ABB Relion 670 Series Applications Manual page 265

1MRK 505 370-UUS Rev. K
DeltaT: This setting defines the number of old cycles data to be used for delta calculation in RMS/DFT
Mag and angle mode. Typical value is 2 cycles. This value is not used if OpMode is chosen as
instantaneous 1 cycle or instantaneous 2 cycle.
tHold: This setting defines the pulse length for supervision start signal. Typical value is 100 ms.
11.4 Current based delta supervision DELISPVC(7I)
11.4.1 Identification
Function description
Current based delta supervision
11.4.2 Application
In power system networks, fault detection and operation of other protection functions is reliably done by
delta supervision functionality. Single phase networks are an important application of delta supervision. In
this type of network, a delta based release criteria is used to release the protection funciton. The
measurement of delta differs from country to country between magnitude, vector or sample based
detection.
In this function, a current based delta supervision is implemented in a phase segregated design. The
delta function has the following features:
• Instantaneous sample based delta detection (vectorial delta)
• True RMS value based delta detection
• DFT magnitude based delta detection
• nd
2
•
rd
3 harmonic based adaption of starting value
Instantaneous sample based delta supervision is very fast; the delta is detected in less than a cycle
typically. This mode can be used for high impedance earth fault detection. All the other supervision
modes like RMS/DFT Mag requires minimum one cycle for delta detection.
Therefore, the choice of delta detection mode should be based on the application requirement.
Instantaneous sample based delta supervision can be used for functions that are used as protection
enabler or fault detector. For time delayed functions, other modes can be used. Current based function
can be used for load supervision also in DFT Mag based delta mode.
11.4.3 Setting guidelines
Operation: This setting is used to enable/disable the delta supervision function.
Imin: The minimum pickup level setting should be set as % of IBase. This setting enables the function to
start detecting delta. Typical setting is 10% of IBase.
MeasMode: This setting is used to detect the mode of measurement; phase to phase or phase to ground.
OpMode: This setting is used to select the mode of operation. For protection applications, this should be
set to Instantaneous 1 cycle old. Load supervision can be done using DFT mag mode.
Busbar protection REB670
Application manual
harmonic blocking of delta function
© 2017 - 2021 Hitachi Power Grids. All rights reserved
IEC 61850 IEC 60617
identification identification
DELISPVC –
Secondary system supervision
GUID-4F012876-FA0A-4A97-9E23-387974304CED v2
GUID-0B735A27-6A7D-40E1-B981-91B689608495 v1
ANSI/IEEE C37.2
device number
7I < >
GUID-5CEAE117-C7BA-46B6-BF24-477285050894 v2
GUID-69D28046-FAC4-4EF3-9886-F7B0F6341196 v2
Section 11
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