Hybrid Dispatching Method Considering Merit-order and Ramp-rate for Load Frequency Control

Abstract

Dispatching method according to merit-order (MO method) for load frequency control (LFC) will be applied after grid control cooperation (GCC) starts in 2020, since grid operators tend to put high priority on economic efficiency. However, MO method decreases frequency stability in comparison with conventional method according to ramp-rate (RR method) because of the shortage of the total ramp-rate. To solve this challenge, hybrid method by switching RR method and MO method according to frequency fluctuation is proposed. Evaluation results on AGC30 (Automatic Generation Control) reveal that the proposed method can reduce the fuel cost in comparison with the RR method while meeting the frequency stability criteria.