The CCHP system is the connection between the energy input, that is, the electricity and the fuel, and the building users’ demand. From such a mapping perspective, a CCHP system can be viewed as an energy hub with multiple energy vectors at the input and output terminals. The energy hub represents an interface between different energy infrastructures and/or loads. The coupling of different energy carriers is established by the conversions among them. For instance, the PGU in the CCHP system can generate electricity and thermal energy simultaneously by combusting fuel. The electricity and thermal energy provided by the PGU will...