Sensata Technologies recently introduced the Magnum Energy MicroGT 500 inverter. We contacted the company’s renewable products marketing manager Michael Dixon to find out more.
Solar Power World: The release says, “the MicroGT 500 works with or without battery based inverters, and communicates seamlessly with Magnum Energy battery-based inverters when in AC-coupled mode to taper the battery charge based on battery condition.” What do you mean by battery-based inverter?
Michael Dixon: A battery-based inverter is a bi-directional inverter+ battery charger that serves multiple purposes. It converts DC to AC power, but also allows AC input from multiple power sources so it can augment power from the grid for backup power. It can also charge the battery. To add storage to an existing grid-tie PV inverter installation, the battery-based inverter would be AC coupled to the AC output of a grid-tie inverter, in this case our microinverter.
MicroGT is a 500W microinverter with dual MPPT PV inputs. It is designed for excellent compatibility and seamless operation in AC coupled applications using Magnum off-grid MS-PAE series battery-based inverters/chargers. While many microinverters are connected one-per-panel, the MicroGT supports two PV panels each and is daisy chainable. In a daisy chained connection, the output of one inverter is connected to the inverter next to it instead of connecting to a trunk cable or combiner box. Seven MicroGT inverters can be daisy chained before terminating AC at the combiner/breaker box. This is great advantage over a common trunk cable, because it reduces labor as well as extra parts needed to complete the installation. Dual MPPT inputs also lower installation labor costs, while maintaining independent MPPT for maximum harvest.
Finally, our microinverter communicates with our battery-based inverters, which enables better care and maintenance of the battery. An integrated web-based display shows aspects such as system production and battery state of charge. Because our microinverter is designed to seamlessly integrate with our inverter/charger, customers who wish to add storage will find it easy to upgrade at an affordable price. This combination of features is unique in the market.
SPW: For which type of applications is the microinverter best suited?
MD: The MicroGT is a grid-tied microinverter. Its application is grid interconnected for residential use. It is TROV2, UL1741 and NEC 690.12 compliant for application in all major markets in North America. If the customer opts to add storage, they can now have the benefits of their grid interconnected microinverter plus the benefits of storage and battery backup of their critical loads, all designed to work together.
SPW: The release reads, “This integrated approach to AC coupling is far easier on the battery bank than simple “bang-bang” charging in bulk mode, the method traditional microinverters employ when mated to a non-communicating batter-based inverter.” Can you explain this is more detail?
MD: Protecting batteries from over charging is one of the biggest challenges in AC-coupled systems. This can be addressed in multiple ways via AC relays, DC relays and frequency shift. However, in all of these methods, there are only two states; you either generate power or you don’t. With MicroGT, intelligent communication with the battery-based inverter allows the microinverters to continue to harvest at different power levels, instead of just going between generating power and not. This is not increases battery life, but also increases the overall system yield. For more information on these states see the manual for our related AC Load Diversion Controller.
Michael_M_Mulligan says
Does anyone have a complete solution for a three-phase, off-grid, PV + battery system with a NG generator? [The generator is needed for two reasons: long, dark periods and very high power peaks (40 hp motors).]
MMM
Benjamin Saunders says
I guess there will also be a metering/communications gateway for the Microinverters that the Magnum inverter communicates with?
Benjamin Saunders says
Very interesting. So the inverter, based on battery state of charge, will command the Magnum micro-inverters to throttle back power contribution? Congratulations being the first to market with this technology.