双馈抽水蓄能机组参与电网调频的改进虚拟惯性控制策略

为了提高双馈抽水蓄能机组参与电网调频的能力,提出一种带比例—微分(PD)环节的双馈抽水蓄能机组改进虚拟惯性控制策略。首先,基于双馈抽水蓄能机组运行特点,分别建立了可逆水泵水轮机和双馈感应电机的数学模型及双馈抽水蓄能机组控制模型。其次,根据机组虚拟转动惯量与转速调节及电网频率变化的关系,提出一种带PD环节的双馈抽水蓄能机组改进虚拟惯性控制策略,并给出了改进虚拟惯性控制相关参数的整定方法。最后,通过对含双馈抽水蓄能机组的3机系统的仿真分析,验证了所述策略可有效提升双馈抽水蓄能机组在发电、电动工况下的频率响应能力,提高了电力系统的频率稳定性。

Improved Virtual Inertia Control Strategy of Doubly Fed Pumped Storage Unit for Power Network Frequency Modulation

Aiming at enhancing the capability of the network frequency modulation supported by the doubly fed pumped storage unit(DFPSU), a kind of improved proportional-differential(PD)loop virtual inertia control strategy of DFPSU is proposed. First, based on the operation characteristics of DFPSU, the models of reversible pump turbine, doubly fed induction machine and control system of DFPSU are established. Then, according to the relationship between the virtual inertia, the rotational speed adjustment and the network frequency variation, a kind of improved PD loop virtual inertial control strategy of DFPSU is proposed. In addition, a control parameter calculating method in the improved PD virtual inertia control is also provided. Finally, a three-machine system with DFPSU is used to validate the proposed control strategy. The simulation results show that the proposed control strategy could effectively improve the frequency response ability of DFPSU in both the generator and motor mode and the frequency stability of the power system at the same time. This work is supported by National Natural Science Foundation of China(No. 51377184)and Fundamental Research Funds for the Central Universities(No. 106112016CDJZR158802).