Virtual Actuators for Wide-Area Damping Control of Power Systems

In this paper, a new approach to design fault-tolerant wide-area damping controllers (WADCs) is presented. Use of actuator redundancy to achieve higher reliability has always been an accepted engineering design technique and is used in this study to help ensure power system security. In our proposed method when an actuator fails or is unavailable (e.g., due to loss of communication), the supervisory controller redistributes the control signals to the remaining actuators. The WADC is initially designed to provide satisfactory damping. In the next step, virtual actuators (VAs) are designed to manage actuator failures without the need to redesign the nominal WADC. By inserting this reconfiguration block between the nominal WADC and the new actuator, there is no need to retune the WADC and the performance of the fault-free system can be recovered. Our proposed block is independent of the nominal WADC and does not need any information beyond that an actuator is unavailable. The approach is applied to Kundur's two-area system, and the 39-bus New England system. Numerical results show the effectiveness of the proposed method subjected to different failures.