Overview
For more detailed information on “Transient ground fault detection” element, refer to Universal Relay (UR) family of products, Version 8.0x manuals.
To view other supported elements, click here.
Setting Parameters
Modbus memory map for Setting parameters
| Products | Hex address | Register name | Range | Units | Step | Format | Default |
| D60, F35, F60, L90, T35 | CDAA | Transient Ground Fault Detection 1 Function | 0 to 1 | — | 1 | F102 | 0 (Disabled) |
| " | CDAB | Transient Ground Fault Detection 1 Source | 0 to 5 | — | 1 | F167 | 0 (SRC 1) |
| " | CDAC | Transient Ground Fault Detection 1 Voltage | 0 to 1 | — | 1 | F234 | 1 (Measured VX) |
| " | CDAD | Transient Ground Fault Detection 1 Current | 0 to 1 | — | 1 | F235 | 1 (Measured IG) |
| " | CDAE | Transient Ground Fault Detection 1 Pwr Thld | 0 to 100 | W | 0.1 | F001 | 30 |
| " | CDAF | Transient Ground Fault Detection 1 Volt PKP | 0 to 1.5 | pu | 0.01 | F001 | 10 |
| " | CDB0 | Transient Ground Fault Detection 1 Block | 0 to 4294967295 | — | 1 | F300 | 0 |
| " | CDB2 | Transient Ground Fault Detection 1 Target | 0 to 2 | — | 1 | F109 | 0 (Self-reset) |
| " | CDB3 | Transient Ground Fault Detection 1 Events | 0 to 1 | — | 1 | F102 | 0 (Disabled) |
| " | CDB4 | …Repeated for Transient Ground Fault Detection 2 | |||||
| " | CDBE | …Repeated for Transient Ground Fault Detection 3 | |||||
| " | CDC8 | …Repeated for Transient Ground Fault Detection 4 | |||||
| F35 | CDD2 | …Repeated for Transient Ground Fault Detection 5 |
| F102 | 0 = Disabled, 1 = Enabled | ||||||
| F109 | 0 = Self-reset, 1 = Latched, 2 = Disabled | ||||||
| F167 | 0 = SRC 1, 1 = SRC 2, 2 = SRC 3, 3 = SRC 4, 4 = SRC 5, 5 = SRC 6 | ||||||
| F234 | 0 = Calculated VN, 1 = Measured VX | ||||||
| F235 | 0 = Calculated IN, 1 = Measured IG | ||||||
| F300 | 0 : Off (This is boolean FALSE value), 1 : On (This is boolean TRUE value) | ||||||
Logics & highlights
Single-phase to ground fault in ungrounded system
Single-phase to ground fault in Petersen coil grounded system with 100% compensation
Transient ground fault
Transient ground fault power threshold
Transient ground fault detection logic
Definition of Setting Parameters
TRANSIENT GND FLT 1 FUNCTION — This setting enables and disables the Transient Ground Fault Detection function.
TRANSIENT GND FLT 1 SOURCE — This setting selects the signal source for Transient Ground Fault Detection function.
TRANSIENT GND FLT 1 VOLT — The element uses neutral voltage (that is, three times the zero-sequence voltage). This setting allows selecting between the internally calculated neutral voltage or the externally supplied voltage (broken delta VT connected to the auxiliary channel bank of the relay). When the latter selection is made, the auxiliary channel must be identified by the user as a neutral voltage under the VT bank settings. This element operates when the auxiliary voltage is configured as neutral.
TRANSIENT GND FLT 1 AMP — The element responds to the neutral current (that is, three times zero-sequence current), either calculated internally from the phase currents or supplied externally via the ground CT input from more accurate sources such as the core balanced CT. This setting allows selecting the source of the operating current.
TRANSIENT GND FLT 1 PWR THLD — This setting is used to calculate dynamic power threshold which in turn is used to determine residual fault direction. Increasing the value of this setting increases the security and decreases the sensitivity of the element. The minimum value that can be applied to this setting to avoid overlap with “small P/Q” area is 3 W. As shown in the next figure, “small P/Q” area refers to the condition when the calculated transient reactive or active power is small enough to introduce ambiguity in sensing the direction of the fault. This setting is given in secondary value.
TRANSIENT GND FLT 1 VOLT PKP — Voltage pickup threshold that is used to determine if Transient Ground Fault Detection element starts or not. If the measured neutral voltage is above this setting the element Transient Ground Fault Detection starts. Typical value of this setting is 0.10 pu.
TRNST GND FLT 1 BLK — Assertion of the FlexLogic operand assigned to this setting blocks operation of Transient Ground Fault Detection element.
TRANSIENT GND FLT 1 EVENTS — This setting enables and disables the logging of Transient Ground Fault Detection events in the event recorder.