Overview
The “Percent differential” element is based on a configurable dual-breakpoint / dual-slope differential restraint characteristic. The purpose of this characteristic is to define the differential/restraint ratio for the transformer winding currents at different loading and fault conditions to securely distinguish between external and internal faults.
For more detailed information on “Percent differential” element, refer to GE, Universal Relay (UR) family of products, Version 8.0x manuals.
To see other supported elements, click here.
Setting Parameters
Modbus memory map for Setting parameters
| Products | Hex address | Register name | Range | Units | Step | Format | Default |
| G30, T35, T60 | 3E65 | Percent Differential Function | 0 to 1 | — | 1 | F102 | 0 (Disabled) |
| " | 3E66 | Percent Differential Pickup | 0.05 to 1 | pu | 0.001 | F001 | 100 |
| " | 3E67 | Percent Differential Slope 1 | 15 to 100 | % | 1 | F001 | 25 |
| " | 3E68 | Percent Differential Break 1 | 1 to 2 | pu | 0.001 | F001 | 2000 |
| " | 3E69 | Percent Differential Break 2 | 2 to 30 | pu | 0.001 | F001 | 8000 |
| " | 3E6A | Percent Differential Slope 2 | 50 to 100 | % | 1 | F001 | 90 |
| " | 3E6B | Inrush Inhibit Function | 0 to 2 | — | 1 | F168 | 1 (Adapt. 2nd) |
| " | 3E6C | Inrush Inhibit Level | 1 to 40 | %fo | 0.1 | F001 | 200 |
| " | 3E6D | Overexcitation Inhibit Function | 0 to 1 | — | 1 | F169 | 0 (Disabled) |
| " | 3E6E | Overexcitation Inhibit Level | 1 to 40 | %fo | 0.1 | F001 | 100 |
| " | 3E6F | Percent Differential Block | 0 to 4294967295 | — | 1 | F300 | 0 |
| " | 3E71 | Percent Differential Target | 0 to 2 | — | 1 | F109 | 0 (Self-reset) |
| " | 3E72 | Percent Differential Events | 0 to 1 | — | 1 | F102 | 0 (Disabled) |
| " | 3E73 | Transformer Inrush Inhibit Mode | 0 to 3 | — | 1 | F189 | 0 (Per phase) |
| F102 | 0 = Disabled, 1 = Enabled | ||||||
| F109 | 0 = Self-reset, 1 = Latched, 2 = Disabled | ||||||
| F168 | 0 = Disabled, 1 = Adapt. 2nd, 2 = Trad. 2nd | ||||||
| F169 | 0 = Disabled, 1 = 5th | ||||||
| F189 | 0 = Per Phase, 1 = 2-out-of-3, 2 = Average, 3 = 1-out-of-3 | ||||||
Logics & highlights
Equations
Phase and zero sequence compensation for typical values of Øcomp
Percent differential calculations
Percent differential operating characteristic
Percent differential logic
