Paper Title
Harmonic Filtering in a Power Grid with Power Generation

With the advancement of technology, electricity generation using wind has drawn an increased attention in the world. As the amount of wind power integrated into the system is increased, it causes power quality and stability problems. Therefore power utilities are developing stringent grid codes which are to be satisfied by the wind power producers. Voltage control capability, reactive range capability, frequency control ability and fault ride through capability are among the major requirements stipulated in the grid codes. Due to the variable speed operation capability of Doubly Fed Induction Generators (DFIGs), they are becoming popular in wind power generation. The voltage control of the DFIG wind farm has been identified as the latest challenge with the present grid code requirements. In this paper, for bus voltage control and to reduce power system harmonics, the active filtering technique is used in the mechanism of wind turbine control. Here a gridconnected doubly fed induction generator (DFIG) is considered in a wind turbine. In addition to harmonics that are related to the DFIG, a nonlinear load is also added to the system to simulate loads that produce more harmonics. The active filtering approach is implemented to mitigate current and voltage harmonics, which is one of the main concerns of distribution systems. A bus voltage control strategy is also used for this purpose. The main advantages of this article are using a simple and effective active filtering technique and applying a voltage control method to mitigate the mentioned harmonics. The presented methodology is examined in both local and remote control conditions and also for both normal and contingency (load change) situations. Simulation results obtained from applying the presented method on a distribution test system confirm suitable performance of the proposed strategy to mitigate current and voltage harmonics. Keyword - WECS, Doubly fed induction generator (DFIG), Harmonic reduction, Active filter, Voltage control,