Optimal Profit Operation Strategy of the Network-connected CHP in Open Energy Market

In a completely open energy market, the network-connected combined heat and power system (CHPs) is built in an energy supplying area. After the loads in the area are satisfied, its surplus heat and electricity will be imported to the corresponding heat and electric networks to gain additional profits. A maximum profit controller was proposed in this paper, together with the economic operation strategy. Through the status combination of the heat and electricity export to the network from the CHP or import to the energy supplying area from the network, we establish four profit models for the network-connected CHP and divid the CHP operation curve into several optimizing intervals of a day. Each interval corresponds to a specific profit model. Then, in each interval, we use gray forecasting model combined with least square method to work out the energy prices. Based on these prices, the discrete optimal solution of each interval's profit model can be obtained. Considering ramp rate, we use dynamic programming method to obtain optimal operation strategy in real time. Finally, we send all operation data into historical database as feedback control. Through all the steps above, the network-connected CHP's optimal operation strategy can be obtained with the maximum profit. Also, a demonstration example is conducted with a 1MW network-connected CHP in this paper.