Hierarchical and multi-level demand response program considering flexibility of loads

Demand response (DR) has a key role in reducing the peak load and avoiding the construction of unnecessary power plants. In this study, the new modified framework is presented to plan and control DR programmes (DRPs) with a novel mathematical model. The proposed hierarchical DRP is designed at three time levels to flatten the load curve, to balance between supply and demand, and to support system frequency. The proposed structure consists of three control loops with different response times from a fraction of a second to several hours for scheduling DR via defined control parameters in this programme. To minimise load variations and customer cost, the novel objective function based on weight matrices is presented. To optimally transfer loads, these matrices are weighted based on power market prices, load level, and flexibility of loads. Moreover, the demand flexibility index is used to take into account the uncertainty in the predicted load pattern and reduce errors of aggregation demand. The proposed programme has been implemented on a 20-kV feeder to indicate its effective performance compared to hopping DR and centralised direct load control (DLC). The proposed mathematical model is verified by numerical results.