Delay-aware co-designs for wide-area control of power grids

In this paper we address the problem of wide-area control of power systems in presence of different classes of network delays. We pose the control objective as an LQR minimization of the electro-mechanical states of the swing equations, and present a so-called arbitration approach by which the flexibilities of the communication network such as scheduling policies, bandwidth, etc., can be exploited to co-design a delay-aware state feedback control law. A key feature of our method is that it retain the samples of the control input until a desired time instant using shapers before releasing them for actuation. This essentially means that we regulate the delays entering our controller. Hence, unlike the traditional robust control designs reported in the power system literature, our design is delay-aware, not delay-tolerant. They are, therefore, much more reliable and practical to implement. We illustrate our results using a 50-bus, 14-generator, 4-area power system model, and show how the proposed arbitrated controller can guarantee significantly better closed-loop performance than traditional robust controllers.