Graduation - 2024 - December (Open Access)

Permanent URI for this collection

https://scholar.sun.ac.za/handle/10019.1/125747

Browse

Browsing Graduation - 2024 - December (Open Access) by browse.metadata.advisor "Beukes, H. J."

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    Synchronization and Frequency Estimation Techniques for Grid-Connected Inverters
    (Stellenbosch University, 2024-12) Bootha, Dawid Frans; Beukes, H. J.; Stellenbosch University. Faculty of Engineering. Dept. of Electrical & Electronic Engineering.
    The increasing integration of renewable energy sources into the power grid necessitates advanced synchronization and frequency estimation techniques to ensure stability and reliability. This thesis presents a comprehensive study on the design, implementation, and optimization of Phasor Measurement Units (PMUs) for grid-connected inverters, focusing on their synchronization and frequency estimation systems. A detailed analysis of various synchronization structures, including the Synchronous Reference Frame Phase-Locked Loop (SRF-PLL), Decoupled Double Synchronous Reference Frame PLL (DDSRF-PLL), and Double Second Order Generalized Integrator Frequency- Locked Loop (DSOGI-FLL), is provided. The performance of these systems is evaluated under different t est c onditions, i ncluding h armonics a nd d ynamic d isturbances i n the voltage waveforms. The Frequency Phase-Locked Loop (FPLL) structure is developed that leverages the best performance attributes of both the PLL anf FLL systems. The thesis also includes the experimental validation of the proposed PMU structures, conducted in a controlled laboratory environment. Digital twins of each PMU structure were developed in Simulink to compare their performance using key performance metrics. Furthermore, this work explores the optimization and tuning of the PMU parameters to minimize frequency estimation errors, total vector error (TVE), and settling times. The results of these optimizations demonstrate improvements in the accuracy and response time of the PMUs. In conclusion, this thesis contributes to the development of robust synchronization and frequency estimation systems for grid-connected inverters, offering valuable i nsights into the design and performance evaluation of PMUs. The findings have practical implications for enhancing the stability and efficiency of future power grids.