System and method for controlling voltage of a DC link of a power converter of an electrical power system

An electrical power system connected to a power grid, the electrical power system comprising:

• a doubly-fed asynchronous generator (DFAG);
• a power converter coupled to the DFAG, the power converter configured to convert a frequency of generated electric power from the DFAG to a frequency substantially similar to a frequency of the power grid, the power converter comprising a rotor-side converter, a line-side converter, a DC link, and a control module comprising a current damping device, the control module configured to perform one or more operations, the one or more operations comprising:
• operating the DC link to an optimum voltage set point that achieves steady state operation of the power converter;
• upon detection of one or more transient events occurring in the power grid, immediately increasing the optimum voltage set point to a higher voltage set point of the DC link by determining a voltage command for the optimum voltage set point of the DC link and applying the voltage command to the optimum voltage set point to allow the optimum voltage set point to increase towards the higher voltage set point, wherein determining the voltage command for the optimum voltage set point of the DC link further comprises receiving one or more rotor DC current regulator outputs and determining if the one or more rotor DC current regulator outputs are above a predetermined threshold, wherein the optimum voltage set point is immediately increased to the higher voltage set point of the DC link if the one or more rotor DC current regulator outputs are above the predetermined threshold, the one or more transient events being an indicator of one or more sub-synchronous control interaction (SSCI) conditions occurring in the electrical power system;
• and,
• operating the power converter at the higher voltage set point until the one or more SSCI conditions is damped, thereby optimizing control of sub-synchronous oscillations.