H∞ control of single-machine infinite bus power systems with superconducting magnetic energy storage based on energy-shaping and backstepping

This article studies the H-infinity control problem for single-machine infinite bus power systems with superconducting magnetic energy storage (SMES) via simultaneous design of generator excitation control and SMES control. In the control system design, the exciter dynamics and unknown external disturbances are considered for practical implementation in power systems. A new synthesis framework is proposed to address the robust control problem of power systems with SMES. First, from the energy perspective, the interconnection and damping assignment (IDA) approach is applied to improve the transient performance of power systems. Second, by introducing the idea of virtual control in the design process, the authors obtain the solution of a partial differential equation that is a crucial point and cannot be obtained by using the traditional IDA method. Third, in order to enhance the robustness of the closed-loop system, the authors study the H-infinity control design that is challenging and difficult for power systems considering the above mentioned practical considerations. In addition, the authors use a novel equivalent generator model to avoid using unmeasurable infinite bus voltage. Simulation results also show the effectiveness and advantage of the proposed controller.