Coordinated operation of gas-electricity integrated distribution system with multi-CCHP and distributed renewable energy sources

As the increasing penetration of renewable energy sources in distribution network, the tie-line power fluctuation caused by intermittent renewable energy produces a detrimental impact on security and reliability of the main grid. Therefore, maximization of renewable energy utilization as well as stabilization of tie-line power fluctuation are both required in the distribution network, to ease the power regulation burden of main grid. Remarkably, the development of integrated energy systems makes it possible to transfer the fluctuation in power network to other larger inertial systems. This paper proposes a coordinated operation strategy for the gas-electricity integrated distribution system, considering AC power flow in the power network and the gas hydraulic calculation in gas network. In addition, based on the nonlinear multi-energy coupling external characteristics modeling of CCHP system, the power fluctuation of renewable energy sources is transferred to gas distribution network and cooling or heating system by coordinated operation of Multi-CCHPs. Moreover, a two-stage optimization algorithm is proposed to solve the corresponding mixed integer nonlinear programming (MINLP) problem. The simulations conducted on 33-node power distribution network and 24-node gas network show that the proposed method can effectively smooth the tie-line power fluctuation in variety case.