• Shruti Sisodia
• Raghunandan Baghel
• Neha Singh

Now a-day power networks all over the world need to transfer bulk amount of power. This has resulted in required vast interconnection of grids for assuring reliability, security, stability and economic operation. The challenges to ensure smooth system operation with stressed grid and averting system blackout provided the stimulus for research on voltage security. Voltage stability indices aid the security studies. Real-time voltage security assessment is based on synchronized pharos measurement obtained from phasor measurement units (PMUs). For fast accurate handling of data to synthesize information in order to estimate system security state decision tree (DT) approach of data mining is opted. Power system operating constraints are soft constraints, to implement the situation in real-time and improve decision making abilities at the overlapping and conflicting security boundaries present scheme adopts fuzzy decision tree (FDT). The decision tree is trained offline considering past representative operating conditions, identify critical attributes as security predictors and periodically updated incorporating new operating conditions for robustness improvement. The status of critical attributes are obtained from PMUs and compared with thresholds priory defined by FDTs. The decision at the leaf nodes considers the whole path, i.e. from the root to the terminal node including membership function of security predictors. As classification and prediction by decision trees are fast, reliable, comprehensible the present scheme employs FDT and resolve conflict in decision making by prognosticating system security status with the aid of voltage stability indices (VSI) and thereby easing the operators’ role and to some extent alleviating the risk of failure. The indices helps to identify security status from the solution of basic power flow equations, i.e. system real-time measurements such as voltage magnitude, phase angle, bus injected power, branch flows etc.

Voltage security assessment, Pharos measurement unit, Decision tree, Fuzzy decision tree, Voltage stability indices

"Assessment Of Online Voltage Security based on Voltage Stability Indices and FDT", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.11, Issue 4, page no.f635-f644, April-2024, Available :http://www.jetir.org/papers/JETIR2404569.pdf

"Assessment Of Online Voltage Security based on Voltage Stability Indices and FDT", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.11, Issue 4, page no. ppf635-f644, April-2024, Available at : http://www.jetir.org/papers/JETIR2404569.pdf