# Optimal Operation of CCHP Smart Distribution Grid with Integration of Renewable Energy
###### Abstract  
Recently, electric distribution grids supply not only electric loads but also heating and cooling loads simultaneously to increase the efficiency of the system and reduce the emission of greenhouse gases. An energy management system (EMS) to reduce the combined total expense including environmental damage cost of the combined cooling, heating, and power (CCHP) smart distribution grids in a cooperative framework is proposed in this paper. The entire problem is modelled as a unit commitment interval mixed integer quadratic program (UCIMIQP). The UC is developed to respond to the operation of the electric, heating, and cooling systems and takes into consideration the exchange of energy between these systems. In addition, the demand response (DR) is incorporated with the optimization problem as a decision variable to shave the peak load and reduce the total system cost. The environmental damage is converted to expense, and the entire combined problem is converted to a unified function that is possible to solve in one step, where this is suitable for online operation. Furthermore, a set of realistic constraints is considered to make the approach close to a real scenario. To verify the effectiveness and robustness of the proposed model, the analysis is applied to the distribution grids, which include electrical, heating, and cooling systems, where these systems operated cooperatively. The interaction between these systems makes the operation more flexible and economical. The results show that the total cost is reduced through an exchange in energy between the systems. Additionally, the consideration of the demand response reduces the maximum load and decreases the total cost. CCHP; demand side management; multi-objective optimization; unit commitment; environmental damage cost 2025  
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[PERSON], [PERSON], [PERSON], [PERSON]. The optimal operation of the CCHP achieves significant benefits for both the environment and the system operators. Therefore, many sophisticated and intelligent algorithms have been developed to model and analyze the optimal operation of the CCHP system. Many researchers address different optimization approaches to minimize the operating cost of multicarrier systems. In ref. [1; 2; 3; 4; 5; 6; 7; 8; 9; 10], authors proposed EMS to minimize the total operation cost of systems which supply electric and heat power (CHP). However, the cooling system is not taken into consideration in the approaches proposed in these papers. Authors in reference [11] proposed optimal operation planning of CCHP with the integration of renewable energy. Different cases with and without renewable energy are conducted to evaluate the impacts of wind and solar energy on the optimal operation of the CCHP system. The results showed that the performance of CCHP integrated with either photovoltaic panels or solar collectors is much better than CCHP integrated with photovoltaic thermal solar collectors. A day-ahead optimal planning of the CCHP system with integration of renewable energy resources was presented in [12; 13]. It was found that employing the storage energy device reduces the cost. Authors in reference [14] proposed an EMS of the CCHP system to minimize the operating cost and keep the risk at a permissible level, while reference [15] presented an EMS to minimize the operation cost of the CCHP system with consideration of renewable energy. Reference [16] suggested optimal planning to reduce the operating cost with the integration of renewable energy where the results revealed that the proposed approach improves the system's energy efficiency. References [11; 12; 13; 14; 15; 16] minimized the operating cost only, and they ignored the environmental damage cost in their proposed approaches. In addition, unit commitment was not taken into account in their analysis. Further, many realistic constraints were overridden, and they managed only the generation side and did not consider the management of consumption of end users.