Analysis of the application of a grid emulator to conduct grid compliance tests for multi-megawatt Wind turbines : a contribution towards ground testing of wind turbines

Averous, Nurhan Rizqy; de Doncker, Rik W. (Thesis advisor); Jacobs, Georg (Thesis advisor)

1. Auflage. - Aachen : RWTH Aachen University (2020, 2021)
Book, Dissertation / PhD Thesis

In: E.ON Energy Research Center ; PGS, Power Generation and Storage Systems 95
Page(s)/Article-Nr.: 1 Online-Ressource : Illustrationen, Diagramme

Dissertation, RWTH Aachen University, 2020

Abstract

In the context of the ground testing to streamline the deployment process of wind turbines, this thesis presents a comprehensive analysis on the application of a grid emulator to conduct grid compliance tests of wind turbines (WT). The focus of the thesis lies on the flicker measurements caused by the output power fluctuations of WTs, mainly due to the wind turbulence and the tower shadowing effect, as well as the low-voltage ride-through (LVRT) tests. Firstly, the design requirements are derived based on the behavior of the device under test (DUT) and the regulatory frameworks. Afterwards, the application of a multi-megawatt grid emulator employing interleaved multi-megawatt converters is analyzed. Next to the filter design to meet criteria on the voltage quality, the emulation of a high grid impedance at the point of common coupling (PCC) is presented in this thesis. This appears to be the worst scenario when it comes to the flicker emission and the LVRT capability of WTs. The results show that the grid emulator concept fulfills the derived design criteria in terms of the voltage quality and dynamic. The stability limit of the coupled system between the grid emulator and DUT can be well predicted by only considering the passive elements of the DUT. Hence, with the presented grid emulator, LVRT tests and flicker measurements can be conducted on a wind turbine test bench with a good accuracy.