Synchronized Sampling Technology-Based Compensation for Network Effects in WAMS Communication
Wide Area Measurement System (WAMS)-based closed-loop power system control faces lots of challenges such as network effects in WAMS communication which include network-induced delays, data packet dropouts and packet disordering, etc. As of now, design of wide area feedback controller robust against those network effects typically relies on linear matrix inequalities (LMIs) methods. However, because LMIs methods results in conservative controller and sometimes feasible solution cannot be found although they exist, it is still difficult to implement wide area feedback control in real power systems. In order to overcome those problems, a more practical scheme is presented in this paper for WAMS-based closed-loop power system control. In the new scheme, a GPS receiver is configured at the wide area feedback controller/actuator which can calculate feedback signals' delays by comparing the time differences between their own clocks and time stamps of feedback signals. Then, by using synchronized sampling technology again, trajectories of power systems are extrapolated to compensate those network effects in WAMS communication. Therefore, in the new scheme, hardware technologies (e.g., GPS-based synchronized sampling technologies) instead of complicated LMIs methods are used to deal with network effects in WAMS communication. So the new control scheme can overcome the conservative nature from LMIs methods and can be implemented practically in real power systems. Simulation results are given to show the effectiveness of the proposed control scheme.