Joint controller-communication topology design for distributed wide-area damping control of power systems

The recent development and deployment of the synchronized phasor measurement units (PMU) is allowing the wide-area monitoring and control of large-scale power systems. Furthermore, the integration of more communication technologies into the power system is giving an additional degree of freedom to the control design that may improve the performance of the overall system. Small-signal stability is an important requirement for power systems with the increasing number of distributed generation units. The oscillation modes of the power system have to be well damped in order to avoid contingencies such as blackouts. Wide-area controllers based on the real-time PMU measurements operating in centralized, distributed and decentralized manner have been widely proposed to damp the low-frequency oscillation of the large-scale interconnected power system. It has been shown that the damping performance can be improved by using the synchronized PMU data transmitted in real-time via communication network. However, only a few of the proposed methods take the structural constraint of the measurement data transmission into account. In this paper, we propose a method to design a distributed wide-area damping controller together with the communication topology in order to improve the damping performance of the power system. As a design strategy, first a decentralized controller that stabilizes the overall system is designed. Then, the damping performance is improved by designing the distributed control law, i.e. allowing the local controllers to exchange information. The problem is formulated as a mixed-integer optimization. Finally the proposed approach is evaluated in a five machine power system via a numerical simulation.