Sliding mode control of a DC distributed solar microgrid

This paper proposes a standalone distributed photovoltaic system which includes two independently controlled solar power sources, a battery storage and a resistive load. Each of the PV panels consist of cascaded DC-DC boost converters controlled through two independent sliding mode controllers. The design and simulation of the supervisory controller are also discussed. First, maximum power point tracking (MPPT) control strategy is introduced to maximize the simultaneous energy harvesting from both renewable sources. Then, according to the power generation available at each renewable source and the state of charge in the battery, four contingencies will be considered in the supervisory controller. Moreover, power converters interfacing the source and common DC bus will be controlled as voltage sources under a Pi-sliding mode controller. Numerical simulations demonstrate accurate operation of the supervisory controller and functionality of the MPPT algorithm in each operating condition.