
4–87
System Setup and Setpoints – 4
59N Overvoltage, Neutral Circuit or Zero
Sequence
The Neutral Overvoltage function (59N) provides
stator ground fault protection for high impedance
grounded generators. The 59N function can provide
ground fault protection for 90–95% of the stator
winding (measured from the terminal end).
The 59N function provides three setpoints, and
responds only to the fundamental frequency
component, rejecting all other harmonic components.
Ranges and increments are presented in Figure
4-65.
59N #1 PICKUP
Volts
59N #1 DELAY
Cycles
59N 20HZ INJECTION MODE
disable ENABLE
59N #2 and 59N #3 screens are identical to
59N #1.
With typical grounding transformer ratios and a typical
minimum setting of 5 volts, this protection is capable of
detecting ground faults in about 95% of the generator stator
winding from the terminal end.
If grounded-wye/grounded-wye VTs are connected at
the machine terminals, the voltage relay must be time
coordinated with VT fuses for faults on the transformer
secondary winding. If relay time delay for coordination is not
acceptable, the coordination problem can be alleviated by
grounding one of the secondary phase conductors instead
of the secondary neutral. When this technique is used, the
coordination problem still exists for ground faults on the
secondary neutral conductor. Thus, its usefulness is limited
to those applications where the exposure to ground faults
on the secondary neutral is small.
Since system ground faults can induce zero sequence
voltages at the generator due to transformer capacitance
coupling, this relay must coordinate with the system ground
fault relaying. It is possible to set 59N#1, 59N#2, and 59N#3 to
coordinate with the PT secondary fuses, and also coordinate
with worst case capacitive coupling interference voltage from
system ground faults (high side of the GSU).
For applications where the M-3425A relay (where the 64S
function is purchased or not) is used with 100% Stator
Ground protection with 20 Hz injection schemes, the 59N
20 Hz injection mode must be enabled in order to calculate
the voltage magnitude accurately for the 59N function, due
to the 20 Hz injection voltage. The time delay accuracy of
the function is –1 to +5 cycles when the 20 Hz injection
mode is enabled.
Содержание M-3425A
Страница 1: ...Instruction Book M 3425A Generator Protection ...
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Страница 39: ...800 3425A SP 10MC2 07 12 2001 Beckwith Electric Co All Rights Reserved Printed in U S A 01 67 04 25 03 ...
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Страница 73: ...M 3425A Instruction Book 2 10 Path Monitor Primary Metering Status Figure 2 4 Primary Metering Status Screen ...
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Страница 97: ...M 3425A Instruction Book 3 2 Figure 3 2 IPScom Main Screen ...
Страница 103: ...M 3425A Instruction Book 3 8 Path Monitor Primary Metering and Status Figure 3 9 Primary Metering Status Screen ...
Страница 105: ...M 3425A Instruction Book 3 10 Path Monitor Secondary Metering and Status Figure 3 10 Secondary Metering Status Screen ...
Страница 123: ...M 3425A Instruction Book 3 28 Figure 3 30 View Sequence of Events Recorder Screen ...
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Страница 162: ...4 31 System Setup and Setpoints 4 Figure 4 15 IPScom Relay Setup System Dialog Screen ...
Страница 180: ...4 49 System Setup and Setpoints 4 Table 4 5 Impedance Calculation Figure 4 30 Phase Distance 21 Setpoint Ranges ...
Страница 183: ...4 52 M 3425A Instruction Book Figure 4 32 Volts Per Hertz 24 Setpoint Ranges ...
Страница 187: ...4 56 M 3425A Instruction Book Figure 4 34 Sync Check 25 Setpoint Ranges ...
Страница 202: ...4 71 System Setup and Setpoints 4 Figure 4 50 49 Function Overload Curves ...
Страница 203: ...4 72 M 3425A Instruction Book Figure 4 51 Stator Thermal Protection 49 Setpoint Ranges ...
Страница 215: ...4 84 M 3425A Instruction Book Figure 4 62 Phase Overvoltage 59 Setpoint Ranges ...
Страница 219: ...4 88 M 3425A Instruction Book Figure 4 65 Overvoltage Neutral Circuit or Zero Sequence 59N Setpoint Ranges ...
Страница 236: ...4 105 System Setup and Setpoints 4 Figure 4 77 Residual Directional Overcurrent 67N Setpoint Ranges ...
Страница 239: ...4 108 M 3425A Instruction Book Figure 4 80 Out of Step 78 Setpoint Ranges ...
Страница 242: ...4 111 System Setup and Setpoints 4 Figure 4 82 Frequency 81 Setpoint Ranges ...
Страница 261: ...M 3425A Instruction Book 5 6 Figure 5 5 Mounting Dimensions for GE L 2 Cabinet H3 and H4 ...
Страница 277: ...M 3425A Instruction Book 5 22 Figure 5 14 M 3425A Circuit Board ...
Страница 278: ...Installation 5 5 23 Figure 5 15 M 3425A Circuit Board Expanded I O ...
Страница 280: ...Installation 5 5 25 Figure 5 17 20 Hz Frequency Generator Housing Panel Surface Mount ...
Страница 281: ...M 3425A Instruction Book 5 26 Figure 5 18 20 Hz Frequency Generator Housing Panel Flush Mount ...
Страница 282: ...Installation 5 5 27 Figure 5 19 20 Hz Band Pass Filter Housing Panel Surface Mount ...
Страница 283: ...M 3425A Instruction Book 5 28 Figure 5 20 20 Hz Band Pass Filter Housing Panel Flush Mount ...
Страница 284: ...Installation 5 5 29 Figure 5 21 20 Hz Measuring Current Transformer 400 5 A CT ...
Страница 421: ...D 2 M 3425A Instruction Book Figure D 1 Volts Hz 24 Inverse Curve Family 1 Inverse Square ...
Страница 422: ...Inverse Time Curves Appendix D D 3 Figure D 2 Volts Hz 24 Inverse Family Curve 2 ...
Страница 423: ...D 4 M 3425A Instruction Book Figure D 3 Volts Hz 24IT Inverse Curve Family 3 ...
Страница 424: ...Inverse Time Curves Appendix D D 5 Figure D 4 Volts Hz 24IT Inverse Curve Family 4 ...
Страница 427: ...D 8 M 3425A Instruction Book Figure D 5 BECO Definite Time Overcurrent Curve ...
Страница 428: ...Inverse Time Curves Appendix D D 9 Figure D 6 BECO Inverse Time Overcurrent Curve ...
Страница 429: ...D 10 M 3425A Instruction Book Figure D 7 BECO Very Inverse Time Overcurrent Curve ...
Страница 430: ...Inverse Time Curves Appendix D D 11 Figure D 8 BECO Extremely Inverse Time Overcurrent Curve ...
Страница 437: ...D 18 M 3425A Instruction Book Figure D 15 IEEE Extremely Inverse Time Overcurrent Curves ...
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