Combined source-effect of photovoltaic generator and bi-directional dc–dc battery charger on inverter control dynamics

Abstract

This study presents a method to solve the dynamic model of a grid-connected photovoltaic (PV) inverter with battery energy storage. A three-phase grid-connected solar-battery system is studied using small-signal state-space modelling in the synchronously rotating dq-reference frame. The combined effect of a PV generator and a bi-directional dc–dc battery charger (BC) on the inverter dynamic behaviour is analysed. It is shown that the characteristic right-half-plane pole in the PV inverter's dc-link voltage control dynamics shifts to a lower frequency when the BC is connected, which improves the stability of the system and allows a lower bandwidth for the dc-link voltage control.

Keywords

• invertors
• dc-dc power convertors
• battery chargers
• power grids
• voltage control
• photovoltaic power systems
• pv generator
• bi-directional dc–dc battery charger
• inverter dynamic behaviour
• pv inverter
• combined source-effect
• photovoltaic generator
• inverter control dynamics
• dynamic model
• grid-connected photovoltaic inverter
• battery energy storage
• three-phase grid-connected solar-battery system
• small-signal state-space modelling
• dc-link voltage control dynamics
• synchronously rotating dq-reference frame