Digital and laboratory implementation of a generalised minimum variance controller for an HVDC link

The paper demonstrates the use of a generalised form of minimum variance controller in a composite HVDC-AC power system for enhancing system transient performance and its implementation in a laboratory simulator system. The controller input is the generator power deviation and the output a stabilising signal which is added to the current order of the rectifying converter. The cost function incorporates the system input and setpoint variations in addition to the system output. Laboratory and digital simulation results are encouraging and again reveal the capability of the DC link in damping AC system oscillations and the feasibility of incorporating modern controls in composite power systems