• CSCD核心库收录期刊
  • 中文核心期刊
  • 中国科技核心期刊

ELECTRIC POWER CONSTRUCTION ›› 2022, Vol. 43 ›› Issue (3): 131-140.doi: 10.12204/j.issn.1000-7229.2022.03.014

• Energy Internet • Previous Articles     Next Articles

Critical Short-Circuit Ratio of Small-Signal Stability for a Grid-Connected Renewable Power Generation System Based on Virtual SynchronousGenerator Control

KANG Siwei1(), DONG Wenkai2(), GUO Shiran1(), SUN Hongjun1(), XIE Xiaorong2()   

  1. 1. CNOOC Renewable Energy, Shanghai 200335, China
    2. State Key Lab of Control andSimulation of Power Systems and Generation Equipment (Deptartment of Electric Engineering,Tsinghua University), Beijing 100084, China
  • Received:2021-07-22 Online:2022-03-01 Published:2022-03-24
  • Contact: KANG Siwei E-mail:kangsw@cnooc.com.cn;596167281@qq.com;guoshr2@cnooc.com.cn;sunhj5@cnooc.com.cn;xiexr@tsinghua.edu.cn
  • Supported by:
    Science and Technology Project of China National Offshore Oil Corporation(YXKY-SHANGHAI-2020-01)

Abstract:

Studies in recent years have shown that in addition to the ability to provide frequency and voltage support for AC system, the voltage-controlled virtual synchronous generators (VSG) are also of good adaptability to the operation conditions of weak grid. To improve the stability of a grid-connected VSG and exploit its advantages to the full, in this paper, a method to determine the critical short-circuit ratio (SCR) of the gird-connected VSG system and related stability criteria are explored considering small-signal stability (SSS). To do so, the small-signal model of a grid-connected VSG system is established and sorted into a form of negative feedback system with two-input and two-output units at first. Secondly, according to the generalized Nyquist criterion, a SSS criterion for the system considering impact of grid strength is proposed and a critical SCR is defined, which can provide guidance and reference for planning of gird-connected VSG systems in the future. Finally, methods proposed in the paper are validated through study cases.

Key words: renewable power generation, virtual synchronous generator (VSG), small-signal stability, gird strength, critical short circuit ratio (CSCR)

CLC Number: