Review: Multi-objective optimization methods and application in energy saving

The problem of distributing gas through a network of pipelines is formulated as a cost minimization subject to nonlinear flow-pressure relations, material balances, and pressure bounds. The solution method is based on piecewise linear approximations of the nonlinear flow-pressure relations. The approximated problem is solved by an extension of the Simplex method. The solution method is tested on real-world data and compared with alternative solution methods.

The gas transmission problem solved by an extension of the simplex algorithm

Occupancy-based demand response and thermal comfort optimization in microgrids with renewable energy sources and energy storage

State-of-the-art generation expansion planning: A review

Solar and wind power generation systems with pumped hydro storage: Review and future perspectives

Multi-objective optimization and decision making for power dispatch of a large-scale integrated energy system with distributed DHCs embedded☆

Coordinated scheduling strategy to optimize conflicting benefits for daily operation of integrated electricity and gas networks

As more and more distributed renewable energy resources connected to electric power grids, the conventional power system evolves into an integrated energy grid (lEG) in order to satisfy various types of energy demands. This paper proposes a model of the coordinated scheduling of energy resources (CSoERs) for distributed district heating and cooling systems (DHCs) in an lEG. The model takes into consideration both the dispatchable grid-connected generators and distributed renewable energy resources, such as wind energy, solar energy and natural gas. The objective is to minimize the operation costs in the lEG in order to satisfy not only the electrical loads but also the heating loads and cooling loads. Furthermore, an energy storage system for heating loads and cooling loads is also developed in the DHCs to improve the operation reliability in the distributed DHCs. Detailed simulation studies are carried out to verify the effectiveness of the CSoERs under two different operation scenarios: grid-connected scenario and stand-alone scenario. Simulation results demonstrate that the performance of the CSoERs contributes to significant energy saving and reliability operation in both grid-connected scenario and standalone scenario in the lEG.

Coordinated scheduling of energy resources for distributed DHCs in an integrated energy grid

This paper develops a many-objective optimization model, which contains objectives representing the interests of the electricity and gas networks, as well as the distributed district heating and cooling units, to coordinate the benefits of all parties participated in the integrated energy system (IES). In order to solve the many-objective optimization model efficiently, an improved objective reduction (IOR) approach is proposed, aiming at acquiring the smallest set of objectives. The IOR approach utilizes the Spearman’s rank correlation coefficient to measure the relationship between objectives based on the Pareto-optimal front captured by the multi-objective group search optimizer with adaptive covariance and Levy flights algorithm, and adopts various strategies to reduce the number of objectives gradually. Simulation studies are conducted on an IES consisting of a modified IEEE 30-bus electricity network and a 15-node gas network. The results show that the many-objective optimization problem is transformed into a bi-objective formulation by the IOR. Furthermore, our approach improves the overall quality of dispatch solutions and alleviates the decision making burden.

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Many-objective optimization for coordinated operation of integrated electricity and gas network

The simulation model is one of the key points affecting the optimal planning and operation of energy hubs (EHs). Since treating the efficiencies of generation units as constants would significantly simplify the calculation, only a simplified model is investigated in most research works. In this paper, aiming at optimizing the capacity configuration of an EH, we present a part-load characteristics-based (PLCB) model, in which the efficiencies of generation units will change with the fluctuating load. Based on the PLCB model, the accuracy of the EH model can be improved. Furthermore, a two-stage planning method is proposed to solve the optimal capacity configuration problem of the EH. Group Search Optimizer (GSO) is used to determine the optimal size in the first stage, and a mathematical programming method is applied to obtain the optimal operation of the EH in the second stage. Comparative studies using the PLCB model and the simplified model are performed to examine the impacts of equipment part-load characteristics on the sizing results. Simulation results indicate that the proposed model appears to have a better economic performance than the simplified model.

https://www.mdpi.com/1996-1073/10/12/1966/pdf

Q. H. Wu

Papers

Multi-objective optimization and decision making for power dispatch of a large-scale integrated energy system with distributed DHCs embedded☆

Coordinated scheduling strategy to optimize conflicting benefits for daily operation of integrated electricity and gas networks

Coordinated scheduling of energy resources for distributed DHCs in an integrated energy grid

Many-objective optimization for coordinated operation of integrated electricity and gas network

Optimal Capacity Configuration for Energy Hubs Considering Part-Load Characteristics of Generation Units