Power system harmonic reduction and voltage control using DFIG converters as an active filter

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 grid-connected 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 (i) using a simple and effective active filtering technique and (ii) 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.