Determining the size and location of variable speed wind turbines for reducing power losses and improving voltage profile

Abstract

Due to the voltage level and current of feeders in distribution systems, power loss is high in such networks. With the proliferation of distributed generations, it has become more important to determine their location and rating. These goals can be obtained according to different purposes such as improving the voltage profile. Unlike fixed speed wind turbines, the variable speed type can produce or absorb the reactive power. Hence, this paper specifies the placement and sizing of variable speed wind turbines based on a multi-objective function and according to the reactive power management. In the first step, the variable speed wind turbine is modeled by using the practical curve and Levenberg–Marquardt algorithm and then, the objective functions are optimized simultaneously to achieve the locations and sizes. Also, the impact of wind speed uncertainty on the functions is evaluated. To validate the results, a comparison between variable speed and fixed speed wind turbines is also presented. The proposed model is implemented on an IEEE 33-bus standard test system and the results show a significant (42%) decrease in power loss by adding variable speed wind turbines. However, the investment cost is also increased. Moreover, with considering the uncertainty, power loss and investment cost are increased by about 8% and 15%, respectively. However, the robustness of the system is enhanced against the wind speed fluctuations.