Modelling and Analysis of Variable Speed Wind Turbines with Induction Generator during Grid Fault

Abstract

The produced electrical power from wind has dramatically increased in the last years. Therefore today’s wind turbines, which typically are centralised in wind parks, have a significant influence on the power production. Network operators have to ensure well function power transmission and supply to their customers. For this reason, there exist different requirements in the distribution and transmission net, which deal with controlled power production, connect/ disconnect requirements and behaviour during faults in the grid. Several Network operators have also introduced special grid connection requirements for wind turbines, which are mainly based on existing requirements for power plants. These requirements are a challenge for wind turbine producers. New hardware and control strategies have to be developed and existing control strategies have to be changed. The important changes are due to pitch control, power control, grid connection and error handling. The changes should not affect the already existing advantages of the wind turbines control strategies. The paper contributes a discussion of the existing grid codes and furthermore a control strategy developed by Vestas is presented.