Economic Evaluation of Micro-Grid System in Commercial Parks Based on Echelon Utilization Batteries

The rapid growth of the air-conditioning load leads to a further increase in the peak-to-valley difference of the load, which has affected the steady operation of the power grid. An economic evaluation method of the controlled air-conditioning load combined echelon utilization batteries in the micro-grid system of a commercial park participating in the demand side management is discussed in this paper. Through the study of the optimal control mode of air-conditioning load groups, taking the user comfort and the fairness of the air-conditioning control into consideration, an orderly control model of the air conditioning is developed by the improved state-queue (ISQ) control algorithm. Echelon utilization batteries are introduced into the micro-grid system of the commercial park, and a coordinated optimization allocation and economic evaluation model of the micro-grid system in the commercial park is established. The particle swarm optimal algorithm (PSO) and the artificial bee colony algorithm (ABC) are employed to solve the model. The simulation tests of the actual operating data in the commercial park in Shanghai of China show that the controlled air-conditioning load can improve the optimal allocation of resources and promote the energy utilization rate by participating in the demand side management. The optimized regulation of the air-conditioning load not only improves the user's comfort but also reduces the cost of the purchasing electricity from the grid. When the purchasing cost of the unit capacity for the echelon utilization batteries is less than 254.5391 USD/kWh, the economy of the echelon utilization batteries is better than the conventional energy storage batteries. The method presented in this paper provides a theoretical basis for the echelon utilization of retired electric vehicle batteries (REVBs) and has certain engineering application prospects.