Dynamic simulation for integrated energy systems based on multi-step characteristics method

Dynamic simulation is a meaningful way to study the operation characteristics of the integrated energy system (IES) combined with electric, natural gas (NG), and heat systems. The dynamic processes of NG and heat systems are heavily affected by the pipeline length. However, in practical applications, the length of different pipelines varies greatly. If the unified simulation step is adopted, it is difficult to balance the accuracy and the efficiency of the simulation. To handle the above problem, a dynamic model of IES based on the multi-step characteristics method is proposed. The characteristics method which needs a small simulation step can avoid numerical dispersion. The proposed multi-step algorithm can greatly reduce the simulation calculation and improve the simulation efficiency by selecting the simulation steps appropriate to the pipeline length. Then the dynamic models of coupling devices, including the gas turbine, heat exchanger, and other energy equipment are built to reflect the coupling characteristics of different energy systems. And a multi-rate algorithm is proposed for IES simulation. Case studies verify that the proposed method can effectively improve the simulation efficiency on the premise of ensuring the simulation accuracy.