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Typhoon poses a significant challenge to the reliable and safe operation of power grids. A novel priority-load based preventive scheduling method that considers conventional generators and wind power is proposed to fully exploit the potential of wind power for resilience enhancement. First, the wind speed variation rule in different positions of the typhoon wind speed field is studied according to the characteristics of typhoon. Second, considering the influence of strong wind on the failure rates of transmission lines and tie-lines connecting the power sources and the main grid, the vulnerability curve is used to establish the fault model of lines during typhoon disasters. Third, the utility function of typhoon disaster is represented by the S-type curve, and satisfaction for typhoon resistance (SFTR) index is defined as the objective of coordinated scheduling model. The results show that SFTR can be increased by a factor of 27.9% by exploiting the wind power potential. Compared with the load shedding based method, the priority-load based method proposed in this paper can improve SFTR by 47.6% at most from the perspective of improving the capacity of satisfying important loads to enhance system resilience. [ABSTRACT FROM AUTHOR]

• A TEP model with risk constraints on wind power curtailment. • A novel convex relaxation is proposed to improve computational efficiency. • Case studies and analyses on the risk-based model and the proposed algorithm. Due to the inherent intermittency of wind power and the shortage of transmission capacity, a considerable amount of wind power cannot be delivered to load centres. The resulting curtailment of wind power poses a serious challenge to transmission planners. In this paper, we take advantages of the superquantile theory and formulate a risk-based transmission expansion planning (TEP) model to reduce the curtailment of wind power. Regarding its non-convexity and computation difficulty induced by increasing scenarios, we propose a convex relaxation method that can greatly improve computational efficiency. In the numerical study, the computational efficiency of the proposed solution strategy is verified. The comparable results demonstrate the effectiveness and superiority of the risk-based TEP model in terms of making a trade-off between the curtailment of wind power and the transmission investment cost. [ABSTRACT FROM AUTHOR]

Highlights • Generation, transmission and reactive power planning model has been developed. • Unit status and optimal transmission switching problems are considered. • A mixed-integer second order cone programming formulation is proposed. • The impact of different factors on wind power consumption are quantified. Abstract High penetration of renewable energy is one of the important feature of future power systems. However, the randomness and intermittence of renewable energy have brought new challenges to planners. To accommodate the uncertainty and variability of wind power, an innovative scenario-based stochastic model that incorporates generation, transmission, and reactive power planning is presented, considering spinning reserve, unit ramp rate, and current output of units. To consider reactive power flow and voltage, a second-order cone programming model based on relaxed AC optimal power flow is introduced. Moreover, unit status and optimal transmission switching are implemented to promote wind consumption, reduce congestion, and attain a more flexible topology. The proposed methodology organically combines operational constraints with planning issues. Finally, two modified test systems with high wind power integration are utilized to illustrate the effectiveness of the presented model. [ABSTRACT FROM AUTHOR]

(1) A tractable mathematical model for joint consideration of static and dynamic security in TEP (S&DSTEP) problems with large-scale wind power integration is proposed to improve the effectiveness of power systems in addressing both static security violations and transient instability. (2) The FCT-based N- k contingency constraints, which consider the correlation of the k component failures in an N- k contingency, are integrated into the proposed S&DSTEP model to find a balance between cost-effectiveness and safety in the planning scheme. Additionally, transient stability constraints are constructed in a linear form using the EEAC-based transient stability assessment (TSA) method, instead of DAEs. (3) An effective solution based on a decomposition strategy is proposed to address the S&DSTEP problem. The problem is split into a main problem for TEP and two subproblems for static security evaluation (SSE) and TSA. The integration of large-scale wind power into the power system is a global trend in response to climate change, however, the intermittent nature of wind power presents new challenges for planners. Conventional transmission expansion planning (TEP) methods, which only consider N-1 static security, may not ensure the security of multiple contingencies and transient stability in a large-scale wind power integration scenario. Incorporating N- k -based static constraints and dynamic constraints, such as differential-algebraic-equations-(DAEs)-based transient stability constraints, into TEP can result in a heavy computational burden and render the TEP model intractable. This paper proposes a tractable mathematical model (S&DSTEP) for joint consideration of static and dynamic security in TEP with wind power. The uncertain wind power generation is captured through selected scenarios and the model is divided into a TEP master problem and multiple sub-problems for evaluating static security and transient stability. Static security is determined by the use of fault chain theory (FCT), avoiding the need for enumerating all N- k contingencies, thus reducing the computational burden. Transient stability is analyzed through the use of stabilizing cuts generated from the extended equal-area criteria (EEAC) rather than dynamic constraints expressed as DAEs. The proposed model is verified on the modified New England 39-bus system and IEEE 118-bus system, demonstrating its ability to consider transient stability while being more computationally efficient compared to the robust method that directly incorporates all contingency scenarios. [ABSTRACT FROM AUTHOR]

A novel stochastic multi-area unit commitment (MAUC) framework is proposed to coordinate scheduling of generators and tie lines. In consideration of the randomness and volatility characteristics of wind energy, a worst-case based scenario selection method (SSM) based on the peak and valley shaving of the system, the ramping-up/down rates of net load, and the dispersion of uncertainty factors is presented to reduce the number of scenarios and improve the robustness of unit commitment (UC) schemes. Regarding the balance of efficiency and flexibility of tie-line scheduling, tie-line operation modes are established on the basis of the tie-line load rate (TLLR). Besides, the number of reversals of tie-line power flow directions during the entire scheduling period is also modeled. By linearizing the tie-line operation modes' equations, the MAUC can be converted into a mixed-integer linear programming (MILP) formulation. Case studies show that more wind energy can be consumed by connecting power systems through tie lines and coordinating scheduling of generators and tie lines. Expected energy not supplied (EENS) of scenario reduction techniques based on the clustering method, i.e. k-means, Gaussian mixture model (GMM) and Fuzzy C-means (FCM), are 147%, 38%, and 130% higher than that of the SSM. • A multi-area unit commitment model with tie-line operation modes is presented. • A novel scenario reduction method is proposed for unit commitment using time series data. • Different operation modes of tie lines are modeled and a linearized approximation is developed. • The influence of different operation modes on the unit commitment schemes is studied. [ABSTRACT FROM AUTHOR]