| Short circuit study needs to be performed at the planning stage before connecting large generators with the electric grid. This study will reveal the impact of new generation on the fault levels of the grid. The fault levels will determine the rating of nearby equipment and setting of relays. However, a short circuit model of the new generation is required for this study. Although short circuit model of synchronous generator is well documented, such models are not adequately known for Wind Turbine Generators (WTGs).;This dissertation describes detailed time domain models of all types of WTGs, commonly classified as Type 1, Type 2, Type 3, and Type 4. Models of Type 1, 2, and 3 are validated using field data. Using these models, short circuit models are developed. Simulation and short circuit modeling of Type 2 WTG and wind farms having this type of WTGs are validated using actual field data from Mountain wind farm located in Wyoming, USA. Some insight into the selection of circuit breakers in the wind farm is also offered. A simple yet accurate equivalencing procedure for large wind farms is also proposed. This analysis also applies to Type 1 WTG.;Simulation and short circuit modeling of Type 3 WTG and wind farms having this type of WTGs are developed. This model assumes that the rotor circuit is crowbarred during fault. The model is validated using actual field data from Three Buttes wind farm in Wyoming, USA. Valuable insight about the status of crowbar during faults is achieved through this model.;Simulation and short circuit modeling of Type 4 WTG is described. Due to lack of validation data, the controls are designed to enable the WTG to comply with the most demanding grid codes. These controls are explained in detail, and short circuit model is developed.;Simulation of Type 3 WTG for enhanced LVRT capability is developed. The controls are innovatively designed to enable the WTG to comply with the most demanding grid codes, and are explained in detail. Insight is obtained into the short circuit model of this type of WTG. |
