Dynamic improvement of induction generators connected to distribution systems using a DSTATCOM

The usage of distributed generation and devices based on power electronics have significantly increased in electric power distribution systems. In this context, induction generators have received more attention. However, it is known that such machines draw very large reactive currents during fault occurrence, which depresses the network voltage further and can lead to voltage instability. A solution for this problem is to employ local dynamic reactive power compensation. Therefore, in this work the behavior of a DSTATCOM to improve the voltage stability performance of distribution systems with induction generators is investigated based on three-phase non-linear dynamic simulations. Two control strategies for a DSTATCOM are analyzed: voltage and power factor control. In such studies, a DSTATCOM is simulated through a model based on controllable three-phase voltage sources, which has shown to be suitable for stability studies. Test results have indicated that a DSTATCOM with voltage control mode can improve the voltage stability margins.