Dynamic estimation of power system stability in different Kalman filter implementations

Abstract

Voltage collapse is still the biggest threat to the transmission system. There are many approaches that have been explored to predict the point of voltage collapse. However, it is still lacking of information that related to current system state. With the advancement of Phasor Measurement Units (PMUs) technology, it provides an alternate pathway to improve the existing power system state estimation. Hence, it was of interest to develop better methods that could give a preliminary warning before the voltage collapse. This paper concerns for the development of real-time system monitoring methods to give a timely warning in the power system. The algorithm to predict the points of collapse is based on the assumption that voltage instability is closely related to the maximum load ability of a transmission network. Therefore, the Thevenin impedance is equalled to the apparent load impedance at the points of collapse. Numerous methods such as Discrete Kalman Filter (Dm), Extended Kalman Filter (EKF) and Unscented Kalman Filter (UKF) are being implemented into the realtime voltage instability predictor to track the Thevenin parameters. The test results are tested on Malaysia's power system 132 kV-2-bus and 10-bus systems. The results are compared based on the early-warning index of voltage collapse. The results of DKF method are set as the reference for comparison purpose between EKF method and UKF method. The test results shown that EKF method provided better results by decreasing of 0.1169 p.u. for 2-bus system and 0.0338 p.u. for 10-bus system. In the meanwhile, UKF method provided increasing values of 0.4262 p.u. for 2-bus system and 0.1522 p.u. for 10-bus system. The overall purpose of this research is to develop methods that in provide early warning for an emerging stability problem. In order to achieving the research's objectives, derivation of the index for early warning of the point of collapse is completed. The performance of each method used throughout this research is based on the analyzed results for the points of voltage collapse.

Dynamic State Estimation of Electric Power Systems Using Kalman Filtering Techniques

“…The dynamic state estimation [14] is a simple technique for tracking state variable changes within a power system. Besides, there is no precise physical modelling of the system's time behavior in the monitoring of changes.…”

Analyzing Impact of Distributed PV Generation on Integrated Transmission & Distribution System Voltage Stability—A Graph Trace Analysis Based Approach

“…Hence, all case studies in this paper model the transmission system as an unbalanced, three-phase system. Moreover, voltage stability is a function of maximum load-ability of system buses [17], which in turn depends upon available generation resources, network topology, load patterns, and VAR support [18]. With increasing DER penetrations, these parameters change, thus leading to variability in voltage stability.…”

“…There is a growing consensus among the scientific and power community on the need to model the transmission and distribution infrastructure as a single entity. In addition to modeling, it is also necessary to develop power flow analysis techniques to solve such integrated systems [7][8][9][10][11][12][13][14][15][16][17][18][19]. This emphasis has led to the introduction of advanced methods for modeling and simulation of power systems such as co-simulation frameworks, like HELICS/FNCS [20] and Graph Trace Analysis [21].…”

“…Previous work discussed utilization of Graph Trace Analysis (GTA) power flow for integrated T&D systems, where the entire system is modeled as unbalanced, multi-phase, with varying topologies [1,17,28]. A matrix-free, GTA-based power flow was employed and found to be computationally efficient, robust, and capable of solving multiple topologies in a single model.…”

Integrated Transmission-and-Distribution System Modeling of Power Systems: State-of-the-Art and Future Research Directions

“…Steady-state voltage stability of transmission systems is a function of maximum load carrying ability of system buses [3], which in turn depends on the available generation resources, network topology, load patterns, and volt ampere reactive or Var support [4]. DERs connected to the distribution system impact these parameters, which leads to variability in voltage stability [5].…”