84-48
9424200996
Settings Calculation Examples
BE1-11
m
Figure 84-60. Protection, Voltage, Overvoltage (59P-1) Screen
Protection - Power
A synchronous motor is started by a prime mover, by a “pony motor,” induction motor methods (shorted
field windings, squirrel cage type winding—amortisseur or damper winding) or other means to achieve
near synchronous speed. Applying the external rotor excitation, the rotor locks its speed with the rotating
stator magnetic field; now the motor shaft is rotating at synchronous speed and the machine produces
usable motor torque. The motor power factor is at unity (1.0). See the synchronous motor V curves in
Figure 84-32.
If too much load is applied to the motor, the power factor begins to drift from unity. Adding more loads
causes the rotor to go out of step with the rotating magnetic field and no shaft torque is developed (if no
additional excitation is added). At this point the synchronous motor stops.
When the motor power factor cannot be maintained at the manufacturer’s specification the motor should
trip; in this case 0.9 PF lagging.
A unique capability of a synchronous motor is that it can provide var support and improve the power
system total power factor; this operation mode is also known as a synchronous condenser. In fact, it can
be operated with variable excitation to produce a leading power factor (overexcited is a variable capacitor
and underexcited is a variable inductor), further stabilizing the power system power factor. In practice, the
field excitation is varied to maintain a constant terminal voltage across a load, so the synchronous motor
behaves as a type of voltage regulator.
The Power Factor (55) element operates during synchronous motor operation. To ensure that the
element is operates only when the motor is in synchronous mode, the logic timer shown in Figure 84-69 is
added to the element Block input. Figure 84-61 shows a delay of 1 second. Zero (0) or more delay can be
set for your particular situation.
As shown in the synchronous motor V curves (Figure 84-32) the motor power factor at 1 p.u. load can
begin to threaten maintained operation of the motor. This condition occurs at 0.85 pf leading.
Configure the Power Factor (55) element as shown in Figure 84-62. A slight delay allows automatic
excitation equipment or a remedial action scheme an opportunity to correct an out-of-range operation
condition.
Set the Lagging Pickup to 0.90, Leading Pickup to 0.85, and Time Delay to 5 seconds (5000 ms).
Summary of Contents for BE1-11m
Page 8: ...vi 9424200996 Revision History BE1 11m...
Page 12: ...x 9424200996 Contents BE1 11m...
Page 21: ...9424200996 1 9 BE1 11m Introduction Figure 1 1 Style Chart...
Page 22: ...1 10 9424200996 Introduction BE1 11m...
Page 40: ...3 6 9424200996 Controls and Indicators BE1 11m Figure 3 3 Front Panel Display Setup Screen...
Page 54: ...5 6 9424200996 Phase Undervoltage 27P Protection BE1 11m...
Page 56: ...6 2 9424200996 Negative Sequence Voltage 47 Protection BE1 11m...
Page 61: ...9424200996 7 5 BE1 11m Phase Overvoltage 59P Protection Figure 7 3 Overvoltage Settings Screen...
Page 62: ...7 6 9424200996 Phase Overvoltage 59P Protection BE1 11m...
Page 68: ...8 6 9424200996 Auxiliary Overvoltage 59X Protection BE1 11m...
Page 80: ...12 4 9424200996 Instantaneous Overcurrent 50 Protection BE1 11m...
Page 84: ...13 4 9424200996 Breaker Failure 50BF Protection BE1 11m...
Page 92: ...14 8 9424200996 Inverse Overcurrent 51 Protection BE1 11m...
Page 105: ...9424200996 18 3 BE1 11m Power Factor 55 Protection Figure 18 2 Power Factor Settings Screen...
Page 106: ...18 4 9424200996 Power Factor 55 Protection BE1 11m...
Page 110: ...19 4 9424200996 Resistance Temperature Detector 49RTD Protection BE1 11m...
Page 118: ...20 8 9424200996 Thermal Curve 49TC Protection BE1 11m...
Page 122: ...22 2 9424200996 Starts per Time Interval 66 Protection BE1 11m...
Page 124: ...23 2 9424200996 Restart Inhibit Protection BE1 11m...
Page 140: ...28 4 9424200996 Breaker Control Switch 101 BE1 11m...
Page 148: ...29 8 9424200996 Setting Groups BE1 11m...
Page 156: ...30 8 9424200996 Metering BE1 11m Figure 30 11 RTD Meter Screen...
Page 158: ...31 2 9424200996 Digital Points BE1 11m Figure 31 2 Digital Points Monitor Screen...
Page 177: ...9424200996 34 5 BE1 11m Motor Reporting Figure 34 9 Learned Motor Data Screen...
Page 178: ...34 6 9424200996 Motor Reporting BE1 11m...
Page 184: ...35 6 9424200996 Alarms BE1 11m...
Page 186: ...36 2 9424200996 Differential Reporting BE1 11m...
Page 196: ...38 4 9424200996 Demands BE1 11m...
Page 198: ...39 2 9424200996 Load Profile BE1 11m...
Page 208: ...41 6 9424200996 Trip Circuit Monitor 52TCM BE1 11m...
Page 212: ...42 4 9424200996 Fuse Loss 60FL BE1 11m...
Page 218: ...43 6 9424200996 BESTnet Plus BE1 11m Figure 43 8 Power Quality Page...
Page 221: ...9424200996 44 3 BE1 11m Mounting Figure 44 3 Case Side Dimensions...
Page 235: ...9424200996 45 5 BE1 11m Terminals and Connectors Figure 45 7 Example of Reversed CT Polarity...
Page 236: ...45 6 9424200996 Terminals and Connectors BE1 11m...
Page 269: ...9424200996 48 15 BE1 11m BESTlogic Plus Figure 48 4 Logic Page 1 for Default Logic...
Page 288: ...49 10 9424200996 Communication BE1 11m Figure 49 14 Modbus Mapping Screen...
Page 306: ...52 4 9424200996 Device Information BE1 11m...
Page 314: ...53 8 9424200996 Configuration BE1 11m Figure 53 3 Display Units Screen...
Page 318: ...54 4 9424200996 Introduction to Testing BE1 11m...
Page 330: ...56 6 9424200996 Commissioning Testing BE1 11m...
Page 336: ...58 4 9424200996 Phase Undervoltage 27P Test BE1 11m...
Page 340: ...59 4 9424200996 Phase Overvoltage 59P Test BE1 11m...
Page 352: ...60 12 9424200996 Auxiliary Overvoltage 59X Test BE1 11m...
Page 360: ...61 8 9424200996 Frequency 81 Test BE1 11m...
Page 364: ...62 4 9424200996 Instantaneous Undercurrent 37 Test BE1 11m...
Page 376: ...63 12 9424200996 Instantaneous Overcurrent 50 Test BE1 11m...
Page 396: ...65 16 9424200996 Inverse Overcurrent 51 Test BE1 11m...
Page 408: ...67 6 9424200996 Power 32 Test BE1 11m...
Page 412: ...68 4 9424200996 Loss of Excitation Reverse Var Based 40Q Test BE1 11m...
Page 426: ...70 10 9424200996 Thermal Curve 49TC Test BE1 11m...
Page 432: ...72 4 9424200996 Starts per Time Interval 66 Test BE1 11m...
Page 436: ...73 4 9424200996 Restart Inhibit Test BE1 11m...
Page 440: ...74 4 9424200996 Virtual Control Switches 43 Test BE1 11m...
Page 450: ...75 10 9424200996 Logic Timers 62 Test BE1 11m...
Page 464: ...79 8 9424200996 Troubleshooting BE1 11m...
Page 480: ...80 16 9424200996 Specifications BE1 11m...
Page 600: ...84 56 9424200996 Settings Calculation Examples BE1 11m Figure 84 70 Logic Page 4 Part 1...
Page 602: ...84 58 9424200996 Settings Calculation Examples BE1 11m...
Page 608: ...85 6 9424200996 BESTCOMSPlus Settings Loader Tool BE1 11m...
Page 609: ......