Frequency-Based Dispatch of Balancing Services

In practice, power system operators do not carry out the mathematical optimisation required for optimal dispatch over very short timeframes. Instead, the very-short-term response of the power system to contingencies occurs through various automatic and heuristic (but not fully efficient) processes. Chapter 12 opens with a discussion of how dispatch occurs on the timeframe between runs of the efficient market process. Many power systems dispatch resources in the short run based on frequency deviations alone. This limits their ability to respond to network contingencies, so the network must be operated as though the next-most significant network contingency has already happened. The chapter discusses the implications of this observation for the set of feasible injections and the average utilisation of the network. The chapter concludes with a discussion of the efficient procurement of balancing services.