基于功频下垂控制的并网型储能系统惯量与阻尼特性分析

基于功频下垂控制的并网型储能系统可有效解决分布式电源大规模接入导致的电网频率稳定性降低的问题,同时等效提高电力系统的惯量水平与阻尼能力。以基于功频下垂控制的并网型储能系统为研究对象,通过建立其直流电压时间尺度的动态模型,利用静止同步发电机模型分析了影响储能系统惯性水平、阻尼效应和同步能力的主要参数及其影响规律。研究结果表明:下垂控制环节和功率控制环节是储能系统惯性效应与阻尼效应的主要来源,通过下垂系数和功率环PI参数的优化设计即可等效改变系统的惯性/阻尼特性。仿真实验的结果证明了研究结论的正确性,研究结论将有益于设计有效的储能系统控制策略,以辅助提升电网的惯性水平和阻尼能力,增强分布式发电系统及其接入电网的稳定运行能力。

Analysis of Inertia and Damping Characteristics for Grid-tied Energy Storage System Based on Power Frequency Droop Control

Based on power frequency droop control, a grid-tied energy storage system(GESS) can effectively impro-ve the frequency stability of power system at a high penetration rate of distributed generations; meanwhile, it can also improve the inertia level and damping capability of power system equivalently. First, the GESS based on power frequency drooping control is take as the research object of this paper, and its dynamic model on the DC voltage time-scale is established. Then, the model of a static synchronous generator is used to analyze the parameters that affect the energy storage system''s inertial level, damping effect and synchronization capability, as well as their corresponding influences. The analysis result shows that the links of droop control and power control are the main sources leading to the inertial and damping effect of GESS; moreover, an optimization design of droop coefficient and PI parameters of power loop can equivalently change the system''s inertial and damping characteristics. Simulation results prove that the conclusions in this paper is correct. The research in this paper will be helpful to the design of an effective control strategy for GESS, which can enhance the inertia level and damping capability of power grid, and improve the stable operation capability of distributed generation system and the power grid to be connected to.