Hierarchical Optimal Scheduling With Dynamic Correction of Micro-grid Combined Heat and Power

Micro-grid combined heat and power (MCHP) has high efficiency to supply thermal and electrical energy, and it can realize the cascade energy utilization as well as improve the utilization rate of renewable energy. In this paper, an optimal hierarchical scheduling strategy was proposed to realize economical and stable operation of the MCHP. A dynamic feedback correction method was put forward to avoid the mechanical equipment frequent switching between start-up and stop state in the short-term scheduling. An attached penalty cost method was adopted to reduce the power deviation caused by the random fluctuation of renewable energy and load with different time intervals in the ultra-short-term scheduling. The two scheduling with different time intervals were effectively connected by taking the optimization results of the short-term scheduling as the constraint on the ultra-short-term scheduling. A simulation case on the MCHP scheduling was done and the results showed that the proposed methods avoid frequent switching between start-up and stop states of the micro gas turbine (MGT). In addition, the operation time and the fuel consumption of the MGT were greatly decreased. Moreover, the battery and the MGT were adjusted reasonably to improve the utilization rate of renewable energy and achieve economic operation with the premise of energy balance of the MCHP. © 2022 Chin. Soc. for Elec. Eng.