Power Source Flexibility Margin Quantification Method for Multi-Energy Power Systems Based on Blind Number Theory

The grid connection of a high proportion of renewable energy generation increases the uncertainty in power systems. Therefore, the flexibility margin of different energy sources needs to be quantified to cope with the uncertainty change and maintain the dynamic balance of power system flexibility. In this paper, first, the flexibility characteristics of source, net, load and power and load community (PLC) are analyzed. The dynamic equilibrium relationship among them is briefly introduced. Secondly, taking into full consideration the complex output characteristics of different energy sources and combining their respective flexibility characteristics, a quantitative model of the power source flexibility margin for thermal power, hydro-power, gas power and concentrating solar power is established. A quantitative model for a power source flexibility margin in PV and wind power based on blind number theory is established. Furthermore, the calculation method of theoretical power generation capacity, which can reflect different characteristics of output power of various energy sources, is presented. The actual output power of each power source in each period is predicted. Finally, a case study shows that the model and method can consider the operating characteristics of different types of power sources, and quickly and accurately quantify the adjustable range of flexibility margins of each power source at different periods of time, which can provide an important basis for evaluating the capacity of renewable energy consumption and the optimal operation of multi-energy power systems (MEPSs).