Voltage-trip blind band calculator
For a given under- and over-voltage trip window, which island loads would a voltage trip alone fail to catch?
A teaching aid, not a protection study. Simple model: a resistive island load, an inverter that holds its output current, real power only. The band edges are 1/OV and 1/UV. The 88% and 110% preset matches the 91% to 114% printed in Sandia report SAND2002-3591 (2002). Other presets and the site loads are invented. Real inverters add other detection methods, so a load inside the band is not an undetected island in practice.
| Result | Value |
|---|---|
| Lowest load with no voltage trip (% of inverter output) | - |
| Highest load with no voltage trip (% of inverter output) | - |
| Width of the blind band (percentage points) | - |
| Your load as % of inverter output | - |
| Island voltage (% of nominal) | - |
Method: island voltage as a share of nominal = inverter output divided by load, because the inverter holds its current and the load is a fixed resistance. No voltage trip while UV is at or below that voltage and OV is at or above it. Numbers accept 1,100 or 0,20 style input. "1.000" is rejected as ambiguous.