Flexibility enhancement for thermal power unit coupled with energy storage device by real-time decomposition and...

To enhance the peak shaving flexibility of the thermal power unit (TPU) in the context of renewable energy grid connection, this article designs a flexible collaborative power generation scheme that combines TPU with vanadium redox flow batteries (VRFB) for coordinated operation. Firstly, a real-time decomposition technique for automatic generation control instruction combining improved complete ensemble empirical mode decomposition with adaptive noise, permutation entropy, and transformer network is developed to address the issue of delayed response on the boiler side. The designed real-time decomposition technology provides real-time instruction for fast tracking control of the system. Secondly, considering the complex disturbances and unmodeled dynamics in the TPU-VRFBs coupled system, an error-based active disturbance rejection control strategy with second-order disturbance compensation is proposed. By introducing two-dimensional state variables to precisely reconstruct the total disturbance of the system, the response speed and accuracy can be effectively improved. The simulation results show that under two typical cases, compared with traditional PID control (relying only on TPU), the proposed strategy reduces ITAE on the electric power channel by at least 57.1 %, verifying its superior dynamic performance and robustness.