Tuning Method of Node Emergency Support Power Demand Based on Transient Frequency Target Trajectory

The decreasing rotational inertia in new Power Systems exacerbates the issue of frequency stability. When the system experiences a large active power deficit, it is necessary to quickly tune the support power demand of the nodes involved in frequency emergency control to ensure that the transient frequency drop trajectory remains above the target. To address this, this paper proposes a method for tuning the emergency support power demand of nodes based on the control of the transient frequency target trajectory. First, under the premise of meeting inertia indicators of the system frequency stability criteria, an optimal target state is established where the initial transient frequency drop trajectory in any power deficit scenario should remain relatively stable. This target state serves as a benchmark to evaluate the performance of the actual frequency drop at each monitoring node. Second, data is collected based on the short-Term frequency drop trajectory at the initial stage of disturbance. The trajectory data is used to assess the difference in equivalent inertia time constants according to its deviation from the target. This difference is then converted into the emergency support power demand for each node, thereby providing significant reference for further allocation of frequency precise control.