Model Predictive Control of Multi-String PV Systems with Battery Back-Up in a Community DC Microgrid Conference Paper uri icon

abstract

  • © 2017 IEEE. This paper presents the operational control strategy of multi-string photovoltaic (PV) systems in a dc microgrid by using model predictive control (MPC). Due to the intermittent nature of solar energy, battery energy storage system with unify-controlled charger is integrated to the dc microgrid to compensate the fluctuating generated PV power and to regulate the dc-bus voltage. A two-string PV system is considered in this paper to evaluate the performance of the proposed controller. The proposed MPC for the dc microgrid consists: maximum power point tracking (MPPT) of PV arrays and control of a bidirectional dc-dc converter for charging/discharging the battery energy storage system. The controller tracks the maximum power point (MPP) of each PV string under dynamic weather condition and ensures to deliver the required power by the load using the battery system in case of insufficient power generated by the PV systems. The MPC of the battery system stabilizes the bus voltage by considering the state of charge (SoC) of battery and evaluating the direction of power flow from battery system to the dc bus and vice versa. By using the characteristics of MPC with ability to add design constraints, the proposed system ensures power distribution among PV arrays and evaluates the battery SoC for changing the mode of operation to achieve a reliable energy source for the local loads. The practical feasibility of the proposed controller is studied for several case studies and verified experimentally by implementing the controller using dSPACE 1007 platform.

author list (cited authors)

  • Xiao, S., Shadmand, M. B., & Balog, R. S.

citation count

  • 15

publication date

  • March 2017

publisher