scholarly journals Modern Solutions to Modeling and Optimization of the Steady State of Multi-Energy Systems

2020 ◽  
Vol 209 ◽  
pp. 02007
Author(s):  
Dmitry Bykov ◽  
Dmitry Efimov
Keyword(s):  
Steady State ◽  
Mathematical Models ◽  
Optimization Problems ◽  
General Structure ◽  
Flow Distribution ◽  
Energy Systems ◽  
Physical Nature ◽  
Energy System ◽  
Operating Conditions ◽  
Term Operation

A complex solution of problem of creating mathematical models of multi-energy systems is possible using a unified approach. An approach that will ensure consistent construction of mathematical models and unification of computational algorithms. The paper presents the elements of the concept of energy circuits as a basis for unified modeling of systems of different physical nature. The existing and developed approaches to solving the problems of calculating the flow distribution in multi-energy systems are presented, based on the analysis of publications on this subject. The general structure of the mathematical model of the flow distribution in a multi-energy system and the set of optimization problems for steady-state operating conditions are described. A possible formulation of the optimization problem for the short-term operation of a multi-energy system is presented.

Long-Term Degradation-Based Modeling and Optimization Framework

2018 ◽  
pp. 192-220
Author(s):  
Tarannom Parhizkar
Keyword(s):  
Energy Systems ◽  
Optimization Procedure ◽  
Energy System ◽  
Operating Conditions ◽  
Energy Prices ◽  
Ambient Conditions ◽  
Term Operation ◽  
Optimization Framework ◽  
Degradation Models

Energy systems degrade during long-term operation. Thus, performance profile of the system deteriorates over time. To optimize energy system parameters more reliably and accurately, it is necessary to consider degradation models of the system in the optimization procedure. In this chapter, a novel degradation-based optimization framework is proposed. This framework optimizes design and operation parameters of energy systems while accounting for the degradation effects on system performance. Therefore, this framework is beneficial for long-term analysis and optimization of energy systems. Validity and usefulness of the proposed methodology are demonstrated by optimizing the operating conditions and maintenance intervals of a gas turbine power plant, under different seasonal ambient conditions and energy prices. The case study results effectively meet all the positive expectations that are placed on the proposed degradation-based optimization framework.

scholarly journals Development of the methodological basis of the simulation modelling of the multi-energy systems

2019 ◽  
Vol 124 ◽  
pp. 01049 ◽  
Author(s):  
K. Suslov ◽  
V. Piskunova ◽  
D. Gerasimov ◽  
E. Ukolova ◽  
A. Akhmetshin ◽  
...  
Keyword(s):  
Mathematical Models ◽  
Methodological Approach ◽  
Energy Systems ◽  
Physical Nature ◽  
Energy System ◽  
Main Task ◽  
Monitoring And Control ◽  
Methodological Basis ◽  
Advantages And Disadvantages ◽  
Technical Systems

The most modern technical systems are an integration of various energy converters and sources of various physical nature. Mechanical, thermal, electromagnetic, as well as computer (information) monitoring and control system. Multi-energy systems (MES) also belong to the class of such technical devices. The main task in creating mathematical models is a methodological approach that allows joint modelling of 6 energy objects of various nature on a single methodological basis. The article considers the main approaches to the mathematical description of MES, as well as the assumptions and stages of formation for modelling this class of technical systems. The main advantages and disadvantages of the proposed methods for creating mathematical models are considered taking into account the possibility of using optimization methods and using the above models as digital twins for control systems. In addition, the article will present a methodological approach to the formation of mathematical models of an integrated energy system based on the concept of an energy hub using MATLAB.

scholarly journals Power Flow Optimization Problems for Multi-Energy Systems

2021 ◽  
Vol 289 ◽  
pp. 03001
Author(s):  
Dmitry Bykov ◽  
Dmitry Efimov
Keyword(s):  
Degrees Of Freedom ◽  
Optimization Problems ◽  
Flow Distribution ◽  
Energy Systems ◽  
Minimum Cost ◽  
Energy System ◽  
Distribution Networks ◽  
Primary Energy ◽  
Energy Resources ◽  
Transmission And Distribution

Flow distribution calculation is the determination of the values of the state parameters at the nodes and connections of the system that satisfy the Kirchhoff laws. This calculation is necessary to determine the existence and admissibility of operating states in a multi-energy systems, as well as in singleproduct systems. In addition, it is an essential component of solving the problems of optimization of states in order to ensure the minimum cost of production, transmission and distribution of energy resources. Traditionally, a means of such minimization is the redistribution of the load between sources, consumers and storage of energy resources. As a consequence, this redistribution applies to the elements of transmission and distribution networks. This means are supplemented also by the possibility of converting energy resources from one type to another in multi-energy system. Covering the needs of the end consumer in different types of energy can be provided from different primary energy carriers through the chain (sequence) of their transfer and transformation from one type to another. Such a variety of the ways of energy supply, along with the possibilities of storing (accumulating) energy, pro-vides necessary degrees of freedom for solving states optimization problems.

scholarly journals Robust operation of microgrid energy system under uncertainties and demand response program

2020 ◽  
Vol 17 (2) ◽  
pp. 1005
Author(s):  
Sahar Seyyedeh Barhagh ◽  
Amin Mohammadpour Shotorbani ◽  
Behnam Mohammadi-Ivatloo ◽  
Kazem Zare ◽  
Ali Farzamnia
Keyword(s):  
Power Systems ◽  
Demand Response ◽  
Optimization Problems ◽  
Energy Systems ◽  
Stochastic Scheduling ◽  
Energy System ◽  
Optimization Method ◽  
Operating Conditions ◽  
Mixed Integer ◽  
Demand Response Program

<span>Microgrid energy systems are one of suitable solutions to the available problems in power systems such as energy losses, and resiliency issues. Local generation by these energy systems can reduce the role of the upstream network, which is a challenge in risky conditions. Also, uncertain behavior of electricity consumers and generating units can make the optimization problems sophisticated. So, uncertainty modeling seems to be necessary. In this paper, in order to model the uncertainty of generation of photovoltaic systems, a scenario-based model is used, while the robust optimization method is used to study the uncertainty of load. Moreover, the stochastic scheduling is performed to model the uncertain nature of renewable generation units. Time-of–use rates of demand response program (DRP) is also utilized to improve the system economic performance in different operating conditions. Studied problem is modeled using a mixed-integer linear programming (MILP). The general algebraic modeling system (GAMS) package is used to solve the proposed problem. A sample microgrid is studied and the results with DRP and without DRP are compared. It is shown that same robustness is achieved with a lower increase in the operation cost using DRP.</span>

scholarly journals Development of Complex Energy Systems with Absorption Technology by Combining Elementary Processes

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 495 ◽  
Author(s):  
Kosuke Seki ◽  
Keisuke Takeshita ◽  
Yoshiharu Amano
Keyword(s):  
Alternative Energy ◽  
Energy Systems ◽  
Energy System ◽  
Operating Conditions ◽  
Optimal System ◽  
System Configuration ◽  
Bottom Up ◽  
Elementary Processes ◽  
Minimum Number ◽  
Synthesis Methodology

Optimal design of energy systems ultimately aims to develop a methodology to realize an energy system that utilizes available resources to generate maximum product with minimum components. For this aim, several researches attempt to decide the optimal system configuration as a problem of decomposing each energy system into primitive process elements. Then, they search the optimal combination sequentially from the minimum number of constituent elements. This paper proposes a bottom-up procedure to define and explore configurations by combining elementary processes for energy systems with absorption technology, which is widely applied as a heat driven technology and important for improving system’s energy efficiency and utilizing alternative energy resources. Two examples of application are presented to show the capability of the proposed methodology to find basic configurations that can generate the maximum product. The demonstration shows that the existing absorption systems, which would be calculated based on the experience of designers, could be derived by performing optimization with the synthesis methodology automatically under the simplified/idealized operating conditions. The proposed bottom-up methodology is significant for realizing an optimized absorption system. With this methodology, engineers will be able to predict all possible configurations and identify a simple yet feasible optimal system configuration.

Progressive Filtration of the Induced Effects in Thermoeconomic Diagnosis of Energy Systems

2005 ◽  
Author(s):  
V. Verda ◽  
R. Borchiellini
Keyword(s):  
Heat Recovery ◽  
Energy Systems ◽  
Energy System ◽  
Operating Conditions ◽  
Physical Models ◽  
Linear Functions ◽  
Heat Recovery Steam Generator ◽  
System A ◽  
History Of ◽  
Simple Models

In this paper, the thermoeconomic diagnosis of an energy system is discussed. Several important contributions that make the diagnosis more reliable and practical are introduced. This is obtained through an initial filtration of the effects caused by the dependence of the efficiencies of components on their operating condition. With respect to some previously proposed approaches, simple models are used to achieve this objective. These models are productive models, relating resources and products through linear functions. The drawbacks associated with the use of these simple models are overcome through the use of a technique called the anamnesis, which is the analysis of the case history of a system. A second contribution introduced in this paper is constituted by the analysis of four significant cases of anomalies that can occur in a heat recovery steam generator. Two of them have been obtained by simulating the presence of a single anomaly, each time in a different component. In the other cases, two anomalies have been produced at the same time in two different components. The operating conditions have been obtained by using a simulator, but the effects caused by errors in measurements are taken into account. An analysis has been also performed in order to present the advantages connected with the use of simple productive models, instead of physical models, when measured data are processed.

scholarly journals OPTIMIZATION PROBLEMS OF MATHEMATICAL MODELLING OF A BUILDING AS A UNIFIED HEAT AND POWER SYSTEM

2020 ◽  
Vol 16 (1) ◽  
pp. 156-161
Author(s):  
Yuri Tabunshchikov ◽  
Marianna Brodach
Keyword(s):  
Mathematical Model ◽  
Mathematical Models ◽  
Optimization Problems ◽  
Energy System ◽  
Heat Energy ◽  
Objective Functions ◽  
Outdoor Climate ◽  
Energy Flows ◽  
The Mathematical Model ◽  
The Pontryagin Maximum Principle

The mathematical model of a building as a single heat energy system by the decomposition method is represented by three interconnected mathematical models: the first is a mathematical model of the energy interaction of a building’s shell with an outdoor climate; the second is a mathematical model of energy flows through the shell of a building; the third is a mathematical model of optimal control of energy consumption to ensure the required microclimate. Optimization problems for three mathematical models with objective functions are formulated. Methods for solving these problems are determined on the basis of the calculus of variations and the Pontryagin maximum principle. A method for assessing the skill of an architect and engineer in the design of a building as a single heat energy system is proposed.

Evolutionary Multi-Objective Optimization in Energy Conversion Systems

2011 ◽  
pp. 333-363
Author(s):  
Andrea Toffolo
Keyword(s):  
Energy Conversion ◽  
Optimization Problems ◽  
Energy Systems ◽  
Energy System ◽  
Research Field ◽  
Future Research ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Pareto Optimal Set ◽  
Energy Conversion Systems

The research field on energy conversion systems presents a large variety of multi-objective optimization problems that can be solved taking full advantage of the features of evolutionary algorithms. In fact, design and operation of energy systems can be considered in several different perspectives (e.g., performance, efficiency, costs, environmental aspects). This results in a number of objective functions that should be simultaneously optimized, and the knowledge of the Pareto optimal set of solutions is of fundamental importance to the decision maker. This chapter proposes a brief survey of typical applications at different levels, ranging from the design of component detail to the challenge about the synthesis of the configuration of complex energy conversion systems. For sake of simplicity, the proposed examples are grouped into three main categories: design of components/component details, design of overall energy system, operation of energy systems. Each multi-objective optimization problem is presented with a short background and some details about the formulation. Future research directions in the field of energy systems are also discussed at the end of the chapter.

Optimization Models and Methods Developed at the Energy Systems Institute

2013 ◽  
Vol 2 (4) ◽  
pp. 1-15 ◽  
Author(s):  
N.I. Voropai ◽  
V.I. Zorkaltsev
Keyword(s):  
Lagrange Function ◽  
Flow Distribution ◽  
Energy Systems ◽  
Optimization Methods ◽  
Energy System ◽  
General Idea ◽  
Optimization Models ◽  
Hydraulic Systems ◽  
Reduced Gradient Method ◽  
Reduced Gradient

The paper presents shortly some optimization models of energy system operation and expansion that have been created at the Energy Systems Institute of the Siberian Branch of the Russian Academy of Sciences. Consideration is given to the optimization models of energy development in Russia, a software package intended for analysis of power system reliability, and model of flow distribution in hydraulic systems. A general idea of the optimization methods developed at the Energy Systems Institute is given including the reduced gradient method, interior point algorithms, method of modified Lagrange function, and cutting-plane algorithms.

Experimental Study of the Effect of Hydrogen Inflow on Passive Core Cooling System With Natural Circulation Flow

2020 ◽  
Author(s):  
Yasunori Yamamoto ◽  
Masayoshi Mori ◽  
Kosuke Ono ◽  
Tetsuya Takada
Keyword(s):  
Steady State ◽  
Cooling System ◽  
Natural Circulation ◽  
Operating Conditions ◽  
Quasi Steady State ◽  
Circulation Flow ◽  
Term Operation ◽  
Accident Conditions ◽  
Core Cooling

Abstract Isolation Condenser (IC) is one of the passive core cooling systems with natural circulation flow, which is effective for safety measures against station black out. Once core uncover occurs, hydrogen generated in the core affects operating condition of ICs. To use ICs as an important safety measure not only for transient conditions but also for accident conditions, robustness of ICs against hydrogen inflow must be understood well. In this study, experiments with high pressure steam were conducted using experimental setup simulating IC, where helium was injected to simulate hydrogen effects. When the pressure in an accumulator increased high enough, natural circulation flow generated in the experimental loop. After the long-term operation, the pressure and the natural circulation flow rate achieved nearly constant. The pressure at quasi-steady state increased with increasing the helium injection amount. The pressure difference in a section including outlet side of a vertical pipe was slightly increased when helium was injected which may have indicated that the helium accumulated in the section and caused increment of the pressure loss. The startup pressure of the IC simulator also increased when helium was injected, where the driving force by the water head difference also decreased. Though long-term operations were performed after helium injection, the effect of injected helium on operating conditions of the IC remained for quasi-steady state conditions.

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