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• Developing an efficient and comprehensive framework based on the modified TS approach to eliminate the congestion of electrical lines. • Providing a VSM based strong TS scheme aiming to increase/reduce the active/reactive power capacity of system and the operation cost with regards to growing load demands in system, respectively. • Validating and assessing the proposed structure by implementing in large-scale grid. The escalating energy demand in the power system is known as a significant challenge for planning and expanding the future power system. Investigations have indicated that easing the line capacity of the power system can be an effective and efficient way to overwhelm this issue in the power system. This paper basically concentrates on providing a Transmission Switching (TS) based cost-effective approach to provide minimum voltage security margin (VSM) index while easing the active/reactive power capacity of the transmission lines. Note that this work is not only able to decrease the line loading of the system, but also can lead to a substantial reduction in the operation cost of the power system. However, the TS method can bring a significant challenge when it comes to the switching without imposing any restrictions on the number of switchings in a specific period of time. Considering the fact that the increase of switchings' number triggers the failure of the switches which, in turn, causes the outage of the lines and load interruption, one can conclude that the switch failure profoundly affects the rate of power network's outage. Since the TS method is able to prevent the lines from getting congested, it can improve the stability of the power system and significantly decrease the number of switchings of the lines. In this regard, the congestion management can be considered as an effective tool for improving the power system's stability and loading. This paper basically concentrates on employing the TS approach in the optimal power flow problem with the goal of decreasing the number of switchings of the lines, enhancing the SVM index, improving the loading of the power system and decreasing the operation cost of the system. The effectiveness of the studied model is tested and evaluated on 6-bus and 93-bus networks in GAMS software. [ABSTRACT FROM AUTHOR]

This paper basically concentrates on the impact of a price-maker energy storage unit (PMESU) on the operation of the power system. Recently, energy storage systems (ESSs) have attracted much attention as one of the renewable and pollution-free sources of energy and are applicable due to their exclusive advantages in power systems. In this paper, the ESS considered as a price-maker market player, which attempts to maximize the benefits of its competition in the market environment. The main operation problem of the PMESU represented as a bi-level optimization problem which comprises of nonlinear terms. First, a stochastic-based bidding/offering approach (SBOA) is considered which is less complex and takes lesser time to be solved compared to the MPEC method. Second, conditional Value-at-Risk (CVaR) method is used in order to control the risk of utilizing inoperative scenarios. Finally, the operation problem of the proposed PMESU is formed as a max-min problem in order to analyse the impact of the PMESU in the worst case condition from the perspective of the independent system operator (ISO). In addition, transmission switching (TS) method is utilized to minimize the system operation cost from the ISO point of view. The performance of the proposed method has been evaluated on an IEEE 9-bus test system which shows the authenticity and validity of this work. • Proposing SBOA based method in a stochastic scenario-based framework to model the correlated uncertainty. • Assessing the impact of market participants in a worse-case scenario from the ISO perspective. • Analyzing the mutual effect of risk-based participation procedure and the congestion situation. • Proposing a TS method to reduce the ISO cost considering the price-maker participant. [ABSTRACT FROM AUTHOR]

In this paper, a new modulation strategy based on the carrier-based switching strategy for the non-square direct matrix converters (MC) is proposed to control the active power of distributed generation (DG) units. In this strategy, the active power of DGs is controlled by the central input current control of the non-square direct MC independent from the voltage and frequency. Conventionally, each DG has a converter, and for supplying a load with N number of DGs, N number of converters are needed and each converter has its own modulation switching and control strategy to control the power output of each DG. Needless to say, in a microgrid with N number of DGs, the control strategy of each converter has more complex structure than that of a microgrid with one converter, and surely the former strategy entails more volume and price. Using the proposed converter in this paper, it is possible to supply a load with N number of DGs through one converter. Also, the power outputs of all DGs are controlled by a central control strategy. The proposed central control strategy is described and simulated for a typical microgrid. Experimental and simulation results validate the effectiveness of the proposed converter and the proposed strategy. The results demonstrate the applicability and efficiency of the system and verify the theoretical analysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Optimal allocation of a Wind-Storage Unit (WSU) is developed. • Congestion in energy transmission is considered. • The paper deals with price-maker WSU in electricity markets. • Unscented Transform is adapted to handle wind power uncertainty. This paper proposes an optimal allocation of a Wind-Storage Unit (WSU). Since transmission lines congestion varies according to the size, the location, and the operation of a generation unit in power systems, we assess the optimal location of a unit as a function of its variable operating condition. An independently operated wind-storage unit is assumed as a price-maker that seeks to maximize its market payoff without any prior information on optimally locating the wind and storage units. The main problem is provided as a tri-level optimization problem in which the first level is the WSU profit maximization, the second level is the power system operation cost minimization from the perspective of the independent system operator (ISO), and the third level is the maximization of the robustness of the system by using an appropriate transmission switching interval robust based chance constrained (TSIRC) method in order to minimize the operation cost of the system and transmission lines congestion problem. The tri-level model is converted to a bi-level optimization model by using Karush-Kuhn-Tucker (KKT) conditions provided as a Mathematical Programming with Equilibrium Constraint (MPEC). An effective binary particle swarm optimization algorithm (BPSO) is used in order to find the optimal location of the wind and storage units. Unscented Transform (UT) as a key element is suggested to model the uncertainties associated with the output power of the wind turbines. The proposed method is tested on an IEEE 24-bus test system and the results reveal the validity of this work. [ABSTRACT FROM AUTHOR]