Hierarchical Power Tracking of Rail Gravity-Energy Storage with Periodic and Batch-Arrival Triggers

Short-timescale power tracking in transportation rail gravity-energy storage (TRGES) involves continuous speed regulation and discrete changes in active-carrier configurations. This study develops a hierarchical coordination framework linking carrier-batch motion, station-arrival events, and dynamic grid power. A bidirectional power model accounts for gravitational power, running resistance, conversion losses, and translational inertial power. The controller first evaluates speed regulation under the current configuration and then searches additional carrier–payload configurations in ascending order of carrier-pair count. At the first feasible count, candidates are compared by transition duration and target-state loss power. Smooth speed trajectories coordinate state transitions with grid-power, acceleration, adhesion, and equipment constraints. Periodic command updates and actual batch arrivals initiate decisions on a common event timeline. Two author-designed one-hour command sequences evaluate energy release and energy storage under prepared, speed-matched batch entry. The root-mean-square tracking errors are 1.3819 and 1.1749 MW, respectively. Compared with periodic-only control using a 10 s decision interval, the proposed method reduces these errors by 27.06% and 42.01%, while requiring fewer decision executions. These results demonstrate the tracking benefit of coordinating batch-state updates with inertia-aware speed planning under the evaluated operating assumptions.