中国电力 ›› 2019, Vol. 52 ›› Issue (9): 118-125.DOI: 10.11930/j.issn.1004-9649.201805058

• 电网 • 上一篇    下一篇

直驱风电机组与弱电网交互作用稳定分析

万玉良1, 朱玲2, 项颂1, 刘福锁2, 陈璐1, 王佳佳2   

  1. 1. 国网内蒙古东部电力有限公司, 内蒙古 呼和浩特 010020;
    2. 南瑞集团(国网电力科学研究院)有限公司, 江苏 南京 211106
  • 收稿日期:2018-05-12 修回日期:2018-12-25 出版日期:2019-09-05 发布日期:2019-09-19
  • 作者简介:万玉良(1972-),男,高级工程师,从事电力系统自动化电网安全稳定管理研究,E-mail:1678424852@qq.com;朱玲(1986-),女,高级工程师,从事电力系统新能源并网安全稳定分析研究,E-mail:zhuling@sgepri.sgcc.com.cn
  • 基金资助:
    国网内蒙古东部电力有限公司科技项目(SGMD0000DDJS1701168)。

Interactive Stability Analysis between Direct-Drive Wind Turbinesand Weak Power System

WAN Yuliang1, ZHU Ling2, XIANG Song1, LIU Fusuo2, CHEN Lu1, WANG Jiajia2   

  1. 1. State Grid Inner Mongolia East Power Co., Ltd., Hohhot 010020, China;
    2. NARI Group Corporation/State Grid Electric Power Research Institute, Nanjing 211106, China
  • Received:2018-05-12 Revised:2018-12-25 Online:2019-09-05 Published:2019-09-19
  • Supported by:
    This work is supported by the Science and Technology Project of State Grid Inner Mongolia Eastern Power Co., Ltd. (No.SGMD0000DDJS1701168).

摘要: 网侧变流器作为新能源发电单元与电网的接口,对电网系统的安全稳定运行有着重要影响。以直驱型风电机组网侧变流器为研究对象,采用小扰动数学建模方法,建立了包含锁相环和电压前馈环节的网侧变流器及其控制的数学模型,推导了其dq轴系下动态阻抗解析表达式,发现其阻抗在次同步频带呈负电阻(负实部)特性,与弱交流电网连接存在次同步频带不稳定现象。基于上述现象分析了影响稳定的关键控制参数及其特性,结果表明,增强网架强度、优化锁相环控制参数、增大电压前馈滤波频率可在一定程度上降低系统次同步振荡的风险,最后采用电磁暂态仿真验证了上述分析。

关键词: 动态阻抗, 直驱风电机组, 振荡, 锁相环, 电压前馈控制

Abstract: As an interface between new energy power generator units and a power grid, the grid-side converter plays an important role in maintaining the safe and stable operation of power system. Based on the grid-side converter of direct-drive wind turbines, a math model of grid-side converter and its control including the phase-locked loop (PLL) and voltage feed-forward control is established in the paper using the small disturbance mathematic modelling method, and the dynamic impedance analytical expression under dq axis is derived. It is found that the impedance has the features of negative resistance (negative real part) in the subsynchronous frequency band and is unstable in subsynchronous frequency band when connected with weak power grid. The key control parameters that influence the system stabilities are analyzed. The results indicate that the subsynchronous oscillation risks can be reduced to some extent through enhancing the power grid strength, optimizing the PLL control parameters and increasing the voltage feed-forward filtering frequency. Finally, the above analytical results were verified by electromagnetic transient simulation.

Key words: dynamic impedance, direct-drive wind turbine, oscillation, phase-locked loop, voltage feed-forward control

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