scholarly journals Economic Dispatch of BESS and Renewable Generators in DC Microgrids Using Voltage-Dependent Load Models

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4494 ◽  
Author(s):  
Oscar Danilo Montoya ◽  
Walter Gil-González ◽  
Luis Grisales-Noreña ◽  
César Orozco-Henao ◽  
Federico Serra
Keyword(s):  
Operating Conditions ◽  
Load Model ◽  
Optimal Dispatch ◽  
Load Models ◽  
General Algebraic Modeling System ◽  
Voltage Dependent ◽  
Battery Energy Storage Systems ◽  
Short Term Prediction ◽  
Battery Energy ◽  
The Cost

This paper addresses the optimal dispatch problem for battery energy storage systems (BESSs) in direct current (DC) mode for an operational period of 24 h. The problem is represented by a nonlinear programming (NLP) model that was formulated using an exponential voltage-dependent load model, which is the main contribution of this paper. An artificial neural network was employed for the short-term prediction of available renewable energy from wind and photovoltaic sources. The NLP model was solved by using the general algebraic modeling system (GAMS) to implement a 30-node test feeder composed of four renewable generators and three batteries. Simulation results demonstrate that the cost reduction for a daily operation is drastically affected by the operating conditions of the BESS, as well as the type of load model used.

Analysis on Load Model for Cost Optimization Using Embedded Meta EP-Firefly Algorithm for DG Installation

2015 ◽  
Vol 793 ◽  
pp. 478-482
Author(s):  
S.R.A. Rahim ◽  
Ismail Musirin ◽  
Muhammad Murtadha Othman ◽  
Muhamad Hatta Hussain
Keyword(s):  
Distributed Generation ◽  
Distribution System ◽  
Firefly Algorithm ◽  
Cost Optimization ◽  
Load Model ◽  
Load Models ◽  
Generation Planning ◽  
Voltage Dependent ◽  
The Cost

This paper presents the analysis on load models for cost optimization for distributed generation planning. The Embedded Meta EP – Firefly Algorithm technique is performed in order to identify the optimal distributed generation sizing. The result obtained show that the proposed technique has an acceptable performance to simulate the data and voltage dependent load models have a significant effect on total losses of a distribution system consequently will affect the cost of the system.

scholarly journals Influence of Load Dynamics on Converter-Dominated Isolated Power Systems

2021 ◽  
Vol 11 (5) ◽  
pp. 2341
Author(s):  
José Gouveia ◽  
Carlos L. Moreira ◽  
João A. Peças Lopes
Keyword(s):  
Power Systems ◽  
Control Strategies ◽  
Power Converter ◽  
Operating Conditions ◽  
Load Models ◽  
Successful Recovery ◽  
Battery Energy Storage Systems ◽  
Negative Impacts ◽  
Battery Energy ◽  
Network Fault

The operation of isolated power systems with 100% converter-based generation requires the integration of battery energy storage systems (BESS) using grid-forming-type power converters. Under these operating conditions, load dynamics influences the network frequency and voltage following large voltage disturbances. In this sense, the inclusion of induction motor (IM) load models is required to be properly considered in BESS power converter sizing. Thus, this paper presents an extensive sensitivity analysis, demonstrating how load modeling affects the BESS power converter capacity when adopting conventional control strategies while aiming to assure the successful recovery of all IM loads following a network fault. Furthermore, this work highlights that generators with converter interfaces can actively contribute to mitigate the negative impacts resulting from IM loads following a network fault. Thereby, two distinct control strategies are proposed to be integrated in the power electronic interfaces of the available converter-based generators: one to be adopted in grid-following converters and another one suitable for grid-forming converters. The proposed control strategies provide an important contribution to consolidating insular grid codes, aiming to achieve operational scenarios accommodating 100% penetration of converter-based generation with a significative percentage of the IM load composition without resorting to a significative increase in BESS power converter sizing.

scholarly journals Optimal Location-Reallocation of Battery Energy Storage Systems in DC Microgrids

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2289 ◽  
Author(s):  
Oscar Danilo Montoya ◽  
Walter Gil-González ◽  
Edwin Rivas-Trujillo
Keyword(s):  
Energy Storage ◽  
Storage Systems ◽  
Optimal Location ◽  
Mixed Integer ◽  
Energy Storage Systems ◽  
Battery Energy Storage ◽  
Dc Microgrids ◽  
General Algebraic Modeling System ◽  
Battery Energy Storage Systems ◽  
Battery Energy

This paper deals with the problem of optimal location and reallocation of battery energy storage systems (BESS) in direct current (dc) microgrids with constant power loads. The optimization model that represents this problem is formulated with two objective functions. The first model corresponds to the minimization of the total daily cost of buying energy in the spot market by conventional generators and the second to the minimization of the costs of the daily energy losses in all branches of the network. Both the models are constrained by classical nonlinear power flow equations, distributed generation capabilities, and voltage regulation, among others. These formulations generate a nonlinear mixed-integer programming (MINLP) model that requires special methods to be solved. A dc microgrid composed of 21-nodes with existing BESS is used for validating the proposed mathematical formula. This system allows to identify the optimal location or reallocation points for these batteries by improving the daily operative costs regarding the base cases. All the simulations are conducted via the general algebraic modeling system, widely known as the General Algebraic Modeling System (GAMS).

Can Photovoltaic Battery Energy Storage Systems Be Self-Balancing?

2016 ◽  
Author(s):  
Partha P. Mishra ◽  
Hosam K. Fathy
Keyword(s):  
State Of Charge ◽  
Lyapunov Analysis ◽  
Hybrid Cells ◽  
Battery Energy Storage ◽  
Local Linearization ◽  
Feedback Path ◽  
Novel Approach ◽  
Battery Energy Storage Systems ◽  
Battery Energy ◽  
The Cost

This paper proposes a novel approach for integrating battery storage into photovoltaic (PV) arrays. The approach relies on the integration of PV arrays with individual batteries to form “hybrid cells” that are then assembled into series strings. We use Lyapunov analysis to show that the proposed hybrid strings are globally asymptotically self-balancing, meaning that initial variations in state of charge (SOC), no matter how large, converge to zero. The PV subsystem serves as a negative feedback path that guarantees self-balancing without requiring dedicated balancing circuits. This significantly reduces the cost of the power electronics needed for integrating batteries into PV farms, compared to typical integration topologies. The paper uses local linearization to approximate the balancing rate, thereby highlighting its independence of battery pack length and elucidating its dependence on subsystem sizing. Finally, a simulation study validates the paper’s theoretical insights regarding self-balancing, and examines its sensitivity to parameter heterogeneities.

scholarly journals Optimal Configuration with Capacity Analysis of PV-Plus-BESS for Behind-the-Meter Application

2021 ◽  
Vol 11 (17) ◽  
pp. 7851
Author(s):  
Cheng-Yu Peng ◽  
Cheng-Chien Kuo ◽  
Chih-Ta Tsai
Keyword(s):  
Capacity Allocation ◽  
Electricity Price ◽  
System Capacity ◽  
Pv System ◽  
Pv Systems ◽  
Benefit Evaluation ◽  
Cost Of Energy ◽  
Battery Energy Storage Systems ◽  
Battery Energy ◽  
The Cost

As the cost of photovoltaic (PV) systems and battery energy storage systems (BESS) decreases, PV-plus-BESS applied to behind-the-meter (BTM) market has grown rapidly in recent years. With user time of use rates (TOU) for charging and discharging schedule, it can effectively reduce the electricity expense of users. This research uses the contract capacity of an actual industrial user of 7.5 MW as a research case, and simulates a PV/BESS techno-economic scheme through the HOMER Grid software. Under the condition that the electricity demand is met and the PV power generation is fully used, the aim is to find the most economical PV/BESS capacity allocation and optimal contract capacity scheme. According to the load demand and the electricity price, the analysis shows that the PV system capacity is 8.25 MWp, the BESS capacity is 1.25 MW/3.195 MWh, and the contract capacity can be reduced to 6 MW. The benefits for the economical solution are compared as follows: 20-year project benefit, levelized cost of energy (LCOE), the net present cost (NPC), the internal rate of return (IRR), the return on investment (ROI), discounted payback, total electricity savings, renewable fraction (RF), and the excess electricity fraction. Finally, the sensitivity analysis of the global horizontal irradiation, electricity price, key component cost, and real interest rate will be carried out with the most economical solution by analyzing the impacts and evaluating the economic evaluation indicators. The analysis method of this research can be applied to other utility users to program the economic benefit evaluation of PV/BESS, especially an example for Taiwan’s electricity prices at low levels in the world.

scholarly journals Assessment of Battery Storage Technologies for a Turkish Power Network

2019 ◽  
Vol 11 (13) ◽  
pp. 3669 ◽  
Author(s):  
Mustafa Cagatay Kocer ◽  
Ceyhun Cengiz ◽  
Mehmet Gezer ◽  
Doruk Gunes ◽  
Mehmet Aytac Cinar ◽  
...  
Keyword(s):  
Energy Demand ◽  
Clean Energy ◽  
Power Network ◽  
Renewable Energy Resources ◽  
Battery Energy Storage Systems ◽  
High Investment ◽  
Clean Energy Source ◽  
Battery Energy ◽  
Storage Technologies ◽  
The Cost

Population growth has brought an increase in energy demand and cost that has a meaningful impact on personal and government expenses. In this respect, governments attach importance to investments in renewable energy resources (RER), which are a sustainable and clean energy source. However, the unpredictable characteristics of RER are a major problem for these clean sources and RER need auxiliary assets. Battery energy storage systems (BESS) are one of the promising solutions for these issues. Due to the high investment cost of BESS, governments act cautiously about accepting and implementing BESS in their power network. Recently, with the improvement of technology, the cost of BESS has been reduced, and therefore battery technologies have begun to be applied to conventional systems. In this study, first, we will review and discuss the current globally state-of-the-art BESS and their applications. Later, attention will be turned to a country-specific study for Turkey.

scholarly journals Effect of Load Model Using Ranking Identification Technique for Multi Type DG Incorporating Embedded Meta EP-Firefly Algorithm

2018 ◽  
Vol 150 ◽  
pp. 01014
Author(s):  
Siti Rafidah Abdul Rahim ◽  
Ismail Musirin ◽  
Muhammad Murtadha Othman ◽  
Muhamad Hatta Hussain
Keyword(s):  
Power System ◽  
Distributed Generation ◽  
Distribution System ◽  
Firefly Algorithm ◽  
Optimal Allocation ◽  
Load Factor ◽  
Load Model ◽  
Load Models ◽  
Voltage Dependent ◽  
Identification Technique

This paper presents the effect of load model prior to the distributed generation (DG) planning in distribution system. In achieving optimal allocation and placement of DG, a ranking identification technique was proposed in order to study the DG planning using pre-developed Embedded Meta Evolutionary Programming–Firefly Algorithm. The aim of this study is to analyze the effect of different type of DG in order to reduce the total losses considering load factor. To realize the effectiveness of the proposed technique, the IEEE 33 bus test systems was utilized as the test specimen. In this study, the proposed techniques were used to determine the DG sizing and the suitable location for DG planning. The results produced are utilized for the optimization process of DG for the benefit of power system operators and planners in the utility. The power system planner can choose the suitable size and location from the result obtained in this study with the appropriate company’s budget. The modeling of voltage dependent loads has been presented and the results show the voltage dependent load models have a significant effect on total losses of a distribution system for different DG type.

CAD Of Anticorrosive Protection Of Steel Structures

2019 ◽  
pp. 18-23
Keyword(s):  
Protective Coating ◽  
Computer Aided Design ◽  
Steel Structures ◽  
Cost Effective ◽  
Operating Conditions ◽  
Computational Tool ◽  
Protection Method ◽  
Cost Effective Method ◽  
The Cost ◽  
Aided Design

The choice of cost-effective method of anticorrosive protection of steel structures is an urgent and time consuming task, considering the significant number of protection ways, differing from each other in the complex of technological, physical, chemical and economic characteristics. To reduce the complexity of solving this problem, the author proposes a computational tool that can be considered as a subsystem of computer-aided design and used at the stage of variant and detailed design of steel structures. As a criterion of the effectiveness of the anti-corrosion protection method, the cost of the protective coating during the service life is accepted. The analysis of existing methods of steel protection against corrosion is performed, the possibility of their use for the protection of the most common steel structures is established, as well as the estimated period of effective operation of the coating. The developed computational tool makes it possible to choose the best method of protection of steel structures against corrosion, taking into account the operating conditions of the protected structure and the possibility of using a protective coating.

Optimal Placement of FACTS Devices for Voltage Stability Improvement with Economic Consideration Using Firefly Algorithm

2019 ◽  
Vol 14 (1) ◽  
pp. 5-11
Author(s):  
S. Rajasekaran ◽  
S. Muralidharan
Keyword(s):  
Power Systems ◽  
Voltage Stability ◽  
Firefly Algorithm ◽  
Transmission System ◽  
Operating Conditions ◽  
Optimal Placement ◽  
Voltage Collapse ◽  
Facts Devices ◽  
The Cost ◽  
Bus System

Background: Increasing power demand forces the power systems to operate at their maximum operating conditions. This leads the power system into voltage instability and causes voltage collapse. To avoid this problem, FACTS devices have been used in power systems to increase system stability with much reduced economical ratings. To achieve this, the FACTS devices must be placed in exact location. This paper presents Firefly Algorithm (FA) based optimization method to locate these devices of exact rating and least cost in the transmission system. Methods: Thyristor Controlled Series Capacitor (TCSC) and Static Var Compensator (SVC) are the FACTS devices used in the proposed methodology to enhance the voltage stability of power systems. Considering two objectives of enhancing the voltage stability of the transmission system and minimizing the cost of the FACTS devices, the optimal ratings and cost were identified for the devices under consideration using Firefly algorithm as an optimization tool. Also, a model study had been done with four different cases such as normal case, line outage case, generator outage case and overloading case (140%) for IEEE 14,30,57 and 118 bus systems. Results: The optimal locations to install SVC and TCSC in IEEE 14, 30, 57 and 118 bus systems were evaluated with minimal L-indices and cost using the proposed Firefly algorithm. From the results, it could be inferred that the cost of installing TCSC in IEEE bus system is slightly higher than SVC.For showing the superiority of Firefly algorithm, the results were compared with the already published research finding where this problem was solved using Genetic algorithm and Particle Swarm Optimization. It was revealed that the proposed firefly algorithm gives better optimum solution in minimizing the L-index values for IEEE 30 Bus system. Conclusion: The optimal placement, rating and cost of installation of TCSC and SVC in standard IEEE bus systems which enhanced the voltage stability were evaluated in this work. The need of the FACTS devices was also tested during the abnormal cases such as line outage case, generator outage case and overloading case (140%) with the proposed Firefly algorithm. Outputs reveal that the recognized placement of SVC and TCSC reduces the probability of voltage collapse and cost of the devices in the transmission lines. The capability of Firefly algorithm was also ensured by comparing its results with the results of other algorithms.

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