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In our recent work [1] , we constructed a reduced-order model of the Western Electricity Coordinating Council (WECC) power system using mathematically derived parameters from real Synchrophasor data. These parameters include inter and intra-area impedances, inertias, and damping factors for aggregate synchronous generators representing five geographical, and yet coherent, areas of WECC. In this paper, we use this reduced-order model as a tool to design a supplementary controller for a Static VAr Compensator (SVC), located at the terminal bus of one of the aggregate generators. Wide-area feedback consisting of phase angle and frequency measurements from Phasor Measurement Units (PMUs) in the other areas is used to design this controller. The objective is to damp the inter-machine oscillation modes of the reduced-order model, which in the full-order system corresponds to inter-area oscillations. The controller input is chosen via statistical variance analysis, and its parameters are tuned to improve the damping factors of the slow modes. The model is implemented in a real-time digital simulator, and validated using a wide range of disturbance scenarios. The closed-loop system is observed to be highly robust to all of these disturbances as well as the choice of operating points. Detailed experimental analyses of the capacity of the SVC to satisfy the damping specifications of supplementary control are also presented via multiple contingencies. The results are promising in aiding damping of inter-area modes in WECC, especially at a time of increasing penetration of wind and other renewable resources. [ABSTRACT FROM AUTHOR]

Highlights: [•] Combination of optimal reclosing of circuit breakers and SVC is proposed for power system transient stability enhancement. [•] The performance of the proposed combination of optimal reclosing and SVC is compared with the combination of conventional reclosing and SVC. [•] The performance of the proposed combination of optimal reclosing and SVC is better than that of the combination of conventional reclosing and SVC. [•] Combined operation of optimal reclosing and SVC can be considered as an effective means for power system transient stability enhancement. [ABSTRACT FROM AUTHOR]

• Yet there are few studies for the extremely short-term forecasting of wind power. • Since the proposed approach is nonlinear, it provides more accurate modelling than the ARMA approach. • The proposed approach only uses the EKF algorithm to update the parameters which makes it suitable for online implantation. • It is robust against noisy easements and probabilistic behavior of the wind speed profile. • A proper model for the wind farm to simulate and evaluate the performance of the SVC based on real data is proposed. The inherent time-varying nature of the wind farm power causes undesired voltage flicker in the power network. In order to mitigate the flicker to enhance the performance of the wind power system with very fast dynamics, the static VAr compensator (SVC) is utilized. However, the SVC operates with some delays which negatively affects its performance. This persuades us to predict the reactive power of the wind farm to compensate for the real-world delay. The predicted reactive power is then utilized in the SVC. Therefore, this paper develops a novel fuzzy one-step-ahead prediction approach for the wind farm reactive power. The proposed fuzzy prediction uses a Takagi-Sugeno (TS) fuzzy representation whose unknown parameters are tuned online based on an extended Kalman filter (EKF). The wind farm is modeled as a time-varying current source which its amplitude and phase change every 0.01 s. A large set of the actual data of a wind farm in Manjil, Iran is gathered and directly utilized in the simulation process. Several flicker indices are calculated to evaluate the proposed prediction method. The obtained results show the performance enhancement and flicker mitigation of the suggested power scheme. [ABSTRACT FROM AUTHOR]

• The main contributions of this work are summarized as follows. • Considering different load types, their outage costs, and their daily load profiles to find the best UFLS scenario with lowest interruption cost. • Performing the PLSA after UFLS by means of reactive power control apparatus. • Checking the adaptive UFLS/PLSA scenarios by transient stability analysis. • Finding the optimal UFLS/PLSA scenarios all day long. • Damping the background voltage and frequency fluctuations. The conventional under frequency load shedding (UFLS) strategies disconnect the preset amount of the load from the power grid in specific steps. These approaches ignore the daily load variations and the total outage costs, leading to a non-optimal solution. This paper proposes an adaptive UFLS scheme that considers the daily profiles of the different load types to minimize the total outage cost. To obtain the exact amount of the load to be shed, the dynamic performance of the load clusters is modeled. Furthermore, a series of post load-shedding corrective actions (PLSA) are implemented after the UFLS to satisfy the voltage constraints, using the installed reactive power control apparatus and static VAR compensators (SVCs). Two static (frequency-domain) and transient (time-domain) indexes are defined to evaluate the feasibility of possible UFLS/PLSA scenarios. The promising solutions are ranked and the most favorable ones are embedded in a number of look-up tables. The proposed UFLS/PLSA approach is applied to the main grid as well as the potential islands. The performance of the proposed adaptive UFLS/PLSA approach is tested on the IEEE 39-bus system via numerous scenarios, and the results show feasibility, fast and optimal performance of the proposed method. [ABSTRACT FROM AUTHOR]