Abstract: Impact of dynamic interactions between converter control systems on stability of permanent magnet synchronous generator (PMSG) based wind farms is investigated in this paper. A closed-loop interconnected model is established, wherein the phase locked loop (PLL) is treated as a feedback subsystem, and then correlations of dynamic interactions between the subsystems are examined with modal analysis of open-loop and closed-loop system. Based on the established model, an instability mechanism caused by dynamic interactions between PMSGs is revealed from the perspective of open-loop modal resonance. Under the condition of open-loop modal resonance, i.e., an open-loop PLL mode in the feedback subsystem close to an oscillation mode of open-loop plant subsystem on complex plane, strong interactions between the subsystems may degrade system damping. Finally, a power system with PMSG based wind farms is used as an example to demonstrate and validate analysis and conclusions obtained in this paper. Meanwhile, impact of many factors on open-loop mode resonance is also explored, including system operation conditions (such as connection strength with the grid, PMSG injected power level), and reactive power control structures and parameters.
王旭斌, 杜文娟, 王海风. 一种直驱风电场中换流器控制系统间动态交互引起系统的失稳机理分析[J]. 电网技术, 2018, 42(8): 2423-2430.
WANG Xubin, DU Wenjuan, WANG Haifeng. Mechanism Analysis of Instability Caused by Dynamic Interactions Between Converter Control Systems in PMSG Based Wind Farms. POWER SYSTEM TECHNOLOGY, 2018, 42(8): 2423-2430.
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