兼顾超低频振荡抑制和调频性能的自动发电控制参数优化

Parameter Optimization of Automatic Generation Control(AGC)System Considering Ultra-low Frequency Oscillation Suppression and the Secondary Frequency Regulation Performance

直流异步联网工程投运后,高水电占比送端电网已多次出现由于自动发电控制(automatic generation control,AGC)环节不稳定导致的频率振荡现象。针对该问题,提出了兼顾AGC模式超低频振荡抑制和调频性能的AGC控制参数优化方法。首先建立了高水电占比送端电网的负荷频率控制模型,并基于该模型分析了AGC控制参数与系统频率稳定之间的相互影响关系。在此基础上,定义特征阻尼系数(characteristic damping index,CDI)作为AGC环节阻尼性能指标,建立综合优化目标函数,并采用粒子群优化算法进行求解。最后,对优化结果进行了仿真验证,仿真结果表明,采用本文方法能够在保证AGC调频性能的同时有效提高AGC控制系统的阻尼水平,抑制AGC模式超低频振荡。

After the operation of asynchronous interconnection,the sending power system with high-proportion hydropower and multiple DC line delivery has occurred ultra-low frequency oscillation repeatedly thanks to small disturbance instability of AGC system,which threatens the safety of power grids.According to the principles of AGC,the load frequency control model was established for the sending power grid with high-proportion hydropower firstly.The effect of AGC parameters on small disturbance stability was analyzed.Furthermore,characteristic damping index was defined as AGC damping performance index and comprehensive objective function was established.The research adopts particle swarm optimization(PSO)algorithm to set PI controller’s parameters.Finally,the simulation results show that the proposed method not only ensures AGC’s frequency modulation performance,but also reduces negative damping greatly provided by AGC to power grid,which is beneficial to restrain ultra-low frequency oscillation caused by AGC.