Design of LQG controllers for VSC HVDC transmission links using genetic algorithms

In this paper a genetic algorithm (GA) approach to designing controllers for a VSC HVDC terminal is described. The controller is required to have good time domain performance, actuator usage roll-off and robustness across a range of operating points. Suitable controllers are found by direct search for LQG controllers that fulfill the series of performance and robustness objectives at characteristic points within the operating range, as built into an objective function suitable for use with genetic algorithms. The idea is extended to include as extra variables the elements of the constant Youla parameter associated with the LQG controller. Different formulations of the objective function are discussed and compared and the results demonstrated on a non-linear model of the plant.