A STATCOM is a dynamic reactive device built using voltage source converter (VSC) technology, the same basic technology used for type-4 wind plants, solar plants, and battery systems. A STATCOM operating in voltage-control mode injects VARs into the network when the voltage is low and absorbs VARS when the voltage is high.
The fault response of a STATCOM that does not inject negative-sequence current can be represented in OneLiner using a Voltage Controlled Current Source (VCCS) model. STATCOM modeling with a VCCS is limited in scope because the prefault current output of the VCCS model must be restricted for compatibility with the linear network prefault voltage solution.
In OneLiner Version 14, Appendix J in User’s Manual described how to model utility-scale type-4 wind plants and solar plants using the voltage-controlled current source object (VCCS). That explanation is no longer needed because OneLiner Version 15 has a dedicated Converter-Interfaced Resource model for simulating type-4 wind plants, solar plants, and battery systems. Therefore, Appendix J has been repurposed to describe how the VCCS can be used to model a STATCOM that injects positive-sequence reactive power to control voltage.