Voltage control loop for mitigating flicker in a grid-forming inverter-based resource

A method for mitigating voltage disturbances at a point of interconnection of a grid-forming inverter-based resource connected to a power grid due to a flicker effect, the method comprising:

• receiving, via a controller, a voltage feedback from an external controller;
• generating, via the controller, a current vector reference signal based on the voltage feedback, the current vector reference signal containing a frequency component of the voltage disturbances;
• dynamically adjusting a transfer function of a regulator of the controller based on the frequency component to account for the flicker effect;
• and
• regulating, via the regulator, a voltage vector command of the grid-forming inverter-based resource to mitigate the voltage disturbances at the point of interconnection,
• wherein dynamically adjusting the transfer function of the regulator of the controller based on the frequency component comprises adjusting the transfer function of a d-axis current proportional-integral regulator of a voltage control loop of the controller from a proportional-integral regulator to a proportional-resonant regulator.

A system for mitigating voltage disturbances at a point of interconnection of a grid-forming inverter-based resource connected to a power grid due to a flicker effect, the system comprising:

• a converter controller comprising a proportional-integral regulator, wherein the converter controller comprises a voltage control loop and a frequency control loop, wherein the voltage control loop comprises a d-axis power proportional-integral regulator and a d-axis current proportional-integral regulator, the converter controller comprising a processor for performing a plurality of operations, the plurality of operations comprising:
• receiving a voltage feedback from an external controller;
• generating a current vector reference signal based on the voltage feedback, the current vector reference signal containing a frequency component of the voltage disturbances;
• generating a transfer function of the proportional-integral regulator based on the frequency component to account for the flicker effect;
• and
• dynamically adjusting the transfer function of the proportional-integral regulator of the converter controller based on the frequency component,
• wherein the regulator of the converter controller regulates a voltage vector command of the grid-forming inverter-based resource to mitigate the voltage disturbances at the point of interconnection,
• wherein dynamically adjusting the transfer function of the proportional-integral regulator of the converter controller based on the frequency component comprises adjusting the transfer function of the d-axis current proportional-integral regulator from a proportional-integral regulator to a proportional-resonant regulator.