Study on multi-time scale frequency hierarchical control method and dynamic response characteristics of the generation-grid-load-storage type integrated system under double-side randomization conditions

Under the background of renewable energy infiltration, the generation-grid-load-storage type integrated system presents the double-side randomization characteristics. The multi-time scale interactive response mechanism of multiple subsystems is complicated. The effective dynamic control method is important for the efficient and stable operation of the integrated energy system. In this paper, dynamic characteristic analysis and simulation experiment study of the integrated system under double-side randomization conditions are carried out. First, a multi-time scale dynamic response model of the integrated system coupled with millisecond level on the electrical side and kilo-second level on the thermal side is developed. Second, based on the frequency hierarchical idea, an algorithm of subsystems cooperation is proposed. It is suitable for different distributed energy systems and can be applied to both day-ahead control and intra-day control. Third, the dynamic characteristics of the integrated system under double-side randomization conditions are analyzed. Working conditions include sunny day, cloudy day and rainy conditions on the generation side and industrial load, commercial load and appliance load conditions on the load side. Finally, based on the dynamic experimental platform of the generation-grid-load-storage type integrated system designed and built by our research group, experiment studies are carried out. The results present that the frequency hierarchical control method can reduce the power purchase and abandonment rate. The average of them is reduced by 1.76%, 10.47% and 11.93% under different loads. The maximum error between experimental data and simulation data is 12.32%. The switching process of the vanadium redox flow battery charge and discharge is the main reason of errors.