Grid impedance estimation with voltage-source converters
As renewable energy sources continue to become interconnected with the grid, Voltage-Source Converters(VSCs)have been used to interface generation units with the grid. But when the grid conditions are weakened that is when there is high and varying impedance, the stability of VSCs gets adversely aff...
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| Tipo de documento: | Dissertação de mestrado |
| Data de publicação: | 2025 |
| País: | España |
| Recursos: | Universitat Politècnica de Catalunya (UPC) |
| Repositório: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | Inglês |
| OAI Identifier: | oai:upcommons.upc.edu:2117/443429 |
| Acesso em linha: | https://hdl.handle.net/2117/443429 |
| Nível de acesso: | Acesso aberto |
| Palavra-chave: | Electric power system stability Impedance (Electricity) -- Measurement Adaptive control systems Voltage-source converter (VSC), Grid impedance estimation, Weak grid, Short-circuitratio (SCR), Recursive-least-square, Kalman filter, Signal injection, Hybrid adaptive estimation method (HAEM), Real-time control, Renewable energy integration Sistemes de distribució d'energia elèctrica -- Estabilitat Impedància (Electricitat) -- Mesurament Sistemes adaptatius Àrees temàtiques de la UPC::Enginyeria elèctrica |
| Resumo: | As renewable energy sources continue to become interconnected with the grid, Voltage-Source Converters(VSCs)have been used to interface generation units with the grid. But when the grid conditions are weakened that is when there is high and varying impedance, the stability of VSCs gets adversely affected. The traditional control measures are not appropriate in the low ShortCircuit Ratio (SCR); due to fixed grid impedances used. The present project fulfills that task by coming up with a powerful real-time grid impedance estimating system. Three estimation methods including Recursive Least Squares (RLS), Kalman Filter and Active Signal Injection were applied and tested in different SCR conditions. In a bid to resolve the drawbacks of the individual approaches, a new Hybrid Adaptive Estimation Method (HAEM) was put across. HAEMtakes the speed of RLS, noise resistance of the Kalman Filter and signal accuracy of injection, and applies an adaptive logic to dynamically enable components using the confidence of estimation and grid strength. The simulation results confirmed that simulations with HAEM needalotless estimation error, faster convergence rate and more stable system under control. It also facilitates real-time optimization of VSC control parameter including PLL bandwidth and gains of the current controllers. The project is an efficient way to guarantee stability and flexibility of VSCs in low and fluctuating grid conditions and enable more dependable integration of renewable sources of energy. |
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