Comparison of SVCs And D-STATCOMs to control voltage violations of fixed speed induction generators

Though the new wind turbine generator (WTG) technology offers fault ride-through capability (FRT), many systems still consist of old induction generators. These induction generators typically have the problems of voltage limit violations which result in undesirable tripping. Their response to abnormal conditions like faults has to be studied for proper reactive compensation to contain the voltage violations within limits. The two options to contain dynamic violations considered are SVCs and D-STATCOMs. The locations and the capacities of these devices must cater to all possible tripping conditions. In this paper, SVC placement is done based on the improvement of voltage stability index. The D-STATCOMs can be more in number and are located near to WTG to provide better compensation. This paper compares the above two options for a sample 33 bus distribution system using the dynamic models of the compensation devices using PSCAD/EMTDC.