What the inverter needs to do
The winning inverter will be the one that achieves the highest power density and meeting a list of other specifications, as determined by a panel of judges, while undergoing testing for 100 hours.
In brief, the other specifications are :
- Must be able to handle up to 2 kVA loads
- Must achieve a power density of equal to or greater than 50 W/in3
- Must be able to handle loads with power factors from 0.7–1, leading and lagging in an islanded mode
- Must be in a rectangular metal enclosure of no more than 40 in3
- Will be taking in 450 V DC power in series with a 10 Ω resistor
- Must output 240 V, 60 Hz AC single phase power
- Must have a total harmonic distortion + noise on both voltage and current of < 5%
- Must have an input ripple current of < 20%
- Must have an input ripple voltage of < 3%
- Must have a DC-AC efficiency of greater than 95%
- Must maintain a temperature of no more than 60°C during operation everywhere on the outside of the device that can be touched.
- Must conform to Electromagnetic Compliance standards as set out in FCC Part 15 B
- Can not use any external source of cooling (e.g. water) other than air
- Does not require galvanic isolation
Our testing philosophy is to not look inside the box. You provide us with a box that has 5 wires coming out of it: two DC inputs, two AC outputs and grounding connection and we only monitor what goes into and comes out of those wires, along with the temperature of the outside of your box, over the course of 100 hours of testing. The inverter will be operating in an islanded more—that is, not tied or synced to an external grid. The loads will be dynamically changing throughout the course of the testing, similar to what you may expect to see in a residential setting.