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 co ntroller in a composite HVDC-AC power system for enhancing system transient performance and its implementation in a laboratory simulator system. The c ontroller input is the generator power deviation and the output a stabilisi ng 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 ar e 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.