The GRZ100 is provided with the following recording functions:
Fault recording
Event recording
Disturbance recording
These records are displayed on the LCD of the relay front panel or on the local or remote PC. For samples of LCD screen, see Section 4.2.
3.4.1 Fault Recording
Fault recording is started by a tripping command of the GRZ100, a tripping command of the external main protection or PLC command by user-setting (max. 4) and the following items are recorded for one fault:
Date and time of fault occurrence
Faulted phase
Tripping phase
Tripping mode
Fault location
Relevant events
Power system quantities
Up to 8 most-recent faults are stored as fault records. If a new fault occurs when 8 faults have been stored, the record of the oldest fault is deleted and the record of the latest fault is then stored.
Date and time of fault occurrence
The time resolution is 1 ms using the relay internal clock.
To be precise, this is the time at which a tripping command has been output, and thus it is approximately 10 ms after the occurrence of the fault.
Fault phase
The faulted phase is displayed when tripping by a distance measuring element. The fault phase is determined by the "fault phase detection logic". However, the fault phase depends on the setting of the phase selection element UVC.
In case of the tripping by a backup protection, the fault phase is not displayed and the "---" marked is displayed.
Tripping phase
This is the phase to which a tripping command is output. Tripping mode
This shows the protection scheme that the tripping command is output. Fault location
The fault location is displayed against the fault within the protected line tripped by a distance measuring element. The distance to the fault point calculated by the fault locator is recorded.
The distance is expressed in km and as a percentage (%) of the line length. For the fault locator, see Section 2.7.4.
Relevant events
Such events as autoreclose, re-tripping following the reclose-on-to-a fault or autoreclose and tripping for evolving faults are recorded with time-tags.
Power system quantities
The following power system quantities in pre-faults and post-faults are recorded. The pre-fault power system quantities are values at 10 seconds before tripping.
(However, the power system quantities are not recorded for evolving faults.) - Magnitude and phase angle of phase voltage (Va, Vb, Vc)
- Magnitude and phase angle of phase-to-phase voltage (Vab, Vbc, Vca) - Magnitude and phase angle of symmetrical component voltage (V1, V2, V0) - Magnitude and phase angle of phase voltage for autoreclose (Vs1, Vs2) - Magnitude and phase angle of phase current (Ia, Ib, Ic)
- Magnitude and phase angle of phase-to-phase current (Iab, Ibc, Ica) - Magnitude and phase angle of symmetrical component current (I1, I2, I0) - Magnitude of parallel line zero sequence current (I0m)
- Resistive and reactive component of phase impedance (Ra, Rb, Rc, Xa, Xb, Xc)
- Resistive and reactive component of phase-to-phase impedance (Rab, Rbc, Rca, Xab, Xbc, Xca)
- Percentage of thermal capacity (THM%)
Phase angles above are expressed taking that of positive sequence voltage as a reference phase angle. Phase impedance and phase-to-phase impedance are the ones seen by the reactance elements.
3.4.2 Event Recording
The events shown are recorded with a 1 ms resolution time-tag when the status changes. The user can set a maximum of 128 recording items, and their status change mode. The event items can be assigned to a signal number in the signal list. The status change mode is set to “On” (only recording On transitions) or “On/Off”(recording both On and Off transitions) mode by setting. The “On/Off” mode events are specified by “Bi-trigger events” setting. If the “Bi-trigger events” is set to “100”, No.1 to 100 events are “On/Off” mode and No.101 to 128 events are “On” mode. The name of an event cannot be set on LCD. It can set only by RSM100. Maximum 22 characters can be set and can be viewed on both of the LCD and RSM Setting(view) screen. But the LCD screen of event record displays only 11 characters. Therefore, it is recommended the maximum 11 characters are set.
The elements necessary for event recording and their setting ranges are shown in the table below. The default setting of event record is shown in Appendix H.
Element Range Step Default Remarks
BITRN 0 - 128 1 100 Number of bi-trigger(on/off) events EV1 – EV128 0 - 3071 Assign the signal number
Up to 480 records can be stored. If an additional event occurs when 480 records have been stored, the oldest event record is deleted and the latest event record is then stored.
3.4.3 Disturbance Recording
Disturbance recording is started when overcurrent or undervoltage starter elements operate or a tripping command is output, or PLC command by user-setting (max. 4) is outputted. The records include 8 analog signals (Va, Vb, Vc, Ia, Ib, Ic, 3I0, 3I0m), 32 binary signals and the dates and times at which recording started. Any binary signal in shown in Appendix B can be assigned by the binary signal setting of disturbance record. The default setting of binary signal is shown in Appendix H.
The name of binary signal can be set only by RSM100. Maximum 22 characters can be set and can be viewed on both of the LCD and RSM Setting(view) screen. But the waveform data analysis screen of disturbance record displays up to 11 characters of them. Therefore, it is recommended the maximum 11 characters are set.
The LCD display only shows the dates and times of the disturbance records stored. Details can be displayed on a PC. For how to obtain disturbance records on the PC, see the PC software instruction manual.
The pre-fault recording time is fixed at 0.3s and the post-fault recording time can be set between 0.1 and 3.0s and the default setting is 1.0s.
The number of records stored depends on the post-fault recording time and the relay model. The typical number of records stored in 50Hz and 60Hz power system is shown in Table 3.4.3.1.
Note: If the recording time setting is changed, the records stored so far are deleted.
Table 3.4.3.1 Post Fault Recording Time and Number of Disturbance Records Stored
Recording time 0.1s 0.5s 1.0s 1.5s 2.0s 2.5s 3.0s
50Hz 40 20 15 10 8 7 6
Settings
The elements necessary for initiating a disturbance recording and their setting ranges are shown in the table below.
Element Range Step Default Remarks
Timer 0.1-3.0 s 0.1 s 1.0 s Post-fault recording time
OCP-S 0.5-250.0 A 0.1 A 10.0 A Overcurrent detection (phase fault) (0.1-50.0 A 0.1 A 2.0 A) (*)
OCP-G 0.5-250.0 A 0.1 A 5.0 A Overcurrent detection (earth fault) (0.1-50.0 A 0.1 A 1.0 A)
UVP-S 0-132 V 1 V 88 V Undervoltage detection (phase fault) UVP-G 0-76 V 1 V 51 V Undervoltage detection (earth fault)
(*) Current values shown in the parentheses are for the case of a 1A rating. Other current values are for the case of a 5A rating.
Starting the disturbance recording by a tripping command or the starter elements listed above is enabled or disabled by setting the following scheme switches with identical names with the starter elements except the switch [TRIP].
Element Range Step Default Remarks
TRIP OFF/ON ON Start by tripping command OCP-S OFF/ON ON Start by OCP-S operation OCP-G OFF/ON ON Start by OCP-G operation UVP-S OFF/ON ON Start by UVP-S operation UVP-G OFF/ON ON Start by UVP-G operation