of unit commitment are extended to calculate a risk value from a composite system point of view. The effect on the risk value of rapid start and hot reserve units are considered.