2Nd Harmonic Block/Inrush Restraint (81Hbl2) Phase Elements Only; Demand; Figure 6.6-1 Functional Diagram For Harmonic Block Feature (81Hbl2) - Siemens Solkor 7PG2113 Technical Manual

6.6 2nd Harmonic Block/Inrush Restraint (81HBL2) phase
elements only
Inrush restraint detector elements are provided, these monitor the line currents.
The inrush restraint detector can be used to block the operation of selected elements during transformer
magnetising inrush conditions.
The 81HBL2 Bias setting allows the user to select between Phase, Sum and Cross methods of measurement:
Each phase is inhibited separately.
Phase
With this method the square root of the sum of the squares of the second harmonic in each
Sum
phase is compared to each operate current individually.
All phases are inhibited when any phase detects an inrush condition.
Cross
An output is given where the measured value of the second harmonic component is above the 81HBL2 setting.

Figure 6.6-1 Functional Diagram for Harmonic Block Feature (81HBL2)

6.7

Demand

Maximum, minimum and mean values of line currents, voltages and power (where applicable) are available as
instruments which can be read in the relay INSTRUMENTS MENU or via Reydisp.
The Gn Demand Log Time Sync when set as ENABLED configures the Demand Log Update Period (see
below) equal to the DATA STORAGE > Data Log Period setting.
The Gn Demand Log Update Period setting is used to define the time/duration after which the instrument is
updated. The updated value indicates the maximum, minimum and mean values for the defined period. Note that
this setting can be over-ridden by the Gn Demand Log Time Sync setting.
The Gn Demand Window setting defines the maximum period of time over which the demand values are valid. A
new set of demand values is established after expiry of the set time.
The Gn Demand Window Type can be set to FIXED or PEAK or ROLLING.
When set to FIXED the maximum, minimum and mean values demand statistics are calculated over
fixed Window duration. At the end of each window the internal statistics
are reset and a new window is started.
When set to PEAK the maximum and minimum values since the feature was reset are recorded.
When set to ROLLING the maximum, minimum and mean values demand statistics are calculated over
a moving Window duration. The internal statistics
are updated when the window advances every Updated Period.
The statistics can be reset from a binary input or communication command, after a reset the update period and
window are immediately restarted.
©2010 Siemens Protection Devices Limited
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7PG2113/4/5/6 Solkor Description of Operation
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81HBL2
L1 81HBL2
L2 81HBL2
L3 81HBL2
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