scholarly journals Stochastic Expansion Planning of Various Energy Storage Technologies in Active Power Distribution Networks

2021 ◽  
Vol 13 (10) ◽  
pp. 5752
Author(s):  
Reza Sabzehgar ◽  
Diba Zia Amirhosseini ◽  
Saeed D. Manshadi ◽  
Poria Fajri

This work aims to minimize the cost of installing renewable energy resources (photovoltaic systems) as well as energy storage systems (batteries), in addition to the cost of operation over a period of 20 years, which will include the cost of operating the power grid and the charging and discharging of the batteries. To this end, we propose a long-term planning optimization and expansion framework for a smart distribution network. A second order cone programming (SOCP) algorithm is utilized in this work to model the power flow equations. The minimization is computed in accordance to the years (y), seasons (s), days of the week (d), time of the day (t), and different scenarios based on the usage of energy and its production (c). An IEEE 33-bus balanced distribution test bench is utilized to evaluate the performance, effectiveness, and reliability of the proposed optimization and forecasting model. The numerical studies are conducted on two of the highest performing batteries in the current market, i.e., Lithium-ion (Li-ion) and redox flow batteries (RFBs). In addition, the pros and cons of distributed Li-ion batteries are compared with centralized RFBs. The results are presented to showcase the economic profits of utilizing these battery technologies.

2021 ◽  
Vol 11 (5) ◽  
pp. 1972
Author(s):  
Alejandro Garces ◽  
Walter Gil-González ◽  
Oscar Danilo Montoya ◽  
Harold R. Chamorro ◽  
Lazaro Alvarado-Barrios

Phase balancing is a classical optimization problem in power distribution grids that involve phase swapping of the loads and generators to reduce power loss. The problem is a non-linear integer and, hence, it is usually solved using heuristic algorithms. This paper proposes a mathematical reformulation that transforms the phase-balancing problem in low-voltage distribution networks into a mixed-integer convex quadratic optimization model. To consider both conventional secondary feeders and microgrids, renewable energies and their subsequent stochastic nature are included in the model. The power flow equations are linearized, and the combinatorial part is represented using a Birkhoff polytope B3 that allows the selection of phase swapping in each node. The numerical experiments on the CIGRE low-voltage test system demonstrate the use of the proposed formulation.


2021 ◽  
Vol 11 (2) ◽  
pp. 627
Author(s):  
Walter Gil-González ◽  
Alejandro Garces ◽  
Oscar Danilo Montoya ◽  
Jesus C. Hernández

The optimal placement and sizing of distributed generators is a classical problem in power distribution networks that is usually solved using heuristic algorithms due to its high complexity. This paper proposes a different approach based on a mixed-integer second-order cone programming (MI-SOCP) model that ensures the global optimum of the relaxed optimization model. Second-order cone programming (SOCP) has demonstrated to be an efficient alternative to cope with the non-convexity of the power flow equations in power distribution networks. Of relatively new interest to the power systems community is the extension to MI-SOCP models. The proposed model is an approximation. However, numerical validations in the IEEE 33-bus and IEEE 69-bus test systems for unity and variable power factor confirm that the proposed MI-SOCP finds the best solutions reported in the literature. Being an exact technique, the proposed model allows minimum processing times and zero standard deviation, i.e., the same optimum is guaranteed at each time that the MI-SOCP model is solved (a significant advantage in comparison to metaheuristics). Additionally, load and photovoltaic generation curves for the IEEE 69-node test system are included to demonstrate the applicability of the proposed MI-SOCP to solve the problem of the optimal location and sizing of renewable generators using the multi-period optimal power flow formulation. Therefore, the proposed MI-SOCP also guarantees the global optimum finding, in contrast to local solutions achieved with mixed-integer nonlinear programming solvers available in the GAMS optimization software. All the simulations were carried out via MATLAB software with the CVX package and Gurobi solver.


Subject Batteries and energy storage. Significance With the rise of renewable energies and electric vehicles, a major transition is underway in global energy markets. The key to facilitating growth in both areas is the falling cost of lithium-ion (Li-ion) batteries. Cheaper batteries have helped to reduce the cost of electric vehicles and are making large-scale energy storage on the power grid -- which is a necessity if renewables are to continue growing -- a reality. Impacts Secure access to lithium, cobalt and other battery-related materials will be vital to economic development. Competition over resources to build batteries could see protests, skirmishing and illegal trade where the resources are. Companies face higher due diligence demands when sourcing battery-producing materials.


Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2405
Author(s):  
Samar Fatima ◽  
Verner Püvi ◽  
Ammar Arshad ◽  
Mahdi Pourakbari-Kasmaei ◽  
Matti Lehtonen

Power distribution networks are transitioning from passive towards active networks considering the incorporation of distributed generation. Traditional energy networks require possible system upgrades due to the exponential growth of non-conventional energy resources. Thus, the cost concerns of the electric utilities regarding financial models of renewable energy sources (RES) call for the cost and benefit analysis of the networks prone to unprecedented RES integration. This paper provides an evaluation of photovoltaic (PV) hosting capacity (HC) subject to economical constraint by a probabilistic analysis based on Monte Carlo (MC) simulations to consider the stochastic nature of loads. The losses carry significance in terms of cost parameters, and this article focuses on HC investigation in terms of losses and their associated cost. The network losses followed a U-shaped trajectory with increasing PV penetration in the distribution network. In the investigated case networks, increased PV penetration reduced network costs up to around 40%, defined as a ratio to the feeding secondary transformer rating. Above 40%, the losses started to increase again and at 76–87% level, the network costs were the same as in the base cases of no PVs. This point was defined as the economical PV HC of the network. In the case of networks, this level of PV penetration did not yet lead to violations of network technical limits.


An ‘ideal* converter would accept the power flow of a 3-phase a.c. system operating with sinusoidal voltage and current, and, without energy storage and by a continuous process, convert to or from d.c. Present-day converters rely, however, on repetitive circuit switching operations, more than 12 per cycle being generally uneconomic despite the cost of the energy storage components required in damping circuits and in the filters to maintain acceptable waveforms. Analysis of the operation of such converters is based on the mathematics of repetitive transients (Laplace and Fourier) and on the use of a d.c. transmission simulator, an extensive model at 10 -7 scale in power, which is also necessary in the development of complex electronic control circuits. There exists a great background of experience contributing to the design of most components of the power circuit. In contrast, the development of the switching device, whether thyristor stack or mercury arc valve, calls for advances in the state of art, both in scientific appreciation and in technology, which must be supported by full scale tests. There is little immediate prospect of the theoretical ‘ ideal * converter, but this is unimportant, provided that development leads to enhanced overall reliability.


Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1866
Author(s):  
Zahid Javid ◽  
Ulas Karaagac ◽  
Ilhan Kocar ◽  
Ka Wing Chan

There is an increasing interest in low voltage direct current (LVDC) distribution grids due to advancements in power electronics enabling efficient and economical electrical networks in the DC paradigm. Power flow equations in LVDC grids are non-linear and non-convex due to the presence of constant power nodes. Depending on the implementation, power flow equations may lead to more than one solution and unrealistic solutions; therefore, the uniqueness of the solution should not be taken for granted. This paper proposes a new power flow solver based on a graph theory for LVDC grids having radial or meshed configurations. The solver provides a unique solution. Two test feeders composed of 33 nodes and 69 nodes are considered to validate the effectiveness of the proposed method. The proposed method is compared with a fixed-point methodology called direct load flow (DLF) having a mathematical formulation equivalent to a backward forward sweep (BFS) class of solvers in the case of radial distribution networks but that can handle meshed networks more easily thanks to the use of connectivity matrices. In addition, the convergence and uniqueness of the solution is demonstrated using a Banach fixed-point theorem. The performance of the proposed method is tested for different loading conditions. The results show that the proposed method is robust and has fast convergence characteristics even with high loading conditions. All simulations are carried out in MATLAB 2020b software.


2018 ◽  
Vol 9 ◽  
pp. 1623-1628 ◽  
Author(s):  
Jonathan Op de Beeck ◽  
Nouha Labyedh ◽  
Alfonso Sepúlveda ◽  
Valentina Spampinato ◽  
Alexis Franquet ◽  
...  

The continuous demand for improved performance in energy storage is driving the evolution of Li-ion battery technology toward emerging battery architectures such as 3D all-solid-state microbatteries (ASB). Being based on solid-state ionic processes in thin films, these new energy storage devices require adequate materials analysis techniques to study ionic and electronic phenomena. This is key to facilitate their commercial introduction. For example, in the case of cathode materials, structural, electrical and chemical information must be probed at the nanoscale and in the same area, to identify the ionic processes occurring inside each individual layer and understand the impact on the entire battery cell. In this work, we pursue this objective by using two well established nanoscale analysis techniques namely conductive atomic force microscopy (C-AFM) and secondary ion mass spectrometry (SIMS). We present a platform to study Li-ion composites with nanometer resolution that allows one to sense a multitude of key characteristics including structural, electrical and chemical information. First, we demonstrate the capability of a biased AFM tip to perform field-induced ionic migration in thin (cathode) films and its diagnosis through the observation of the local resistance change. The latter is ascribed to the internal rearrangement of Li-ions under the effect of a strong and localized electric field. Second, the combination of C-AFM and SIMS is used to correlate electrical conductivity and local chemistry in different cathodes for application in ASB. Finally, a promising starting point towards quantitative electrochemical information starting from C-AFM is indicated.


Sign in / Sign up

Export Citation Format

Share Document