Dynamic Modeling and Stability Control Strategy of Integrated Energy System in Multi-Time Scales

In this article, the overall framework of integrated energy system (IES) is established including the integrated dynamic models of electricity, gas, and heat networks. The operation mechanism, dynamic coupling, energy flow constraints, and multi-time scale coordination of IES are fully considered as the basis of stability control. Then, an innovative multi-time-scale stability control strategy is proposed to simultaneously control the dynamic stability of voltage, frequency, flow, pressure, and temperature based on discrete model predictive control (DMPC). The outputs of outer loop control in long-time scale are regarded as the model inputs and control objectives for the inner loop control in short-time scale. The optimal solutions of electricity, heat, and gas are simultaneously obtained without decoupling based on the established integrated dynamic models. The proposed stability control method simplifies and unifies the stability control mode of different energy forms. Finally, the simulation results demonstrate the proposed scheme can synchronously achieve the control objectives (frequency/voltage/temperature/mass flow/pressure regulation).