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![33-bus distribution network configuration in 2040 [60].](publication/303359856/figure/fig2/AS:1086743793152022@1636111319408/33-bus-distribution-network-configuration-in-2040-60_Q320.jpg)
The need for developing new methodologies in order to improve power system stability has increased due to the recent growth of distributed energy resources. In this paper, the inclusion of a voltage stability index in distributed energy resources scheduling is proposed. Two techniques were used to evaluate the resulting multiobjective optimization...
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div>In modern power systems, small distributed energy resources (DERs) are considered a valuable source of flexibility towards accommodating high penetration of Renewable Energy Sources (RES). In this paper we consider an economic dispatch problem for a community of DERs, where energy management decisions are made online and under uncertainty. We m...
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... In addition, the initial investment can be a challenge for some small businesses. With the development of information technology and intelligent technology, the means and efficiency of energy scheduling optimization continue to improve [12][13]. For example, the use of intelligent energy management systems allows for real-time monitoring of energy usage and automatic adjustment of energy usage based on preset algorithms, resulting in more accurate and efficient energy scheduling. ...
With the acceleration of power marketization, there is a growing demand for optimization of power demand management and energy dispatch by industrial and commercial users, especially in achieving energy consumption efficiency and cost reduction. We adopt a two-layer optimization model combined with a time-sharing tariff system to efficiently allocate electricity resources by constructing an electricity demand response model for industrial and commercial users. The study results show that after implementing time-of-day tariffs, the cost of electricity for industrial and commercial users has been reduced by 15% on average. At the same time, the grid company’s revenue from electricity sales has been enhanced by 10%. In addition, a customer satisfaction survey found that customer satisfaction with the optimized power dispatch scheme increased by 20%. The study’s conclusion confirms that through scientific demand management and scheduling strategies, we can effectively improve the utilization efficiency of power resources and reduce costs, while ensuring customer satisfaction and achieving a win-win situation for supply and demand.
... Optimal automation devices planning in the distribution network has been done through the fuzzy-based mixed-integer linear programming and risk analysis in [23]. Authors in [24] have proposed a new method for energy scheduling of DERs in the distribution network for enriching the voltage stability. ...
Substantial increase in variability and uncertainty of net-load due to the higher shares of renewable resources from the generation sector has established the ramp problem in distribution networks. In this situation, maintaining a power balance becomes a challenging practice. To deal with this problem, the fluctuation of the net-load must be controlled during the operation timeslots. However, applying the limitation on the variability of the net-load results in high operational costs in the network. This paper aims to propose a flexibility-oriented approach for expansion planning of distributed energy resources (DERs) in order to reduce operational costs of the system under the situation of realizing control on the net-load’s fluctuations during the operation periods. To accomplish this aim, flexibility constraints are considered into the expansion planning of DERs to put a limit on the maximum hourly up and down ramp rates of the net-load. The proposed expansion planning has been formulated using mixed-integer linear programming to guarantee the optimality of the results. In addition, an interval optimization has been utilized to address uncertainties related to the output power of the clean resources, electricity price, and load consumption due to its computational efficiency. Finally, the effectiveness of the proposed expansion planning approach has been examined using the 33-bus distribution network. The results showed that the flexibility-oriented expansion planning of DERs enriches the flexibility of the distribution network under the condition of applying the limitations on the net-load’s fluctuations. Moreover, it can bring economic profit for the network in comparison with the state in which the expansion planning has been done without considering the flexibility constraints.
... This is the node that reaches the minimum voltage value at each simulation case. Figure 4 confirms that the injection of the active and reactive power in some nodes of the distribution network increases the voltage stability margin in all the nodes of the network, as demonstrated in [26]. This implies that the problem of the optimal location of capacitor banks and/or distributed generators is a subject currently under study, since these devices have substantial impacts regarding voltage stability, power losses, and voltage regulation improvements [27]. ...
This paper addresses the voltage stability margin calculation in medium-voltage distribution networks in the context of exact mathematical modeling. This margin calculation is performed with a second-order cone (SOCP) reformulation of the classical nonlinear non-convex optimal power flow problems. The main idea around the SOCP approximation is to guarantee the global optimal solution via convex optimization, considering as the objective function the λ-coefficient associated with the maximum possible increment of the load consumption at all the nodes. Different simulation cases are considered in one test feeder, described as follows: (i) the distribution network without penetration of distributed generation; (ii) the distribution network with penetration of distributed generation; and (iii) the distribution grid with capacitive compensation. Numerical results in the test system demonstrated the effectiveness of the proposed SOCP approximation to determine the λ-coefficient. In addition, the proposed approximation is compared with nonlinear tools available in the literature. All the simulations are carried out in the MATLAB software with the CVX package and the Gurobi solver.
... Hence it is already possible to establish parameters under which the voltage in system (7.2) (or (6.6)) can be stabilized [30,32]. (The corresponding characteristics of real behavior of the voltage and current are given in Fig. 5.17.) ...
... An area of stability of power system is the set of its modes, in which static stability is provided for a certain composition of the generators and a fixed circuit of the electric network. A surface bounding a set of stable regimes is called a boundary of region of static stability [32]. The stability regions are constructed in the coordinates of the parameters that affect the stability of the regime. ...
A new autonomous 4D nonlinear model with two nonlinearities describing
the dynamics of change of voltage and current in the contact railway electric network is offered. This model is a connection of two 2D oscillatory circuits for current and voltage in the contact electric network. In the found system for the defined values of parameters an existence of limit cycles is proved. By introduction of new variables this system can be reduced to 5D system only with one quadratic nonlinearity. The constructed model may be used for the control by voltage stability in a direct current power supply system.
The renewable energy sources, cogeneration and trigeneration units, loads that are connected together by means of a controller form a microgrid. In this paper is presented the optimization of the power cost for a small community (a microgrid) that comprises loads and four distributed sources (two photovoltaic, one wind turbine and one micro-hydro). In the microgrid there are also present electric vehicles. The power demand of the microgrid loads is added with the power required by the electric vehicles, which will be charged in a controlled manner. The optimization of the power cost is conducted by means of the fmincon function from the MATLAB software. Several charging scenarios of the electric vehicles will be considered, as well as the power cost from the power markets (day-ahead market and bilateral contracts market) in 2021 and 2022. The results give the optimal power cost for the microgrid and the best option to supply the microgrid.KeywordsOptimizationPower costMicrogridDistributed sourcesElectric vehiclesPower markets
With the rapid growth in DC energy-using equipment and distributed DC power, traditional AC distribution networks increasingly have problems, such as high loss and poor flexibility. This paper studies an AC/DC hybrid system integrated with multiport solid-state transformers (SSTs) and distributed renewable energy and proposes an optimal configuration model for the AC/DC hybrid system based on a coordinate operation strategy of SSTs and energy storage. First, the composition and topology of the AC/DC hybrid system are proposed. Then, a realistic efficiency model of a multiport SST is established. Based on the minimum operating loss of the SST, a multiport SST dual-machine parallel optimal operation strategy is established. A multi-energy storage system collaborative optimization operation strategy is established based on the electricity price, grid-connected mode and synergistic relationship among each energy storage system. Finally, based on the proposed AC/DC hybrid system model, the optimization objective of the system life cycle net present cost (NPC), constraints and GA algorithm are set. The proposed method is verified by industrial scenarios. The simulation results show that the proposed model can improve the economic and efficiency of the SST integrated AC/DC hybrid system.
