Integration of dynamic CHPP and gas boiler behaviour into the convex planning problem for the optimised operation of multimodal microgrids

Abstract

Decentralized energy systems like microgrids can be a favourable alternative to the centralized organisation of the current energy supply system. An important problem regarding microgrids is the optimisation of their operational strategy, although most works assume time-independent behaviour of microgrid components in optimisation models. Therefore, the goal of this study is the integration of the dynamic behaviour of a Gas Stirling engine combined heat and power plant and an auxiliary gas boiler in the operational planning problem of a hybrid microgrid. A dynamic optimisation model is developed and compared to a static and approximated model based on the results of three different test scenarios. The simulation results show that the integration of dynamic component characteristics has a significant impact on the operational strategy. The resulting setpoints for the control of the components are able to consider the transient behaviour of these components and therefore their real behaviour is more accurately represented within the optimisation problem. However, the integration of the dynamic modelling approaches leads to more difficult optimisation problems which require more computational effort. The approximation to a convex quadratic problem represents a good compromise between computation time and setpoint accuracy.