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Global Stability Analysis for Synchronous Reference Frame Phase-Locked Loops
  • Zhiyong Dai ,
  • Guangqi Li ,
  • Mingdi Fan
Zhiyong Dai
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Guangqi Li
Xidian University

Corresponding Author:[email protected]

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Mingdi Fan
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This paper analyzes the global stability of synchronous reference frame phase-locked loops (SRF-PLLs), from a large signal viewpoint. First, a large signal model of SRF-PLL is accurately established, without applying any linearization method. Then, According to the phase portrait tool, the global stability of SRF-PLL is discussed in the nonlinear frame. Compared with existing methods, the proposed analysis, not relying on small signal model and linearization method, provides a global discussion of SRF-PLL stability. Some novel discoveries are as follow: 1) SRF-PLL has infinite equilibrium points, including stable points and saddle points; 2) Although saddle points are unstable in local regions, there still exists two special lines for each saddle point, and SRF-PLL converges to a certain saddle point when the initial states are on its special lines. 3) These special lines of saddle points divide the global region of SRF-PLL into infinite small regions. A Lyapunov-based discussion proves that SRF-PLL converges to different stable points, when the initial states are in the different small regions. The experiment results have been verified the global stability analysis of SRF-PLL.
Oct 2022Published in IEEE Transactions on Industrial Electronics volume 69 issue 10 on pages 10182-10191. 10.1109/TIE.2021.3125655