Setting Guidelines - Hitachi Relion 670 Series Applications Manual

1MRK511407-UUS Rev. N
Due to the technical difficulties mentioned above, protection should be provided, which disconnects the
distributed generation once it is electrically isolated from the main grid supply. Various techniques are
used for detecting Loss of Mains. However, the present feature of voltage supervision focuses on voltage
vector shift.
For islanding based on vector shift protection, the logic shown in Figure
breaker. With this logic, reliable tripping can be ensured as angle shift has been detected in all the three
phase voltages.
V3P*
BLOCK
ANSI18000903 V1 EN-US
Figure 79:
The vector shift detection guarantees fast and reliable detection of mains failure in almost all operational
conditions when a distributed generation unit is running in parallel with the mains supply, but in certain
cases this may fail.
If the active and reactive power generated by the distributed generation units is nearly balanced (for
example, if the power mismatch or unbalance is less than 5...10%) with the active and reactive power
consumed by loads, a large enough voltage phase shift may not occur which can be detected by the
vector shift algorithm. This means that the vector shift algorithm has a small non-detection zone (NDZ)
which is also dependent on the type of generators, loads, network and start or operate value of the vector
shift algorithm.
Other network events like capacitor switching, switching of very large loads in weak network or
connection of parallel transformer at HV/MV substation, in which the voltage magnitude is not changed
considerably (unlike in faults) can potentially cause maloperation of vector shift algorithm, if very
sensitive settings are used.
The vector shift detection also protects synchronous generators from damaging due to islanding or loss-
of-mains.
13.3.3

Setting guidelines

Operation: To enable/disable the delta supervision function.
Umin: The minimum start level setting should be set as % of UBase. This setting enables the function to
start detecting delta. Typical setting is 10% of UBase. If the MeasMode setting is set as phase to ground,
this setting is taken as 50% of the set value.
MeasMode: To detect the mode of measurement; phase to phase or phase to ground.
OpMode: To select the mode of operation. For protection applications, this should be set to
Instantaneous 1 cycle old. Load supervision can be done using vector shift mode or DFT mag mode.
Phasor measurement unit RES670
Application manual
DELVSPVC (78V)
BFI_3P
PICKUP_A
PICKUP_B
PICKUP_C
STRISE
STRISE_A
STRISE_B
STRISEL3
STLOW
STLOW_A
STLOW_B
STLOWL3
DELMAG_A
DELMAG_B
DELMAGL3
DELVSPVC connection diagram
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78V Pickup
AND
ANSI18000903‐1‐en.vsdx
Secondary system supervision
79 should be used to trip the
GUID-9356F1C8-9EBA-43E3-8445-CB74E12BC57E v3
Section 13
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