发电技术 ›› 2020, Vol. 41 ›› Issue (6): 650-658.DOI: 10.12096/j.2096-4528.pgt.19151

• 能源互联网 • 上一篇    下一篇

基于虚拟同步发电机的微电网并离网安全控制策略

郭亦宗(), 郭创新()   

  • 收稿日期:2020-09-10 出版日期:2020-12-31 发布日期:2021-01-12
  • 通讯作者: 郭创新
  • 作者简介:郭创新(1969), 男, 博士, 教授, 博士生导师, 主要研究方向为智能电网风险调度、综合能源系统等, 本文通信作者, guochuangxin@zju.edu.cn
    郭亦宗(1997), 男, 硕士研究生, 主要研究方向为综合能源安全控制、需求侧管理, guoyizong@zju.edu.cn
  • 基金资助:
    国家自然科学基金项目(51877190)

Security Control Strategy of Micro-grid Between Grid-connected and Off-grid Based on Virtual Synchronous Generator

Yizong GUO(), Chuangxin GUO()   

  • Received:2020-09-10 Published:2020-12-31 Online:2021-01-12
  • Contact: Chuangxin GUO
  • Supported by:
    National Natural Science Foundation of China(51877190)

摘要:

微电网作为综合能源系统的一大分支,广泛用于分布式电源的就地消纳。而随着冷、热、气等逐渐引入,对微电网安全控制的要求也越来越高。针对微电网的孤岛和并网建模及两运行状态之间的过渡过程进行分析,提出了改进虚拟同步发电机(virtual synchronous generator,VSG)模型下的控制策略。通过引入合适的虚拟阻抗,有效模拟了同步电抗的特性,保证孤岛运行基本稳定的同时,使得并网至孤岛的切换在该模型下不需要添加额外的控制部分即可完成平滑过渡;针对孤岛至并网的切换,提出了改进型的预同步控制模型,该模型能快速准确地跟踪电网电压幅值、频率以及相位。最后,结合实际算例对所构造的模型在Matlab/Simulink环境下进行仿真,验证了所提模型的正确性及其优势。

关键词: 微电网, 无缝切换, 虚拟同步发电机(VSG), 虚拟阻抗, 改进预同步控制

Abstract:

As a major branch of integrated energy system, micro-grid is widely used in the local consumption of distributed generation. With the introduction of cold, heat and gas, the requirement of micro-grid security control is becoming higher and higher. The grid-connected and off-grid mode of micro-grid and the transition process between two operating states were analyzed, furthermore, a control strategy based on improved virtual synchronous generator (VSG) model was proposed. By using appropriate virtual impedance, the characteristics of synchronous reactance were effectively simulated, which ensured the stability of off-grid operation and makes the transition from grid-connected mode to off-grid mode smooth without adding additional control. An improved pre-synchronization control model was proposed for the switching from off-grid mode to grid-connected mode, which could accurately and quickly track the voltage amplitude, frequency and phase. Finally, the model was simulated in Matlab/Simulink environment with a practical example to verify the correctness and advantages of the proposed model.

Key words: micro-grid, seamless switch, virtual synchronous generator (VSG), virtual impedance, improved pre-synchronization control

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