AGC Command Allocation Coordinating Frequency Performance and Anti-Vibration of Hydropower Units

Abstract

Hydropower units (HPUs) are inevitably affected by vibration zone when participating in frequency regulation through automatic generation control (AGC). To improve this., the anti-vibration demand of HPUs is embedded into the AGC command allocation in existing studies. However., the system frequency regulation demand is ignored when considering the anti-vibration demand., which may deteriorate the frequency performance. With this in mind., an AGC command allocation method coordinating frequency performance and anti-vibration of HPUs is proposed in this paper. Firstly., the adjustment amount for crossing the vibration zone and the available regulation capacity considering the anti-vibration of HPUs are evaluated. Then, an optimal selection strategy considering the system frequency regulation demand is proposed to determine the HPUs that implement the vibration zone crossing. Correspondingly, the aforementioned evaluation results are adjusted. Finally, the AGC command is allocated to HPUs and thermal power units (TPUs) with the comprehensive consideration of system frequency regulation demand, anti-vibration demand of HPUs, and available regulation capacity of HPUs and TPUs. Time-domain simulation results based on practical data demonstrate that the proposed method can reduce the impact of the vibration zone on HPUs while ensuring the system frequency performance.