Transient synchronization stability analysis of PLL-based VSC using Lyapunov's direct method. (October 2022)

• Record Type: Journal Article
• Authors: Wang, Tong; Ji, Taipeng; Jiao, Dian; Li, Yongda; Wang, Zengping
• Is Part Of: International journal of electrical power & energy systems. Volume 141(2022)
• Publication Date: 2022-10
• Subjects: Transient synchronization stability -- Transient energy function -- Equal area criterion -- Phase-locked loop (PLL) -- Outer-loop control; Electrical engineering -- Periodicals; Electric power systems -- Periodicals; Électrotechnique -- Périodiques; Réseaux électriques (Énergie) -- Périodiques; Electric power systems; Electrical engineering; Periodicals; 621.3
• DOI: 10.1016/j.ijepes.2022.108135
• Languages: English
• ISSNs: 0142-0615

Abstract

Highlights: The control model of VSC is built, with the consideration of the impact of the outer-loop control on the PLL control. Based on the motion equation, the EAC method is employed to exhibit the synchronization instability mechanism of VSC analysis. A more accurate energy function is derived by considering the interaction between the outer-loop control and PLL control. Abstract: Direct method has been a promising development for decades due to its interpretability. This paper presents the transient energy function based on the Lyapunov's direct method to quantitatively assess the synchronization stability for PLL-based voltage source converter (VSC). First, the reduced order model of VSC is built, with the consideration of the impact of the outer-loop control system on the dynamic synchronization process of the phase-locked loop (PLL). Then the motion equation of PLL-based VSC considering the interaction between the outer-loop control and PLL control is derived. Furthermore, the equal area criterion (EAC) method is employed to exhibit the synchronization instability mechanism of PLL-based VSC. Next, the transient energy function on the basis of the motion equation is proposed by the first integral method considering the outer-loop control, and the critical energy value is determined by the controlling unstable equilibrium point (UEP) method. Based on the grid-connected equivalent circuit of multiple-VSCs system, the transient energy function for multi-VSCs system is further proposed. Finally, the VSC-Infinite bus system is used as the test system to investigate the effectiveness and advantage of the proposed transient energy function.