7SR11 & 7SR12 Description Of Operation
©2017 Siemens Protection Devices Limited Chapter 1 Page 55 of 88
3.13 Voltage Protection: Negative Phase Sequence
Overvoltage (47) – 7SR12
Negative phase sequence (NPS) voltage (V2) is a measure of the quantity of unbalanced voltage in the system.
The relay derives the NPS voltage from the three input voltages (VL1, VL2 and VL3).
Two elements are provided
47-1 & 47-2.
Voltage elements can be blocked if all phase voltages fall below the
47 U/V Guard
setting.
47-n Setting
sets the pick-up voltage level for the element.
The
47-n Hysteresis
setting allows the user to vary the pick-up/drop-off ratio for the element.
An output is given after elapse of the
47-n Delay
setting.
Operation of the negative phase sequence voltage elements can be inhibited from:
Inhibit 47-n
A binary or virtual input.
47-n U/V Guarded
Under voltage guard element.
Inhibit 47-n
47-n Element
Enabled
Disabled
47-n
47-n Delay
&
c
47-n Hysteresis
>
47-n Setting
VL1
VL2
VL3
NPS
Filter
V2
General Pickup
Figure 3-28 Logic Diagram: NPS Overvoltage Protection (47)
3.14 Voltage Protection: Neutral Overvoltage (59N) – 7SR12
Two Neutral Overvoltage (or Neutral Voltage Displacement) elements are provided
59NIT & 59NDT
.
The relay utilises fundamental voltage measurement values for this function. The element can use a direct
measurement 3Vo connection from the voltage transformer or calculate values from a phase to neutral
connections from the voltage transformer.
The 59NIT element can be configured to be either definite time lag (DTL) or inverse definite minimum time
(IDMT),
59NIT Setting
sets the pick-up voltage level (3V0) for the element.
An inverse definite minimum time (IDMT) can be selected using
59NIT Char
. A time multiplier is applied to the
characteristic curves using the
59NIT Time Mult
setting (M):
Alternatively, a definite time lag delay (DTL) can be chosen using
59NITChar
. When Delay (DTL) is selected the
time multiplier is not applied and the
59NIT Delay (DTL)
setting is used instead.
An instantaneous or definite time delayed reset can be applied using the
59NIT Reset
setting.
The 59NDT element has a DTL characteristic.
59NDT Setting
sets the pick-up voltage (3V0) and
59NDT Delay
the follower time delay.
Operation of the neutral overvoltage elements can be inhibited from:
Inhibit 59NIT
A binary or virtual input.
Inhibit59NDT
A binary or virtual input.
[ ]
ms
1
M
*
1000
t
Vs
3Vo
op
−
=
Summary of Contents for Argus 7SR11
Page 1: ...Energy Management 7SR11 7SR12 Argus Overcurrent Relay Reyrolle Protection Devices ...
Page 2: ......
Page 4: ...7SR11 7SR12 Argus Contents 2015 Siemens Protection Devices Limited Page 2 of 2 ...
Page 170: ...7SR120 Technical Manual Chapter 4 Page 2 of 84 2017 Siemens Protection Devices Limited ...
Page 174: ...7SR120 Technical Manual Chapter 4 Page 6 of 84 2017 Siemens Protection Devices Limited ...
Page 196: ...7SR120 Technical Manual Chapter 4 Page 28 of 84 2017 Siemens Protection Devices Limited ...
Page 242: ...7SR120 Technical Manual Chapter 4 Page 74 of 84 2017 Siemens Protection Devices Limited ...
Page 244: ...7SR120 Technical Manual Chapter 4 Page 76 of 84 2017 Siemens Protection Devices Limited ...
Page 246: ...7SR120 Technical Manual Chapter 4 Page 78 of 84 2017 Siemens Protection Devices Limited ...
Page 254: ...7SR11 7SR12 Installation Guide Chapter 5 Page 2 of 32 2017 Siemens Protection Devices Limited ...
Page 358: ...7SR11 7SR12 Applications Guide Page 2 of 48 2017 Siemens Protection Devices Limited ...
Page 405: ......