On the other hand, the battery current should also be limited. The lower and upper limits (Ib¯ and Ib¯) depend on VocVoc and RintRint through the following expressions:equation(18)Ib¯=(Voc−Vb¯)RintduringchargingIb¯=(Voc−Vb¯)Rintduringdischarging,where Vb¯ and Vb¯ are the lower and upper limits in the battery bank voltage, respectively.
3. Energy management strategy
The Resminostat management strategy is in charge of commanding the operation of the system with the objective of ensuring the power balance with constraints between the power sources, the batteries, and the load. The power balance in the direct-current bus can be expressed as follows:equation(19)PL=Pw+PPV+PFC+Pb−Ph,PL=Pw+PPV+PFC+Pb−Ph,where PwPw, PPVPPV, PFCPFC, and PbPb the powers supplied to the to the direct-current bus by the turbines, the PV array, the fuel cells, and the batteries, respectively. On the other hand, PLPL is the power required by the load and PhPh is the power consumed by the heater in the reformer. It is assumed exothermic the power converters DC/DC, AC/DC, and DC/AC have constant efficiencies (ηDD=0.95ηDD=0.95 and ηAD=ηDA=0.9ηAD=ηDA=0.9).