Tuning of Voltage Controller Gain for Multiple STATCOM Systems

STATCOMs with voltage control are known for their fast reaction time to stabilize the grid voltage. For optimal dynamic performance it is essential to use the correct gain settings for the PI voltage regulation controller, adapted for different states of operation. This paper shows the equation to calculate the accurate value for the gain setting in the voltage controller. The inner control behavior with enabled droop control is considered as well as the strength of the grid. After this the influences between STATCOMs installed in parallel in one bus is shown and the adaption of the gain to take this into account is calculated. The equations are validated by analytic aspects as well as by simulations. This enhances the existing control solution in industry and allows constant dynamic performance under various system changes in future grids.