DATE & TIME: 11th December, 2018 (Tuesday), 3:00 pm, ESB 244.
SPEAKER: Adusumilli Bala Surendra (EE15D200).
Guide: Dr. B Kalyan Kumar
Long-term voltage stability can be assessed with the use of static analysis techniques. Continuation power flow analysis (CPF) has been widely used to determine the maximum loadability/steady-state voltage stability limit from active power vs. voltage curves (PV curves) for a deterministic set of loads and power generations. But, in presence of uncertainty conventional analysis techniques may give erroneous results. Probabilistic-based methods like Monte Carlo (MC) simulations were first used in order to assess steady-state voltage stability under uncertainty, where each uncertain variable is assumed to have a certain probability distribution function (PDF) and a large number of samples are collected to get various loading and generation scenarios. However, MC simulations are computationally burdensome. A self-validated range arithmetic method called affine arithmetic (AA) can be used for uncertainty analysis that requires less computational time and gives reasonably good accuracy. However, AA operations lead to more noise terms and hence overestimation of bounds. In the present work, a modified AA (modAA)-based CPF is proposed to determine PV curve bounds by considering uncertainties associated with active and reactive power injections at all buses in the system. The proposed method reduces the overestimation caused by the AA operations and gives more accurate solution bounds. The proposed modAA-based CPF analysis is tested on 5-bus test case, IEEE 57, European 1354 and Polish 2383-bus systems. The simulation results with the proposed method are compared with MC simulations and AA-based CPF analysis. The simulation results clearly demonstrated the efficacy of the proposed method.