Sensitivity‐based approach for real‐time evaluation of transient stability of wind turbines interconnected to power grids

Abstract

The growth of utilisation of wind turbines in the contemporary power systems, the transient stability (TS) evaluation has turned to a challenging issue in the modern power grids. An innovative and high-precision real-time method based on the transient energy function (TEF) is proposed which aims to evaluate the TS of power system in the presence of wind turbines. The proposed method is designed so that the initial point of TEF is calculated precisely by performing offline calculations. Structure preserving is used to guarantee the accuracy of the proposed method in order to consider the details of power system modelling. Moreover, the proposed method takes into account the impacts of the wind turbines controllers utilising new formulation based on a sensitivity-based approach. The new formulation is utilised to calculate the effects of the controllers reflected in the potential terms of TEF during the fault occurrence. As a result, in addition of considering fault-on trajectory, the latter technique causes reducing the computational burden and also guarantees accurate real-time assessment of TS. The simulation results demonstrate the efficiency and also comprehensiveness of the proposed method in calculation of critical clearing time and TS assessment.

Minimizing the undesirable effect of coupling capacitor voltage transformer on DFT-based phasor estimation method

“…It must be noted that, due to severe disturbances in power system, the system frequency may differ from its nominal value f 0 . The latter causes undesirable instability in estimating phasor, and as a result, it must be considered in phasor estimation of numerical relays.…”

Probabilistic analysis of current‐transformer dimensioning: A criterion for determining the level of exposure to saturation

“…It must be mentioned that in this paper, only the first cycle of fault‐current signal after fault inception is utilized to calculate τ dc , I dc , I 1 , and α 1 . As mentioned in the studies of Tajdinian, Seifi, and Allahbakhshi, Tajdinian et al, and Kundur, Balu, and Lauby, the frequency changes very slowly after fault because of power‐system inertia. Therefore, in the first cycle after the fault, the frequency remains almost unchanged.…”

Enhanced sensitivity‐based decentralised framework for real‐time transient stability assessment in bulk power grids with renewable energy resources

“…It can be found that the TDS is able to effectively handle CH1 and CH2, but at the cost of extensive computational burden due to the time‐consuming time‐domain simulations. Although some efforts have been made in some literature to speed up the process [11], its computational burden is still high as compared to other approaches, such as the one in [21].…”