Overview
The “Neutral directional overcurrent” element provides both forward and reverse fault direction indications for the NEUTRAL DIR OC1 FWD and NEUTRAL DIR OC1 REV operands, respectively.
For more detailed information on “Neutral directional overcurrent” element, refer to GE, 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 |
| B30, C70, D30, D60, F60, G30, G60, L30, L60, L90, M60, N60, T60 | CCD7 | Neutral Directional Overcurrent 1 Function | 0 to 1 | — | 1 | F102 | 0 (Disabled) |
| " | CCD8 | Neutral Directional Overcurrent 1 Source | 0 to 5 | — | 1 | F167 | 0 (SRC 1) |
| " | CCD9 | Neutral Directional Overcurrent 1 Polarizing | 0 to 4 | — | 1 | F230 | 0 (Voltage) |
| " | CCDA | Neutral Directional Overcurrent 1 Forward ECA | -90 to 90 | ° Lag | 1 | F002 | 75 |
| " | CCDB | Neutral Directional Overcurrent 1 Forward Limit Angle | 40 to 90 | degrees | 1 | F001 | 90 |
| " | CCDC | Neutral Directional Overcurrent 1 Forward Pickup | 0.006 to 30 | pu | 0.001 | F001 | 50 |
| " | CCDD | Neutral Directional Overcurrent 1 Reverse Limit Angle | 40 to 90 | degrees | 1 | F001 | 90 |
| " | CCDE | Neutral Directional Overcurrent 1 Reverse Pickup | 0.006 to 30 | pu | 0.001 | F001 | 50 |
| " | CCDF | Neutral Directional Overcurrent 1 Target | 0 to 2 | — | 1 | F109 | 0 (Self-reset) |
| " | CCE0 | Neutral Directional Overcurrent 1 Block | 0 to 4294967295 | — | 1 | F300 | 0 |
| " | CCE2 | Neutral Directional Overcurrent 1 Events | 0 to 1 | — | 1 | F102 | 0 (Disabled) |
| " | CCE3 | Neutral Directional Overcurrent 1 Polarizing Voltage | 0 to 1 | — | 1 | F231 | 0 (Calculated V0) |
| " | CCE4 | Neutral Directional Overcurrent 1 Op Current | 0 to 1 | — | 1 | F196 | 0 (Calculated 3I0) |
| " | CCE5 | Neutral Directional Overcurrent 1 Offset | 0 to 250 | ohms | 0.01 | F001 | 0 |
| " | CCE6 | Neutral Directional Overcurrent 1 Pos Seq Restraint | 0 to 0.5 | — | 0.001 | F001 | 63 |
| " | CCE7 | Neutral Directional Overcurrent 1 CT Source | 0 to 30 | — | 1 | F677 | 0 (None) |
| D30, D60, F60, G30, G60, L30, L60, L90, M60, N60, T60 | CCE8 | …Repeated for Neutral Directional Overcurrent 2 | |||||
| B30, N60, T60 | CCF9 | …Repeated for Neutral Directional Overcurrent 3 | |||||
| B30 | CD0A | …Repeated for Neutral Directional Overcurrent 4 | |||||
| " | CD1B | …Repeated for Neutral Directional Overcurrent 5 | |||||
| " | CD2C | …Repeated for Neutral Directional Overcurrent 6 |
| 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 | ||||||
| F196 | 0 = Calculated 3I0, 1 = Measured IG | ||||||
| F230 | 0= Voltage, 1 = Current, 2 = Dual, 3 = Dual-V, 4 = Dual-I | ||||||
| F231 | 0 = Calculated V0, 1 = Measured VX | ||||||
| F300 | 0 : Off (This is boolean FALSE value), 1 : On (This is boolean TRUE value) | ||||||
| F677 | 0 = None, 1 = SRC 1, 2 = SRC 2, 3 = SRC 3, 4 = SRC 4, 5 = SRC 5, 6 = SRC 6, 7 = SRC 7 | ||||||
Logics & highlights
Quantities definition
Neutral directional voltage-polarized characteristics
Neutral directional overcurrent logic
Definition of Setting Parameters
NEUTRAL DIR OC1 POLARIZING — This setting selects the polarizing mode for the directional unit.
NEUTRAL DIR OC1 POL VOLT — Selects the polarizing voltage used by the directional unit when “Voltage,” “Dual,” “Dual-V,” or “Dual-I” polarizing mode is set. The polarizing voltage can be programmed to be either the zero-sequence voltage calculated from the phase voltages (“Calculated V0”) or supplied externally as an auxiliary voltage (“Measured VX”).
NEUTRAL DIR OC1 OP CURR — This setting indicates whether the 3I_0 current calculated from the phase currents, or the ground current is used by this protection. This setting acts as a switch between the neutral and ground modes of operation (ANSI devices 67N and 67G). If set to “Calculated 3I0,” the element uses the phase currents and applies the positive sequence restraint. If set to “Measured IG,” the element uses ground current supplied to the ground CT of the CT bank configured as NEUTRAL DIR OC1 SOURCE. If this setting is “Measured IG,” then the NEUTRAL DIR OC1 POLARIZING setting must be “Voltage”, as it is not possible to use the ground current as an operating and polarizing signal simultaneously. IG current has to be above 0.05 ps to be used as operate quantity.
NEUTRAL DIR OC1 POS-SEQ RESTRAINT — This setting controls the amount of the positive-sequence restraint. Set it to 0.063 for backward compatibility with firmware revision 3.40 and older. Set it to zero to remove the restraint. Set it higher if large system unbalances or poor CT performance are expected.
NEUTRAL DIR OC1 OFFSET — This setting specifies the offset impedance used by this protection. The primary application for the offset impedance is to guarantee correct identification of fault direction on series compensated lines. In regular applications, the offset impedance ensures proper operation even if the zero-sequence voltage at the relaying point is very small. If this is the intent, the offset impedance is not to be larger than the zero-sequence impedance of the protected circuit. Practically, it shall be several times smaller. Enter the offset impedance in secondary ohms. See the Application of Settings chapter for information on how to calculate this setting.
NEUTRAL DIR OC1 FWD ECA — This setting defines the characteristic angle (ECA) for the forward direction in the “Voltage” polarizing mode. The “Current” polarizing mode uses a fixed ECA of 0°. The ECA in the reverse direction is the angle set for the forward direction shifted by 180°.
NEUTRAL DIR OC1 FWD LIMIT ANGLE — This setting defines a symmetrical (in both directions from the ECA) limit angle for the forward direction.
NEUTRAL DIR OC1 FWD PICKUP — This setting defines the pickup level for the overcurrent unit of the element in the forward direction. When selecting this setting, keep in mind that the design uses a positive-sequence restraint technique for the “Calculated 3I0” mode of operation.
NEUTRAL DIR OC1 REV LIMIT ANGLE — This setting defines a symmetrical (in both directions from the ECA) limit angle for the reverse direction.
NEUTRAL DIR OC1 REV PICKUP — This setting defines the pickup level for the overcurrent unit of the element in the reverse direction. When selecting this setting, keep in mind that the design uses a positive-sequence restraint technique for the “Calculated 3I0” mode of operation.