Micro-inverters: Intelligent Energy Management and Utility Grid Interface

UCF researchers are working with a start-up company to develop a new generation of an integrated micro-inverter grid-tied system, or “AC brick”. This AC brick is designed to be married to a photovoltaic (PV) panel, transforming it into a smart AC PV module. This smart AC module includes all features required for grid-interconnection, including grid-synchronization, current wave-shaping, protection, and anti-islanding, as well as data communication. This system definition is inherently modular, and allows the consumer to size and expand the system as their budget permits. It allows maximum power point tracking (MPPT) to be applied to each PV panel individually, effectively maximizing the energy yield of the system. It further eliminates the need for high-voltage DC wiring, DC-fusing, and disconnect, radically reducing installation costs. The removal of DC wiring also makes this system touch-safe whenever the grid is absent, a feature crucial to the safety of installers, servicemen, and firemen.

Flow diagram of grid-tie inverter structureGrid-Tied Inverter Structure. Credit: Issa Batarseh

Grid Interface

The photovoltaic system of the future will be expected to support stand-alone operation in an intentional island. It is also expected to actively support grid-operation by providing reactive power and harmonic compensation, voltage amplitude and frequency stabilization, and peak demand shaving. UCF researchers are developing a new AC-microgrid architecture that would coordinate PV generation, battery systems, plug-in hybrid electric vehicles, secondary backup generation, in addition to smart loads. This AC-microgrid is being designed for on-the-fly configuration, and will be able to synchronize and tie to the distribution utility grid, or create a self-sufficient intentional island. It will have the intelligence to manage generation, energy storage, and load shedding based on local energy consumption patterns as well as tariffs and weather forecasts obtained from a web server. This would maximize the value of this system to urban and remote-area users, as well as for the utilities.

Flow diagram showing new architecture for Smart PV Integration; AC PV modules flowing into main breaker panel and then meter, utility grid, and local loads flow out; a system monitor is optional.

A Paradigm Shift in Smart PV Integration — New Architecture.
Credit: Issa Batarseh

Years of Research: 2006 – Present

Selected Publications