Scalable DC Microgrid Architecture with a One-Way Communication Based Control Interface

In this paper a scalable and controllable dc microgrid architecture has been presented with a source-end to load-end one-way communication based control interface to substantiate efficacious power sharing among five power management units (PMUs) attached to batteries. The system comprises a source converter and a load converter. The source converter consists of a maximum power point tracking (MPPT) controller with a boost average model and the load converter consists of a fanout node and five PMUs. The voltage of the photo voltaic (PV) array is boosted up to 400 V for transmission purpose. Perturb and observation algorithm is used for MPPT implementation. A pulse width modulation (PWM) switched full bridge (FB) converter in the fanout node is constructed to lower the source-end voltage and to generate a fixed intermittent dc bus of 48 V. Buck converter topology is used to design the PMUs and each PMU is controlled in a way to generate an output voltage suitable for a 12 V battery charging application. Sensing the solar irradiance level a one-way communication premise is designed to control the power flow towards and sharing among the PMUs so that the more important units receive more power in a crisis situation. The proposed framework has been tested in MATLAB/Simulink platform and the performance evaluations yield to system efficiencies of more than 85% for different irradiance levels.