Dynamic modeling of DC nanogrid local branch using enhanced PV and third order battery models

Abstract

Distributed generation via residential branches connected to DC buses are going increased considered an open energy system. These residential branches DC buses have a lot of different shapes forming several types. One of these types is using photovoltaic PV and battery storage system (BSS) connected to main DC bus or multi-terminal DC (MTDC) buses. Recently, this is named DC nanogrid interconnected together forming DC microgrid. In this regard, this paper presents a type of these nanogrid local branch systems (NG-LBS) for residential PV and BSS in detailed modeling and implementing a new assemblage by using enhanced photovoltaic diode model (EPVDM) array, coupled to DC-DC boost converter and maximum power point tracking (MPPT). A novel technique for MPPT is polynomial computational method (PCM) has been used. The BSS has been presented in detailed dynamic model through lead acid battery type by applying third order thevenin equivalent circuit connected in parallel with the single terminal DC (STDC) home load bus. The dynamic behavior for NG-LBS has been shown via dynamic PV with boost converter and PCM MPPT and integrated with the dynamical third order lead acid BSS for charging, discharging and constant charge cases at different radiations and loads.