Current Based Delta Supervision Delispvc(7I); Identification; Application; Setting Guidelines - Hitachi Relion 670 Series Applications Manual

Section 13
Secondary system supervision
DelU>: To detect the start value for instantaneous sample, RMS, DFT mag based delta detection. Set a
typical value of 50% of UBase to use this function as fault detection.
DelUang>: This setting is used for angle based delta detection. This setting could be used to detect
islanding condition. A typical setting of 8-10 deg. is good to detect a major islanding condition.
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.
13.4

Current based delta supervision DELISPVC(7I)

13.4.1

Identification

Function description
Current based delta supervision
13.4.2

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.
13.4.3

Setting guidelines

Operation: To enable/disable the delta supervision function.
194
harmonic blocking of delta function
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IEC 61850 IEC 60617
identification identification
DELISPVC –
1MRK511407-UUS Rev. N
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 v3
Phasor measurement unit RES670
Application manual