Power Management Control Strategy for a Photovoltaic Micro-Inverter with Embedded Hybrid Energy Storage System

A power management control strategy for a photovoltaic micro-inverter with embedded hybrid energy storage system is proposed. The analyses are focused on the performance of the control scheme for feeding a local load. Three levels of control are proposed. Primary control is directly applied to power converters to manage the energy flow based on the reference current tracking. The secondary control oversees regulating the DC Bus voltage by means of the power balance, which ensures that the load power is equal to the power in the DC Bus. The tertiary control is in charge of the system dynamics, that is, it is responsible for responding adequately to sudden changes, in this case, when the load power increase. The primary control includes an input-output linearization control, allowing the use of linear controllers that are not limited to an operating point. A Maximum Power Point Tracking algorithm based on the incremental conductance is implemented on the photovoltaic panel. A suitable control scheme for the hybrid energy storage system is proposed to tracking both, DC link voltaje and AC output voltaje-current, alowing to stabilize the system to sudden changes. Simulated results are presented to validate the properness of the proposed control strategy.