| 摘要: |
| 针对虚拟同步发电机(virtual synchronous generator, VSG)并网运行时在有功指令和电网频率扰动下存在输出有功暂态振荡问题，提出了一种基于暂态阻尼增强的改进VSG控制策略。首先，基于状态反馈理论，分析了所提控制方法的物理意义，即该策略是通过在常规VSG有功控制环中加入角频率和电磁功率的高频分量来增强系统暂态阻尼。然后，基于所提的控制方法，建立了系统的有功控制环闭环小信号模型，并通过对系统特征根的根轨迹进行分析揭示了所提控制方法对VSG有功功率振荡抑制的影响。并给出了各状态反馈参数的设计准则，指导了反馈系数的设计。所提控制策略能有效抑制有功指令突变和电网频率突变时VSG输出有功功率振荡，并且不会影响系统的稳态特性。最后，通过仿真和实验对比分析，表明所提控制方法具有更好的有功功率振荡抑制效果，并且能消除稳态偏差，且适用于不同电网强度。 |
| 关键词: 虚拟同步发电机 有功功率振荡 暂态阻尼 根轨迹分析 状态反馈 |
| DOI：10.19783/j.cnki.pspc.230362 |
| 投稿时间：2023-04-06修订日期：2023-08-09 |
| 基金项目:湖南省自然科学基金项目资助(2018JJ2367)；湖南省高新技术产业科技创新引领计划项目资助(2020GK4061)；湖南省企业科技特派员计划项目资助(2021GK5055) |
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| Improved VSG control strategy based on transient damping enhancement |
| JIANG Shiming1,2,TANG Jie1 |
| (1. School of Information Science and Engineering, Shaoyang University, Shaoyang 422000, China; 2. Hunan Provincial
Key Laboratory of Rural Informatization Services in Southwest Hunan, Shaoyang 422000, China) |
| Abstract: |
| Virtual synchronous generator (VSG) faces the problem of the output active power oscillation under active power command and grid frequency disturbance under grid-connected operation. In view of this, an improved VSG control strategy based on transient damping enhancement is proposed. First, based on state feedback theory, the physical meaning of the proposed control method is analyzed, and the system transient damping is enhanced by adding high-frequency components of angular frequency and electromagnetic power to the conventional VSG active power control loop. Second, based on the proposed control method, a closed-loop small signal model of the active power control loop is established, and the system characteristic root locus is used to analyze the impact of the proposed control method on VSG active power oscillation suppression. Design guidelines of various state feedback parameters are also provided to guide feedback coefficient design. The proposed control method can effectively suppress VSG output active power oscillations caused by sudden changes in active power commands and grid frequency, without affecting the system's steady-state characteristics. Finally, the simulation and experimental results demonstrate that the proposed method has better active power oscillation suppression performance, eliminates steady-state deviation, and can be applicable to different grid strengths. |
| Key words: virtual synchronous generator (VSG) active power oscillation transient damping root locus analysis state feedback |
