A phase-locked loop using ESO-based loop filter for grid-connected converter: performance analysis

• Published in: Control theory and technology Vol. 19; no. 1; pp. 49 - 63
• Main Authors: Guo, Baoling, Bacha, Seddik, Alamir, Mazen, Pouget, Julien
• Format: Journal Article
• Language: English
• Published: Guangzhou South China University of Technology and Academy of Mathematics and Systems Science, CAS 01.02.2021; Springer Nature B.V; School of Engineering,(HES-SO)University of Applied Sciences and Arts of Western Switzerland,Sion,1950 Valais,Switzerland%Institute of Engineering Grenoble,University Grenoble Alpes,CNRS,G2Elab,38000 Grenoble,France%Institute of Engineering Grenoble,University Grenoble Alpes,CNRS,GIPSA-Lab,38400 Saint Martin D'Hères,France; Springer
• Subjects: Complexity; Computational Intelligence; Control; Control and Systems Theory; Control stability; Control systems design; Converters; Electric power; Engineering; Engineering Sciences; Frequency analysis; Frequency domain analysis; Frequency measurement; Hardware-in-the-loop simulation; Mechatronics; Optimization; Phase locked loops; Phase locked systems; Research Article; Robotics; Stability analysis; State observers; Systems Theory; Grid disturbances; Phase-locked loop; Power hardware-in-the-loop (PHIL) test; Loop filter; Extended state observer; Tuning approach; Stability analysis; Noises attenuation; Phase margin; Grid-connected converters; Power hardware-in-the-loop(PHIL)test
• ISSN: 2095-6983; 2198-0942
• DOI: 10.1007/s11768-021-00036-0

An extended state observer (ESO)-based loop filter is designed for the phase-locked loop (PLL) involved in a disturbed grid-connected converter (GcC). This ESO-based design enhances the performances and robustness of the PLL, and, therefore, improves control performances of the disturbed GcCs. Besides, the ESO-based LF can be applied to PLLs with extra filters for abnormal grid conditions. The unbalanced grid is particularly taken into account for the performance analysis. A tuning approach based on the well-designed PI controller is discussed, which results in a fair comparison with conventional PI-type PLLs. The frequency domain properties are quantitatively analysed with respect to the control stability and the noises rejection. The frequency domain analysis and simulation results suggest that the performances of the generated ESO-based controllers are comparable to those of the PI control at low frequency, while have better ability to attenuate high-frequency measurement noises. The phase margin decreases slightly, but remains acceptable. Finally, experimental tests are conducted with a hybrid power hardware-in-the-loop benchmark, in which balanced/unbalanced cases are both explored. The obtained results prove the effectiveness of ESO-based PLLs when applied to the disturbed GcC.