scholarly journals Day-Ahead Hierarchical Steady State Optimal Operation for Integrated Energy System Based on Energy Hub

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2765 ◽  
Author(s):  
Yongjie Zhong ◽  
Dongliang Xie ◽  
Suwei Zhai ◽  
Yonghui Sun
Keyword(s):  
Steady State ◽  
Natural Gas ◽  
Energy Demand ◽  
Operating Cost ◽  
Energy System ◽  
Optimal Operation ◽  
Cost Index ◽  
District Heating System ◽  
Energy Hub ◽  
Integrated Energy System

The integrated energy system (IES) has the characteristic of energy system integrated/multi-energy coupling that involves heat, cooling, electricity, natural gas, and various other energy forms, which can maximize the synergistic effects and complementary benefits among various energy forms and their comprehensive utilization. In this paper, based on energy hub (EH), the day-ahead hierarchical steady state optimal operation for IES is discussed, in which the coupling natural gas system, electricity transmission system, and district heating system are all considered. Firstly, the model architecture of EH with diverse storage devices, renewable energy, and different energy conversion equipment is proposed and the steady state mathematical model of different energy networks in IES is developed, respectively. Secondly, the day-ahead operating cost of EH is minimized by an optimizing strategy to maximize the benefits of all kinds of energy demand users, where different types of energy power input into EH can be obtained. Then, the day-ahead optimal operation mode for IES considering minimization of operating fuel cost index is proposed via an energy management system, which provides various energy power data that are uploaded from EH. Finally, numerical results are presented to verify the effectiveness and usefulness of the day-ahead hierarchical optimal operation and steady state calculation analysis for IES, which could further illustrate that the proposed optimal operation can meet the requirements of practical engineering applications.

scholarly journals Optimal Operation of Integrated Electrical and Natural Gas Networks with a Focus on Distributed Energy Hub Systems

2020 ◽  
Vol 12 (20) ◽  
pp. 8320
Author(s):  
Mohammad Hemmati ◽  
Mehdi Abapour ◽  
Behnam Mohammadi-Ivatloo ◽  
Amjad Anvari-Moghaddam
Keyword(s):  
Natural Gas ◽  
Gas Flow ◽  
Energy Systems ◽  
Energy System ◽  
Optimal Operation ◽  
Electrical Load ◽  
Energy Hub ◽  
Proposed Model ◽  
Carrier Energy ◽  
Integrated Energy System

Coordinated multi-carrier energy systems with natural gas and electricity energies provide specific opportunities to improve energy efficiency and flexibility of the energy supply. The interdependency of electricity and natural gas networks faces multiple challenges from power and gas flow in corresponding feeders and pipes and connection points between two infrastructures’ points of view. However, the energy hub concepts as the fundamental concept of multi-carrier energy systems with multiple conversion, storage, and generation facilities can be considered as a connection point between electricity and gas grids. Hence, this paper proposes an optimal operation of coordinated gas and electricity distribution networks by considering interconnected energy hubs. The proposed energy hub is equipped with combined heat and power units, a boiler, battery energy storage, a heat pump, and a gas-fired unit to meet the heating and electrical load demands. The proposed model is formulated as a two-stage scenario-based stochastic model aiming to minimize total operational cost considering wind energy, electrical load, and real-time power price uncertainties. The proposed integrated energy system can participate in real-time and day-ahead power markets, as well as the gas market, to purchase its required energy. The AC-power flow and Weymouth equation are extended to describe power and gas flow in feeders and gas pipelines, respectively. Therefore, a realistic model for the integrated electricity and gas grids considering coupling constraints is satisfied. The proposed model is tested on the integrated energy system and consists of a 33-bus electrical network and a 6-node gas grid with multiple interconnected energy hubs, where the numerical results reveal the effectiveness of the proposed model.

scholarly journals An Energy Optimal Dispatching Model of an Integrated Energy System Based on Uncertain Bilevel Programming

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 477 ◽  
Author(s):  
Xueying Song ◽  
Hongyu Lin ◽  
Gejirifu De ◽  
Hanfang Li ◽  
Xiaoxu Fu ◽  
...  
Keyword(s):  
Objective Function ◽  
Decision Maker ◽  
Bilevel Programming ◽  
Firefly Algorithm ◽  
Operating Cost ◽  
Energy System ◽  
Optimal Operation ◽  
Decision Makers ◽  
Improved Firefly Algorithm ◽  
Integrated Energy System

An integrated energy system (IES) involving a large number of decision-makers causes problems of bad coordination between energy sub-networks and the IES and it is not able to fully consider the multi-energy complementarity among multiple decision-makers. In this context, firstly, this paper constructs an energy optimal dispatching model of an IES based on uncertain bilevel programming. The upper model takes the transformation matrix of energy hubs as the upper decision-maker, taking the minimum operation cost of the IES in the form of confidence as the objective function; the lower model takes each optimal operation plan of the electric power sub-network, the thermal energy sub-network, and the gas energy sub-network as the lower decision-makers, aiming at the operation economy of each sub-network and considering their operation as necessary constraints. Secondly, a firefly algorithm with chaotic search and an improved light intensity coefficient is designed to improve the proposed model. An empirical analysis was conducted on a pilot area of an integrated energy system in Hebei Province. The results show the following: (1) The typical daily operating cost of the integrated energy system in winter is lower than that in summer; (2) under the same load level, the typical winter and summer running costs of the integrated energy system are lower than that of the traditional microgrid; (3) compared with the particle swarm optimization algorithm, the improved firefly algorithm proposed in the paper has obvious advantages both in terms of running cost and solution time; and (4) when the confidence of the objective function and the constraints increases, the operating cost of various schemes also increase. The above results validate the effectiveness of the energy optimal dispatching model of the IES and the economy of the system operation under the multiple decision-maker hierarchy.

scholarly journals Optimal operation of regional integrated energy system based on demand-side load response

2020 ◽  
Vol 213 ◽  
pp. 02005
Author(s):  
Peng Fang ◽  
Cui Mao ◽  
Yuping Chen ◽  
Shan Zhou ◽  
Rui You ◽  
...  
Keyword(s):  
Operating Cost ◽  
Electric Heating ◽  
Energy System ◽  
Optimal Operation ◽  
Energy Utilization ◽  
Utilization Rate ◽  
Demand Side ◽  
Side Load ◽  
Load Response ◽  
Integrated Energy System

The integrated energy system (IES) has the advantage of improving energy utilization and promoting energy flexibility. From the perspective of demand-side load response, this paper establishes demand-side power, thermal load response, and natural gas demand response models, and then constructs the objective function of the lowest operating cost of the regional IES for combined electric heating and gas supply, using Cplex to perform optimization. Finally, a typical northern park is taken as an example to analyze and verify the feasibility of the model and algorithm. The analysis of the case shows that considering the electric heating gas demand side response will be better than not considering or considering only the single and both responses, not only can reduce operating costs, achieve peak reduction and valley filling, but also reduce abandonment of wind and energy, and increase energy utilization rate.

scholarly journals Optimal Operation Of Integrated Energy System Considering Demand Response

2021 ◽  
Vol 2087 (1) ◽  
pp. 012017
Author(s):  
Yan Liang ◽  
Yao Wang ◽  
Hongli Liu ◽  
Peng Wang ◽  
Yongming Jing ◽  
...  
Keyword(s):  
Demand Response ◽  
Operating Cost ◽  
Energy System ◽  
Optimal Operation ◽  
Adaptive Genetic Algorithm ◽  
Load Matching ◽  
Integrated Energy Systems ◽  
Cost Of Energy ◽  
Integrated Energy System ◽  
System Operating

Abstract Due to the high cost of energy storage part in traditional integrated energy systems, the demand response effect is poor. The paper proposes electrolytic water hydrogen production technology and applies it to the optimal operation of integrated energy system. By optimizing the operating cost of the system through adaptive genetic algorithm, we show that when the load matching degree was increased from 50% to 70%, the system operating cost was reduced by about 15.8%, and the carbon displacement was decreased by about 35%. System operating costs, carbon emissions, and the amount of electrolytic water systems involved in the demand response have all decreased.

scholarly journals Steady-State Power Flow Analysis of Cold-Thermal-Electric Integrated Energy System Based on Unified Power Flow Model

Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4455
Author(s):  
Qu ◽  
Ouyang ◽  
Yuan ◽  
Zeng
Keyword(s):  
Steady State ◽  
Water Supply ◽  
Power Flow ◽  
Flow Model ◽  
Flow Analysis ◽  
State Power ◽  
Energy System ◽  
Optimal Operation ◽  
Tight Coupling ◽  
Integrated Energy System

The integrated energy system includes various energy forms, complex operation modes and tight coupling links, which bring challenges to its steady-state modeling and steady-state power flow calculation. In order to study the steady-state characteristics of the integrated energy system, the topological structure of the cold-thermal-electric integrated energy system is given firstly. Then, the steady-state model of the power subsystem, the thermal subsystem, the cold subsystem and the distributed energy station are established, the unified power flow model is established, and the Newton Raphson algorithm is used to solve the unified power flow model. Finally, the influence of the key technical parameters on the steady-state power flow of the integrated energy system is analyzed. Research results show that the photovoltaic power generation plays a supporting role in the voltage of each bus; with the increase of electric load power, the unit value of bus voltage decreases continuously; the water supply temperature of the source node has a greater impact on the steady-state flow in the pipeline and the water supply temperature of each node; the pipeline length of the heat network has a greater impact on the end temperature of the pipeline, the water supply temperature, and the return water temperature of each node. The analysis results can support the planning, design, and optimal operation of the integrated energy system.

scholarly journals Operational optimization of a building-level integrated energy system considering additional potential benefits of energy storage

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Sai Liu ◽  
Cheng Zhou ◽  
Haomin Guo ◽  
Qingxin Shi ◽  
Tiancheng E. Song ◽  
...  
Keyword(s):  
Energy Storage ◽  
Operating Cost ◽  
Economic Cost ◽  
Energy System ◽  
Peak Shaving ◽  
Operational Optimization ◽  
Integrated Energy System ◽  
Potential Benefits ◽  
The Times ◽  
Building Level

AbstractAs a key component of an integrated energy system (IES), energy storage can effectively alleviate the problem of the times between energy production and consumption. Exploiting the benefits of energy storage can improve the competitiveness of multi-energy systems. This paper proposes a method for day-ahead operation optimization of a building-level integrated energy system (BIES) considering additional potential benefits of energy storage. Based on the characteristics of peak-shaving and valley-filling of energy storage, and further consideration of the changes in the system’s load and real-time electricity price, a model of additional potential benefits of energy storage is developed. Aiming at the lowest total operating cost, a bi-level optimal operational model for day-ahead operation of BIES is developed. A case analysis of different dispatch strategies verifies that the addition of the proposed battery scheduling strategy improves economic operation. The results demonstrate that the model can exploit energy storage’s potential, further optimize the power output of BIES and reduce the economic cost.

Regional integrated energy system schemes selection based on risk expectation and Mahalanobis-Taguchi system

2021 ◽  
pp. 1-18
Author(s):  
Jiahang Yuan ◽  
Yun Li ◽  
Xinggang Luo ◽  
Lingfei Li ◽  
Zhongliang Zhang ◽  
...  
Keyword(s):  
Energy Demand ◽  
Choquet Integral ◽  
Subjective Evaluation ◽  
Risk Attitude ◽  
Energy System ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
Energy Structure ◽  
Fuzzy Measures ◽  
Integrated Energy System

Regional integrated energy system (RIES) provides a platform for coupling utilization of multi-energy and makes various energy demand from client possible. The suitable RIES composition scheme will upgrade energy structure and improve integrated energy utilization efficiency. Based on a RIES construction project in Jiangsu province, this paper proposes a new multi criteria decision-making (MCDM) method for the selection of RIES schemes. Because that subjective evaluation on RIES schemes benefit under criteria has uncertainty and hesitancy, intuitionistic trapezoidal fuzzy number (ITFN) which has the better capability to model ill-known quantities is presented. In consideration of risk attitude and interdependency of criteria, a new decision model with risk coefficients, Mahalanobis-Taguchi system and Choquet integral is proposed. Firstly, the decision matrices given by experts are normalized, and then are transformed to minimum expectation matrices according to different risk coefficients. Secondly, the weights of criteria from different experts are calculated by Mahalanobis-Taguchi system. Mobius transformation coefficients based on interaction degree are to calculate 2-order additive fuzzy measures, and then the comprehensive weights of criteria are obtained by fuzzy measures and Choquet integral. Thirdly, based on group decision consensus requirement, the weights of experts are obtained by the maximum entropy and grey correlation. Fourthly, the minimum expectation matrices are aggregated by the intuitionistic trapezoidal fuzzy Bonferroni mean operator. Thus, the ranking result according to the comparison rules using the minimum expectation and the maximum expectation is obtained. Finally, an illustrative example is taken in the present study to make the proposed method comprehensible.

Security region of natural gas network in electricity-gas integrated energy system

2020 ◽  
Vol 117 ◽  
pp. 105601 ◽  
Author(s):  
Xue Li ◽  
Guoda Tian ◽  
Qingxin Shi ◽  
Tao Jiang ◽  
Fangxing Li ◽  
...  
Keyword(s):  
Natural Gas ◽  
Energy System ◽  
Gas Network ◽  
Natural Gas Network ◽  
Integrated Energy System ◽  
Security Region
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