Fault current generation by STATCOM

Abstract

The penetration level of renewable energy resources increases in the power grid since they do not have a negative impact on the environment as the conventional power plants. Renewable energy resources are not required, by the current grid codes, to contribute to restore the voltage stability. Moreover, they do not contribute to the short circuit current during fault disturbance. As a consequence, the reliability as well as the voltage stability of the power grid have been negatively affected during the disturbance. In this thesis, STATCOM model has been developed, with different priority control strategy, to increase the fault current as well as to enhance the voltage stability to support the renewable energy resources to meet the grid requirements. Three priority control strategy has been considered: 1) STATCOM with only positive sequence control strategy; 2) STATCOM with only negative sequence control strategy; 3) STATCOM with positive and negative sequence control strategy with equal ratio of 0.5. Each strategy has its own advantage and disadvantage in terms of increasing the positive voltage and reducing the negative voltage in power grid. Furthermore, there level of contribution to the short circuit current depends on the type of fault and the grounding of transformer. Using the STATCOM device to enhance the performance of renewable energy resources during the disturbance will help to increase the penetration of renewable energy resources to the grid without having a negative impact on the voltage stability and the grid reliability.