Grid connected voltage source inverter control under unbalanced and distorted grid conditions
Author
Neishabouri, Bizhan
Term
4. term
Education
Publication year
2023
Submitted on
2023-06-02
Pages
84
Abstract
As electricity systems shift to renewable energy, wind turbines must operate reliably with the power grid. A key component is the grid-side inverter, which converts the turbine’s output into grid-compatible AC. In real networks the grid voltage is often distorted—for example by unbalanced transmission line impedances or by other equipment—which can cause synchronization and grid-connection problems. This project examines how filtering these distortions can improve robustness, focusing on an existing solution called MSRF-PLL, a type of phase-locked loop that helps keep the inverter synchronized with the grid even when the voltage is not ideal. We combine theory, simulated case studies, and experiments to evaluate the controller’s stability and performance. The goal is to assess how well MSRF-PLL can maintain a reliable grid connection under distorted grid-voltage conditions.
I takt med at elsystemet omstilles til vedvarende energi, skal vindmøller fungere stabilt sammen med elnettet. En central del er netside-inverteren, som omdanner møllens strøm til elnet-kompatibel vekselstrøm. I praksis er netspændingen ofte forvrænget – for eksempel på grund af ubalancer i transmissionslinjernes impedans eller andet udstyr – hvilket kan give problemer med synkronisering og nettilslutning. Dette projekt undersøger, hvordan filtrering af disse forvrængninger kan øge robustheden, med fokus på en eksisterende løsning kaldet MSRF-PLL, en type fase-låst sløjfe, der hjælper inverteren med at holde takt med nettet, selv når spændingen ikke er ideel. Vi kombinerer teori, simulerede cases og eksperimenter for at vurdere regulatorens stabilitet og ydeevne. Formålet er at bedømme, hvor godt MSRF-PLL kan opretholde en stabil nettilslutning under forvrængede netspændingsforhold.
[This apstract has been rewritten with the help of AI based on the project's original abstract]