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Distributed integrated multi-energy systems (DIMSs) can be regarded as virtual power plants to provide additional flexibility to the power system. This paper proposes a robust active dynamic aggregation model for the DIMSs to describe the maximum feasible region. The aggregation model includes the power constraints, energy constraints, and ramping constraints to aggregate different types of resources in the DIMSs. The proposed generator-like and storage-like model does not depend on the ancillary service market and can be directly incorporated into the economic dispatch model of the power system. A novel algorithm based on the column-and-constraint generation algorithm and convex-concave procedure is proposed to solve the two-stage robust optimization problem, which is more efficient than the KKT-based algorithms. Finally, a case study of an actual DIMS is developed to demonstrate the effectiveness of the proposed model.

Multi-energy virtual power plants intend to aggregate multi-energy distributed resources and provide ancillary service to the power system. To exploit more flexibility of the synergy of multi-energy, multiple types of energy conversion equipment and thermal inertia of the commercial buildings are considered in this paper. A capacity limitation service model based on multi-parametric programming is proposed to overcome the difficulty that the power of the demand side distributed resources is difficult to be accurately controlled. Case studies based on an actual multi-energy industrial park in Beijing are conducted to validate the effectiveness of the proposed model.

Gas-steam combined cycle can greatly improve energy efficiency when it is used in cogeneration, and its combustion products are pollution-free. Therefore gas-steam combined cycle has been widely used in recent years. In the present paper, the nonlinear mathematical models of different equipment in an energy station are established, including gas turbines, waste heat boilers, steam turbines and gas boilers. Then the objective function and constraints of economic optimization model are proposed. In order to solve the nonlinear optimization model more efficiently, equipment models are linearized. Finally, the commercial solver CPLEX is used to solve the optimization problem. A case study is given based on an real energy station to illustrate the economic operation results.

The gas and steam combined cycle uses natural gas and realizes the supply of cold, heat and power based on the principle of energy cascade utilization. It has the advantages of high energy efficiency and less pollutant emission, so its application scale is extending. In this paper, the mathematical models of equipment in the energy station, which consists of gas and steam combined cycle, are established. Then the objective function and constraint conditions for multi-objective optimization considering economic and environmental benefits are proposed. The Nash negotiation method is used to find the solution to this multi-objective optimization problem on the Pareto frontier. Since the device models are properly linearized, each sub-problem on the Pareto front becomes a MILP problem, which can be solved by commercial solvers. Finally, a case study based on an actual energy station is carried out and the results of single-objective optimization and multi-objective optimization are compared to illustrate the Pareto effectiveness of the Nash Bargain solution.

This paper proposes a model for the aggregation problem of a multi-energy virtual power plant participating in day-ahead energy markets. The virtual power plant comprises various multi-energy conversion equipment, renewable units and energy storage. The proposed model considers the uncertainty associated with the dispatch signals from the system operator. The resulting model is heuristically modified by solving a series of robust optimization problem to guarantee any possible dispatch signals which satisfy the proposed model can be realized. Results from a case study illustrate the effectiveness of the proposed approach.

A steady-state model that considers thermodynamic properties and the topology of the combined cooling heat and power energy stations is presented. This model, based on components, can describe the relationship between the heat, cold and electricity output and the gas consumed of an energy station more accurately. The components conclude two typical forms of trigeneration, combined cycle gas turbine and internal combustion engine with gas-fired chillers are introduced. The proposed model considers both the thermal characteristics and the topology of the components of the energy station. Several test cases of energy stations based on the former two types of trigeneration demonstrate the accuracy of this model.