Real-time topology monitoring brings in high communication investments and operating costs. This paper proposes a real-time topology monitoring method using only voltage magnitude measurements from partial critical buses for real-time communication, which reduces communication requirement and network traffic greatly. A three-step angle-free optimization algorithm framework is designed to estimate current topology. Firstly, we perform load forecasting and power flow calculation to generate enough pseudo measurements, which makes up the lack of real-time measurements. Secondly, weighted least square method and improved extended Kalman filter are used to eliminate static and dynamic noises. These state estimation methods help provide more accurate measurements for topology tracking, especially with plenty of pseudo-measurements and accumulated error caused by load forecasting. Finally, we design an angle-free topology tracking algorithm based on voltage magnitude measurements of critical buses to estimate and correct current topology. Numerical results on IEEE 33-bus case show that our framework with only 10 critical buses reaches a high real-time topology monitoring accuracy F1 of 91.59% and thus can greatly reduce communication requirement.
Keywords Topology tracking, limited real-time measurements, communication costs, angle-free topology tracking algorithm, state estimation