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1MAC050144-MB C
Section 4
Protection functions
615 series ANSI
263
Technical Manual
Figure 125:
Functional module diagram
Over/under frequency detection
The frequency detection module includes an overfrequency or underfrequency detection
based on the
Operation mode
setting.
In the “Freq>” mode, the measured frequency is compared to the set
Pickup value Freq>
.
If the measured value exceeds the set value of the
Pickup value Freq>
setting, the module
reports the exceeding of the value to the operate logic module.
In the “Freq<” mode, the measured frequency is compared to the set
Pickup value Freq<
.
If the measured value is lower than the set value of the
Pickup value Freq<
setting, the
module reports the value to the operate logic module.
dF/dt detection
The frequency gradient detection module includes a detection for a positive or negative
rate-of-change (gradient) of frequency based on the set
Pickup value df/dt
value. The
negative rate-of-change protection is selected when the set value is negative. The positive
rate-of-change protection is selected when the set value is positive. When the frequency
gradient protection is selected and the gradient exceeds the set
Pickup value df/dt
value,
the module reports the exceeding of the value to the operate logic module.
Blocking logic
This module is used for combining different protection criteria based on the frequency and
the frequency gradient measurement to achieve a more sophisticated behavior of the
function. The criteria are selected with the
Operation mode
setting.
The IED does not accept the set value “0.00” for the Pickup value df/dt
setting.
F
Over/under
frequency
detection
TRIP
PICKUP
dF/dt
dF/dt
detection
BLOCK
Blocking
logic
Trip logic
TRIP_OFRQ
TRIP_UFRQ
PICKUP_OFRQ
PICKUP_UFRQ
TRIP_FRG
PICKUP_FRG
Summary of Contents for 615 Series ANSI
Page 1: ...Relion Protection and Control 615 series ANSI Technical Manual ...
Page 2: ......
Page 29: ...1MAC050144 MB C Section 615 series ANSI 22 Technical Manual ...
Page 389: ...Section 4 1MAC050144 MB C Protection functions 382 615 series ANSI Technical Manual ...
Page 485: ...Section 6 1MAC050144 MB C Supervision functions 478 615 series ANSI Technical Manual ...
Page 635: ...Section 10 1MAC050144 MB C Other functions 628 615 series ANSI Technical Manual ...
Page 711: ...Section 16 1MAC050144 MB C Glossary 704 615 series ANSI Technical Manual ...
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