Basler BE1-1051 Application Manual Download Page 28

Page: 28 / 28

Revision C.0 June 2001

Basler Electric Headquarters
Route 143, Box 269,
Highland Illinois USA 62249
Phone +1 618.654.2341
Fax +1 618.654.2351

Basler Electric International
P.A.E. Les Pins, 67319 Wasselonne Cedex
FRANCE
Phone +33 3.88.87.1010
Fax +33 3.88.87.0808

If you have any questions or need

additional information, please contact

Basler Electric Company

Our web site is located at:

http://www.basler.com

e-mail: [email protected]

Summary of Contents for BE1-1051

Page 1: ...GeneratorProtection ApplicationGuide...

Page 2: ...ign of protective relaying systems He worked for Consolidated Edison Company for ten years as a System Engineer He has served as a private consultant since 1982 Updates and additions performed by vari...

Page 3: ...it is rather expected that a 500kW 480V standby reciprocating engine will have less protection than a 400MW base load steam turbine unit One possible common dividing point is that the extra CTs neede...

Page 4: ...ral VFG in Fig 1 Assuming an impedancegroundedgeneratorwhere Z0 SOURCE and ZN ZWINDING the current level is directly proportional to the distance of the point from the generator neutral Fig 1 a so a f...

Page 5: ...rcuit or setting the relay fairly insensitively FIGURE 2 GROUND FAULT RELAYING GENERATOR LOW IMPEDANCE GROUNDING The neutral CT should be selected to produce a secondary current of at least 5A for a s...

Page 6: ...gh rejection of fundamental frequency voltage FIGURE 6 GROUND FAULT NEAR GENERATOR NEUTRAL REDUCES THIRD HARMONIC VOLTAGE IN GENERATOR NEUTRAL DROPPING OUT 27 3N The 27 3N performs a valuable monitori...

Page 7: ...ult as seen by the generator neutral shift sensing relay 59N leading to a generator trip Alternatively assume that the VT corner e g phase A has been grounded If phase B or C fault to ground the fault...

Page 8: ...2 100 5 from the neutral When feeder cables are connected to the gen erator bus the additional capacitance dictates a much lower level of grounding resistance than achieved with a unit connected case...

Page 9: ...hout pre loading For example assuming a pre fault 1pu rated load at 30 degree lag at one second the 3 phase fault value would be 2 4 times rated rather than 1 75 timesrated 1 30 1 75 90 2 4 69 Under t...

Page 10: ...edapproach inhibits operation until the voltage drops below a preset voltage It should be set to function below about 80 of rated voltage with a current pickup of about 50 of generator rated Since the...

Page 11: ...imes tap CDS220 or 0 4A 87G is representa tive of a recommended setting for a moderate mismatch in CT quality and burden Fig 13 also shows 51V relays to back up the 87G and external relays and breaker...

Page 12: ...nchroniz ing when the generator is initially slower than the system Since motoring can occur during a large reactive power flow the real power component needs to be measured at low power factors The B...

Page 13: ...y a mho circle centered about the X axis offset from the R axis by X d 2 Two zones sometimes are used a high speed zone and a time delayed zone FIG 19 LOSS OF EXCITATION USING IMPEDANCE RELAY With com...

Page 14: ...r during a fault To prevent a 60FL from being declared during loss of station power it may be necessary to allow a 3 phase 60F to be declared only when some low level of load current exists FIGURE 22...

Page 15: ...ach set point may be set to recognize either over frequency or underfrequency Multiple frequency set points are available in the BE1 81O U BE1 GPS100 BE1 951 and BE1 1051 Another common need for frequ...

Page 16: ...ld be employed where protection independent of the plant is desired In this case the 67 relays would be placed in the switchyard rather than in the control room While directional overcurrent relay 67...

Page 17: ...reaker depending on the type of fault that is detected For instance if the generator is protected by a 51V and an 87G and only the 51V trips it may be assumed that the fault is external to the generat...

Page 18: ...EXAMPLE OF BARE MINIMUM PROTECTION LOW IMPEDANCE GROUNDING Fig 30 shows the suggested minimum protection with low resistance grounding It includes differential protection which provides fast selectiv...

Page 19: ...ssive generator reactive absorption Ther mal relay 49 protects against stator overheating due to protracted heavy reactive power demands and loss of generator cooling Even if the excitation system is...

Page 20: ...voltage balancerelay 60 field ground relay 64F frequency relay 81 and the 27 50 62 relay combination for inadvertent energization protection Relay 51GN provides a second means of detecting stator gro...

Page 21: ...ures 34 through 37 show the BE1 GPS100 and BE1 CDS220 applied to generator protection Due to logic complexity full details are not shown Details of these applica tions may be found in the respective i...

Page 22: ...20 FIGURE 35 BE1 GPS100 APPLIED TO HIGH IMPEDANCE GROUNDED GENERATOR HI_Z_GND PREPROGRAMMED LOGIC SEE INSTRUCTION MANUAL FOR LOGIC DETAILS...

Page 23: ...FIGURE 36 BE1 CDS220 APPLIED TO GENERATOR FOR 87 PHASE 87 NEUTRAL AND 51 PHASE NEUTRAL GROUND AND NEGATIVE SEQUENCE 21...

Page 24: ...s typical settings for use as a starting point in the setting determi nation procedure The proper settings are heavily influenced by the specifics of each application Typical settings are also used as...

Page 25: ...urrent 49 20 StatorTemperature RTD Lower 95 C upper 105 C 50 87 12 Differentialviaflux PU 10 INOM or less if 1A relay may be used summationCTs 50 27 IE 24 InadvertentEnergization 50 0 5A 10 INOM Overc...

Page 26: ...75 100 INOM GEN Definite Time 0 1 0 25 sec InadvertentEnergization Inst 200 INOM GEN 81 21 Over underfrequency Generator protection 57 62Hz 0 5s Island detection 59 61Hz 0 1s 87G 13 GeneratorPhase BE1...

Page 27: ...9 59 X X X X X X 59N 27 3N 59N 59P 4 4 4 60FL 60 X X X 67IE 67 X X 81 81O U 81O U X X X X X 87G 87G X 87N 67N 87UD 87T X 1 50 51G Indicates a relay that monitors a ground CT source 2 50 51N Indicates...

Page 28: ...54 2341 Fax 1 618 654 2351 BaslerElectricInternational P A E Les Pins 67319 Wasselonne Cedex FRANCE Phone 33 3 88 87 1010 Fax 33 3 88 87 0808 If you have any questions or need additionalinformation pl...

Search results

Summary of Contents for BE1-1051

Reviews:

Related manuals for BE1-1051

Brands by name

Popular brands

Basler BE1-1051, Application Manual

Search results

Summary of Contents for BE1-1051

Reviews:

Related manuals for BE1-1051

Brands by name

Popular brands