Repository logo
 

Theses and dissertations (Engineering and Built Environment)

Permanent URI for this collectionhttp://ir-dev.dut.ac.za/handle/10321/10

Browse

Filters

2021 - 20222

Settings

Has files: YesSubject: search.filters.subject.Wind power plants

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Stability analysis of the Namibian power grid with integration of large offshore wind farms using a VSC-HVDC scheme
    (2022-05-13) Mbaimbai, Nicky K.; Davidson, Innocent Ewaen
    The use of the wind for electrical power production has seen a meteoric increase due to the wind being a free and abundantly available resource, especially when the site is offshore. The wind resource along the Namibian coastline could therefore be implemented to develop offshore wind farms that would enable Namibia to meet its steadily increasing power demand. The efficient transmission of bulk power from offshore sites to the onshore AC grid is widely achieved through voltage source converter-based high voltage direct current (VSC-HVDC) schemes. This study aims to investigate the power system stability response of the Namibian network, particularly in terms of rotor angle stability, to the integration of large offshore wind farms. A single machine infinite bus (SMIB) model developed in DIgSILENT PowerFactory was used as a test bed for the study. Transient and small-signal stability analysis in relation to different fault scenarios on the main transmission lines were then carried out after doubly-fed induction generators (DFIGs) representing offshore wind farms were integrated into the SMIB model. The same methodology was applied on a reduced model of the NamPower network. DigSILENT PowerFactory’s VSC-HVDC offshore wind farm template model was integrated to a reduced model of the NamPower network. The entire network was then subjected to different fault scenarios along backbone transmission lines, major busbars and the HVDC link at different penetration levels of offshore wind power. The study established that the integration of large offshore wind farms using a VSC-HVDC scheme to the reduced NamPower network negatively affected the network's transient and small-signal stability. However, there was a positive impact on the voltage levels of the network due to the reactive power compensation supplied by the VSC-HVDC link. The VSC-HVDC link also maintained low-voltage ride-through of the offshore wind farms during faults that comply with the Namibian transmission grid code.
  • Thumbnail Image
    Item
    Numerical and experimental investigations of the impacts of the integration of wind energy into distribution network
    (2021-12-01) Behara, Ramesh Kumar; Ojo, Evans E.; Akindeji, Timothy Kayode
    The growing needs for electric power around the world has resulted in fossil fuel reserves to be consumed at a much faster rate. The use of these fossil fuels such as coal, petroleum and natural gas have led to huge consequences on the environment, prompting the need for sustainable energy that meets the ever increasing demands for electrical power. To achieve this, there has been a huge attempt into the utilisation of renewable energy sources for power generation. In this context, wind energy has been identified as a promising, and environmentally friendly renewable energy option. Wind turbine technologies have undergone tremendous improvements in recent years for the generation of electrical power. Wind turbines based on doubly fed induction generators have attracted particular attention because of their advantages such as variable speed, constant frequency operation, reduced flicker, and independent control capabilities for maximum power point tracking, active and reactive powers. For modern power systems, wind farms are now preferably connected directly to the distribution systems because of cost benefits associated with installing wind power in the lower voltage networks. The integration of wind power into the distribution network creates potential technical challenges that need to be investigated and have mitigation measures outlined. Detailed in this study are both numerical and experimental models to investigate these potential challenges. The focus of this research is the analytical and experimental investigations in the integration of electrical power from wind energy into the distribution grid. Firstly, the study undertaken in this project was to carry out an analytical investigation into the integration of wind energy in the distribution network. Firstly, the numerical simulation was implemented in the MATLAB/Simulink software. Secondly, the experimental work, was conducted at the High Voltage Direct Centre at the University of KwaZulu-Natal. The goal of this project was to simulate and conduct experiments to evaluate the level of penetration of wind energy, predict the impact on the network, and propose how these impacts can be mitigated. From the models analysis, the effects of these challenges intensify with the increased integration of wind energy into the distribution network. The control strategies concept of the doubly fed induction generator connected wind turbine was addressed to ascertain the required control over the level of wind power penetration in the distribution network. Based on the investigation outcomes we establish that the impact on the voltage and power from the wind power integration in the power distribution system has a goal to maintain quality and balance between supply and demand.