On-line stability control of power systems integrated with distributed generation systems

Because of the certain stochastic nature of renewable generation, large-scale distributed generation systems can impose unpredictable impact on the stability of their integrated transmission systems. This paper demonstrates that power system oscillations can be caused by unpredictable changes of operating conditions of integrated distributed generation systems and hence presents a novel method of power system damping control by applying the operational principle of immune system. The proposed immune damping control is to mimic the immune response, to identify and respond to disturbance, and keep a healthy level of power system oscillation damping. The proposed artificial immune control acts by monitoring the health index in real time and performing immune feedback to maintain required healthy level of power system damping such that oscillations are suppressed effectively. It does not need to establish detailed parametric model of studied power system, neither its operating conditions, for the design of the damping controller. Hence it is a robust and modeling-free scheme of power system damping control. In the paper an example power system integrated with large-scale distributed generation systems is presented. Simulation results demonstrate the effectiveness and robustness of the artificial immune control method in variable circumstances of power system operation.