Reduction of Inrush Current and Voltage Drop by Selecting Optimum Reactors in Induction Generators

Induction generator has many advantages compared to the synchronous generator in terms of robust, cost and easy to maintenance. So the induction generator has been widely applied to small or medium size hydropower station in recent years. The induction generator generates a large inrush current corresponding to the starting current of the induction motor at the moment of grid connection. This inrush current can cause a voltage drop of the grid as well as the consumer load equipment, which may degrade the stability of the electric quality. It is very important to reduce the voltage drop due to the inrush current in order to improve the electric quality and increase the supply of the induction generator. In this study, we propose a solution to reduce the voltage drop and the inrush current by adjusting the parameters of the reactor tap and adjusting the appropriate operating pattern of the water turbine generator. As a result of the analysis, it was confirmed that the voltage drop can be adjusted within the allowable range.