Interactions and multivariable design of STATCOM AC and DC voltage control

A static synchronous compensator (STATCOM) may be equipped with several controllers to perform multiple control functions. However, in this paper, a study case of negative interactions between STATCOM AC and DC control is reported, which indicates that the conventional arrangement of multiple controllers for STATCOM various control functions may not always be appropriate. Hence, it is suggested that the multiple control functions of the STATCOM are implemented by a single multivariable controller, which is designed by treating the STATCOM installed in a power system as a multi-input multi-output control system. In this paper, an example is demonstrated, where a single two-variable controller is successfully designed to perform both STATCOM AC and DC voltage control function.