Chapter 22 - The sector coupled flexibility resources

Abstract

The research work by China-based scholars to date has established a number of renewable energy models and proposed an array of power system flexibility indicators based on reliability and equipment regulation capability. However, the renewable energy models and the traditional power supply models are not known to be highly compatible, and the indicators are not supported by a quantitative relationship with the level of renewable energy accommodation and system security, with no clear mechanism in sight for boosting renewable energy accommodation via complementarity. These accentuate the dire need for establishing a more sophisticated unified model for multiple heterogeneous energy sources and a multienergy power system flexibility evaluation system. Firstly, power aggregation techniques for multiple power sources and characterization models for postaggregation integrated regulatory flexibility are proposed. Then, on this basis, the concept of flexibility supply-demand curve, which characterizes comprehensive load balancing capability, is proposed in the energy-time coordinate system. The multitimescale flexibility adequacy criterion of the system and the optimal allocation method of multitimescale flexibility resources are proposed. The accuracy of the model is verified by the IEEE standard example and the Xinjiang long-term power grid example. Finally, a two-stage homogeneous dispatch model of the power system is established. The first stage is a point forecasting day-ahead output scenario, and the second stage focuses on multiple possible real-time power generation scenarios. The system results of practical examples in Qinghai and Xinjiang show that the proposed model can fully explore the flexibility of various resources in the system, thereby enhancing the system’s new energy consumption capacity and reducing its operating costs.