Multifunction Generator Relay - Taskertasker.us/source/sel/300g_im_07_06_sync_check.pdf · SEL-300G...

SEL-300G Multifunction Generator

Relay

Instruction Manual

20070607

*PM300G-01-NB*

SEL-300G Instruction Manual Date Code 20070607

TABLE OF CONTENTS

SECTION 4: SELOGIC CONTROL EQUATIONS..................................4-1

Introduction...................................................................................................................................4-1 SELOGIC Control Equation Overview .........................................................................................4-1 Relay Word Bits............................................................................................................................4-2

Relay Word Bit Operation Example—Neutral Time-Overcurrent Element 51NT...............4-2 Other Relay Word Bits..........................................................................................................4-3

SELOGIC Control Equations ........................................................................................................4-4 SELOGIC Control Equation Operators ..................................................................................4-4 All SELOGIC Control Equations Must Be Set.......................................................................4-7 SELOGIC Control Equation Limitations................................................................................4-7

Nondedicated SELOGIC Control Equation Variable Settings ......................................................4-8 Latch Control Switch Settings ......................................................................................................4-9

Latch Control Switch Application Ideas .............................................................................4-10 Local/Remote Generator Shutdown Setting Example ........................................................4-10 Latch Control Switch States Retained.................................................................................4-11 NOTE: Make Latch Control Switch Settings with Care ....................................................4-11

Trip Logic ...................................................................................................................................4-12 Set Trip................................................................................................................................4-14 Unlatch Trip ........................................................................................................................4-15

Generator Tripping .....................................................................................................................4-15 Generator Main Circuit Breaker Trip, TR1.........................................................................4-15 Generator Field Breaker Trip, TR2.....................................................................................4-16 Prime Mover Trip, TR3 ......................................................................................................4-16 Generator Lockout Relay Trip, TR4 ...................................................................................4-17 Factory Default Tripping Logic ..........................................................................................4-17 Program Output Contacts for Tripping ...............................................................................4-19

Close Logic .................................................................................................................................4-20 Set Close .............................................................................................................................4-20 Unlatch Close......................................................................................................................4-21 Settings Example.................................................................................................................4-21 Defeat the Close Logic........................................................................................................4-22 Program an Output Contact for Closing..............................................................................4-22

Synchronism Checking Function (Models 0300G2 and 0300G3)..............................................4-22 Element Description............................................................................................................4-22 Setting Calculation..............................................................................................................4-25 Element Operating Characteristics......................................................................................4-31

ER Control Equation...................................................................................................................4-34 Output Contact Control...............................................................................................................4-35

Factory Settings Example ...................................................................................................4-35 Operation of Output Contacts for Different Output Contact Types....................................4-35

Local Control Switches...............................................................................................................4-39 Local Control Switch Types................................................................................................4-40 Factory Settings Examples..................................................................................................4-42 Additional Local Control Switch Application Ideas ...........................................................4-43 Local Control Switch States Retained.................................................................................4-43

Remote Control Switches ...........................................................................................................4-44

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SELOGIC Control Equations 4-15


Unlatch Trip Once Relay Word bit TRIP is asserted to logical 1, it remains asserted at logical 1 until all the following conditions come true:

• Minimum Trip Duration Timer stops timing (logic output of the TDURD timer goes to logical 0)

• Output of TR1 gate deasserts to logical 0 • One of the following occurs:

− SELOGIC control equation setting ULTR1 asserts to logical 1 − the front-panel TARGET RESET button is pressed − the TAR R (Target Reset) command is executed via the serial port

The front-panel TARGET RESET button or the TAR R (Target Reset) serial port command primarily is used during testing. Use these to force the TRIP1 Relay Word bit to logical 0 if test conditions are such that setting ULTR1 does not assert to logical 1 to deassert the TRIP1 Relay Word bit automatically.

TRIP2 through TRIP4 operate similarly to TRIP1, as shown in Figure 4.6. The Relay Word bit TRIP is the OR condition of the four primary TRIP1 bits.

GENERATOR TRIPPING

Generator Main Circuit Breaker Trip, TR1 It is necessary to trip the Generator Main Circuit Breaker to isolate the generator from the system in response to many situations. The SEL-300G elements and logic used to detect each of the conditions are summarized in the following table.

Generator Tripping Condition Indicated or Detected By: Generator Manual Shutdown Local or Remote Bit Operation and Low-Forward

Power Condition Detected Generator Fault Neutral Overcurrent Elements, 51NT or 50N1T

100% Stator Ground Fault Elements, 64G1T or 64G2T Current Differential Elements, 87R or 87U Ground Current Differential Elements, 87N1T or 87N2T

Unbalance Current Tripping Negative-Sequence Overcurrent Element, 46Q2T Prolonged System Fault (Backup Tripping)

Voltage controlled Time-Overcurrent Element, 51CT Voltage Restrained Time-Overcurrent Element, 51VT Mho Phase Distance Elements, Z1P1T, Z1P2T

Generator Abnormal Operating Conditions

Overexcitation (Volts/Hertz) Element, 24C2T Reverse Power Element, 32P1T Out-of-Step Element, OOST Loss-of-Field Elements, 41Z1T or 40Z2T

Generator/System Frequency Conditions

Over/Underfrequency Elements, 81DnT

Generator Inadvertent Energization Inadvertent Energization Detected, INADT

4-16 SELOGIC Control Equations

Date Code 20070607 SEL-300G Instruction Manual

Generator Field Breaker Trip, TR2 It is necessary to trip the Generator Field Breaker if there is a generator fault or when tripping the generator manually. Field breaker tripping also is recommended for most abnormal operating conditions, excepting over/underfrequency element operation. The SEL-300G elements and logic used to detect field breaker tripping conditions are summarized in the table below. The field is left energized after over/underfrequency trips and negative-sequence overcurrent trips so if the situation can be remedied quickly, the generator can be put back into service quickly. Field Breaker Tripping Condition Indicated or Detected By:

Generator Manual Shutdown Local or Remote Bit Operation and Low-Forward Power Condition Detected

Generator Fault Neutral Overcurrent Elements, 51NT or 50N1T 100% Stator Ground Fault Elements, 64G1T or 64G2T Current Differential Elements, 87R or 87U Ground Current Differential Elements, 87N1T or 87N2T

Prolonged System Fault (Backup Tripping)

Voltage Controlled Time-Overcurrent Element, 51CT Voltage Restrained Time-Overcurrent Element, 51VT Mho Phase Distance Elements, Z1P1T, Z1P2T

Generator Abnormal Operating Conditions

Overexcitation (Volts/Hertz) Element, 24C2T Reverse Power Element, 32P1T Loss-of-Field Elements, 41Z1T or 40Z2T


Prime Mover Trip, TR3 A prime mover trip is performed first during a manual generator shutdown. The prime mover is also tripped in the event of a generator fault. Typically, the prime mover is not tripped in response to abnormal operating conditions. As with the field breaker trips, this is so that the generator can be reconnected quickly if the problem is corrected, avoiding the need for a time-consuming prime mover restart.

Prime Mover Tripping Condition Indicated or Detected By: Generator Manual Shutdown Local or Remote Bit Operation Generator Fault Neutral Overcurrent Elements, 51NT or 50N1T

100% Stator Ground Fault Elements, 64G1T or 64G2T Current Differential Elements, 87R or 87U Ground Current Differential Elements, 87N1T or 87N2T




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Generator Lockout Relay Trip, TR4 The generator lockout relay is tripped in the event of a generator fault. Typically, the lockout relay contacts prevent the generator breaker from being put back in service until the lockout relay has been reset. This would be done after the operation had been reviewed and, if necessary, the generator inspected to ensure that it could be returned to service safely. Lockout Relay Tripping Condition Indicated or Detected By:

Generator Fault Neutral Overcurrent Elements, 51NT or 50N1T 100% Stator Ground Fault Elements, 64G1T or 64G2T Current Differential Elements, 87R or 87U Ground Current Differential Elements, 87N1T or 87N2T



Generator Inadvertent Energization Inadvertent Energization Detected, INADT Generator Manual Shutdown Local or Remote Bit Operation and Low-Forward Power

Condition Detected

Factory Default Tripping Logic Review of the tables above shows that each of the controlled devices has tripping conditions in common. For instance, all of the devices are tripped in response to a generator fault. To simplify the relay settings, we have assigned nondedicated SELOGIC control equation variables to collect conditions that are used in more than one tripping equation. These settings are summarized and described below.

Generator Fault, Prolonged System Fault, Inadvertent Energization, and Manual Trips SELOGIC control equation variable 3 is used to indicate generator faults, prolonged system faults, inadvertent generator energization, and manual sequential trips:

SV3 = 64G1T + 64G2T + 51NT + 50N1T + 51CT + 51VT + INADT + LT1*32P2Ta aAdd +87R + 87U to the SV3 variable to obtain percentage restrained differential element tripping. Add +87N1T + 87N2T to the SV3 variable to obtain ground current differential tripping. Add +21P1T + 21P2T + 21C1T + 21C2T to obtain Zone 1 and Zone 2 distance tripping.

SELOGIC Control Equation Term

Asserts to Indicate:

64G1T Generator stator ground fault detected by neutral overvoltage. 64G2T Generator stator ground fault detected by third-harmonic voltage differential.51NT + 50N1T Ground fault detected by neutral time-overcurrent element or neutral

definite-time overcurrent element. 51CT + 51VT Prolonged system fault detected by voltage controlled phase time-

overcurrent or voltage restrained phase time-overcurrent. INADT Inadvertent generator energization detected. LT1*32P2T Generator manual trip through latch bit LT1 and low-forward power element

32P2T.



Generator Abnormal Operating Conditions SELOGIC control equation variable 4 is used to indicate generator abnormal operating conditions:

SV4 = 24C2T + 32P1T + 40Z1T + 40Z2T

SELOGIC Control Equation Term


24C2T Generator overexcitation detected by composite volts/hertz element. 32P1T Generator reverse power condition detected. 40Z1T + 40Z2T Generator loss-of-field detected by Zone 1 or Zone 2 loss-of-field

element (SV1T term also may be added if positive offset Zone 2 is applied. See Section 2: Relay Element Settings.)

Generator Main Circuit Breaker Tripping Settings As described above, TR1 is used to define the generator main circuit breaker tripping conditions:

TR1 = SV3 + SV4 + 46Q2T + 81D1T + 81D2T + OOST

If out-of-step tripping is desired via TR2, TR3, or TR4, modify the equations for TR2, TR3, and TR4 to include Relay Word bit OOST.

TR1 SELOGIC Control Equation Term


SV3 Generator fault detected by elements set in SV3 control equation, defined above.

SV4 Generator abnormal operating condition detected by elements set in SV4 SELOGIC control equation, defined above.

46Q2T Generator current unbalance trip. 81D1T + 81D2T Generator definite-time underfrequency trip through 81D1T or

81D2T elements.

The trip signal can be released after the generator main breaker is open, as indicated by the three-pole open, 3PO, Relay Word bit.

ULTR1 = 3PO

Generator Field Circuit Breaker Tripping Settings As described above, TR2 is used to define the generator field circuit breaker tripping conditions:

TR2 = SV3 + SV4



SV3 Generator fault detected by elements set in SV3 SELOGIC control equation, defined above.

SV4 Generator abnormal operating conditions detected by elements set in SV4 SELOGIC control equation, defined above.



The trip signal can be released after the tripping conditions are no longer present, as indicated by the inverse of the TR2 tripping condition:

ULTR2 = !TR2

Prime Mover Tripping Settings As described above, TR3 is used to define the prime mover tripping conditions:

TR3 = SV3 + LT1




LT1 Manual shutdown initiated by local bit LB1 or remote bit RB1.


ULTR3 = !TR3

Generator Lockout Relay Tripping Settings As described above, TR4 is used to define the generator lockout relay tripping conditions:

TR4 = SV3





ULTR4 = !TR

Program Output Contacts for Tripping In the factory settings, the results of the trip logic in Figure 4.6 are routed to output contact OUT101, OUT102, OUT103, and OUT104 with the following SELOGIC control equation settings:

OUT101 = TRIP1 Generator Main Circuit Breaker Tripping Contact OUT102 = TRIP2 Generator Field Circuit Breaker Tripping Contact OUT103 = TRIP3 Prime Mover Tripping Contact OUT104 = TRIP4 Generator Lockout Relay Tripping Contact

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CLOSE LOGIC The close logic in Figure 4.8 provides flexible circuit breaker closing with SELOGIC control equation settings:

52A (breaker status) CLEN (CLOSE enable) CL (close conditions, other than CLOSE command) ULCL (unlatch close conditions, other than circuit breaker status)

ULCL

CLOSE

SerialPort

Command

CL

CLOSE

52A

CLEN

SELOGICSetting

0

CLSD

DWG: M300G066

SELOGICSetting

ResetTimer

Figure 4.8: Close Logic

Set Close If all the following are true:

• The unlatch close condition is not asserted (ULCL = logical 0) • The circuit breaker is open (52A = logical 0) • Closing is enabled (CLEN = logical 1)

Then the CLOSE Relay Word bit can be asserted to logical 1 if any one of the following occurs: • The serial communications port CLOSE command is executed • SELOGIC control equation setting CL goes from logical 0 to logical 1 (rising edge

transition)

If a serial port CLOSE command is executed or CL goes from logical 0 to logical 1 while the CLEN SELOGIC control equation is logical 0, the relay waits for CLSD close dwell time seconds for CLEN to assert. If CLEN asserts before CLSD expires, the CLOSE Relay Word bit asserts to logical 1. If CLEN does not assert before CLSD expires, the CLOSE Relay Word bit does not assert and the logic is reset. This logic permits the CLEN SELOGIC control equation to supervise relay initiated closes. See the Settings Example below.



Unlatch Close If the CLOSE Relay Word bit is asserted at logical 1, it stays asserted at logical 1 until one of the following occurs:

• The unlatch close condition asserts (ULCL = logical 1) • The circuit breaker closes (52A = logical 1) • The close enable deasserts (CLEN = logical 0)

Settings Example Suggested settings for the close logic SELOGIC control equation settings are:

52A = IN101 CL = LB2 Permits front-panel close operations via Local bit LB2, OR

with INxxx (e.g., IN103) connected to local control switch or SCADA close signal as desired.

CLEN = !SV6T + CLOSE Prevents a second close for 30 seconds and seals-in CLEN. Use !SV6T*25C + CLOSE for synch-check supervised closing.

ULCL = TRIP + SV5T Unlatches CLOSE if relay trips or if CLOSE is asserted for more than 1 second.

• • •

SV5 = CLOSE SV5PU = 1.00 SV5DO = 0.00 SV6 = CLOSE SV6PU = 0.00 SV6DO = 30.00

The factory setting for the Close Dwell Timer setting is: CLSD = 0.00 s

A longer CLSD timer setting would be applied if the close logic should remain armed for a time while the generator is synchronized (e.g., synch-check supervised closing).

See the Settings Sheets at the end of Section 6: Enter Relay Settings for setting ranges.

Set Close With the suggested settings, SELOGIC control equation setting CL is set with local bit LB2. Local bit LB2 closes directly (operates as a manual close switch via the front panel). See Local Control Switches in this section and Front-Panel Local Control in Section 9: Front-Panel Operation for more information on local control.

Unlatch Close With the suggested settings, SELOGIC control equation setting ULCL is set by the TRIP Relay Word bit. This prevents the CLOSE Relay Word bit from being asserted any time the TRIP Relay Word bit is asserted (TRIP takes priority). See Trip Logic in this section.



SELOGIC control equation setting 52A is set with optoisolated input IN101. Input IN101 is connected to a 52a circuit breaker auxiliary contact. When a closed circuit breaker condition is detected, the CLOSE Relay Word bit is deasserted to logical 0. Setting 52A can handle a 52a or 52b circuit breaker auxiliary contact connected to an optoisolated input.

Defeat the Close Logic If SELOGIC control equation close enable setting CLEN is set with logical 0 (CLEN = 0), then the close logic is inoperable.

Program an Output Contact for Closing In the factory settings, the result of the close logic in Figure 4.8 is routed to output contact OUT105 with the following SELOGIC control equation:

OUT105 = CLOSE

SYNCHRONISM CHECKING FUNCTION (MODELS 0300G2 AND 0300G3)

Element Description

Functional Description A synchronism checking relay is usually used to verify that the generator frequency, voltage magnitude, and phase angle match the system frequency, voltage magnitude, and phase angle before allowing the generator breaker to be closed. The SEL-300G2 and SEL-300G3 Relays provide a built-in synchronism checking function. The relay measures system voltage using the VS voltage input, which you should connect to the secondary of a phase-to-ground or phase-to-phase connected VT on the system side of the generator circuit breaker. If a phase-to-phase connected VT is applied, it should be connected between A- and B-phase or between B- and C-phase. See Section 5: Installation for additional connection details.

The relay measures the system conditions through the VS input. The relay measures generator frequency using the VA or VAB input. Other generator voltage conditions are determined using the voltage selected by the SYNCP setting, set to match the VS input connection. If the slip frequency (frequency difference between the generator and system) is within settable bounds, both voltage magnitudes are within settable bounds, and the phase-angle difference is desirable, the relay synchronism check function can permit a CLOSE signal to be issued by the SEL-300G or can close an output contact to supervise an external close condition.

The relay takes into account the breaker closing time and the present slip frequency to issue a close signal timed to have the system and generator at a settable angle difference when the breaker closes.

If a generator step-up transformer is connected between the generator terminals and the open generator breaker, the SEL-300G can account for a ±30° phase shift introduced by the transformer connections without using auxiliary transformers.

In the event that the generator breaker is slow to close, the generator and system voltages might drift to a phase angle that is unsafe for closing before the breaker closes. In this event, the relay detects that the phase angle between the generator and system voltages is above a safe closing

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Remote Bit States Retained When Settings Changed or Active Setting Group Changed The state of each remote bit (Relay Word bits RB1 through RB16) is retained if relay settings are changed (for the active setting group or the other setting group) or the active setting group is changed. If a remote control switch is in the ON position (corresponding remote bit is asserted to logical 1) before a setting change or an active setting group change, it comes back in the ON position (corresponding remote bit is still asserted to logical 1) after the change. If a remote control switch is in the OFF position (corresponding remote bit is deasserted to logical 0) before a settings change or an active setting group change, it comes back in the OFF position (corresponding remote bit is still deasserted to logical 0) after the change.

FRONT-PANEL DISPLAY CONFIGURATION The rotating default display on the relay front panel replaces indicating panel meters and lights. Traditional panel meters indicate generator electrical quantities such as:

• phase current • phase voltage • generator output power • generator frequency

Traditional indicating panel lights are turned on and off by circuit breaker auxiliary contacts, front-panel switches, SCADA contacts, etc. They indicate such conditions as:

• circuit breaker open/closed • protection elements enabled/disabled

Traditional Indicating Panel Meters Traditional indicating panel meters are wired to ac current and voltage transformers in series or parallel with SEL-300G ac inputs. The panel meters then measure and display desired quantities, such as current magnitude, voltage magnitude, generator frequency, generator output power, etc.

Traditional Indicating Panel Meters Replaced with Rotating Meter Display The indicating panel meters are not needed if the rotating default display feature in the SEL-300G is applied. The relay already is measuring the desired quantities to a high degree of accuracy. Simply configure the front-panel display settings to enable the automatic display of real-time measured quantities.

To enable real-time display of measured quantities, use the serial port SET G command or front-panel SET GLOBAL setting entry functions (see Section 6: Enter Relay Settings and Section 10: Serial Port Communications and Commands). Enabled real-time measurements are shown along with the text display points on the SEL-300G front-panel display on a 2-second rotation (see Rotating Default Display in Section 9: Front-Panel Operation for more specific operation information).



The following factory settings examples enable rotating display of phase currents, phase-to-phase voltages, generator output power, generator frequency, and station dc voltage.

Front-Panel Current Display (Y, N) FP_I = Y Setting to Y enables rotating display of measured generator phase and neutral currents, scaled in primary amperes.

Front-Panel Phase-to-Phase Voltage Display (Y, N) FP_VPP = Y Setting to Y enables rotating display of measured generator phase-to-phase voltages and neutral voltage, scaled in primary kilovolts.

Front-Panel Phase Voltage Display (Y, N) FP_VP = N Setting to Y enables rotating display of measured generator phase and neutral voltages, scaled in primary kilovolts.

Front-Panel Power Display (Y, N) FP_MW = Y Setting to Y enables rotating display of measured generator real and reactive three-phase power, scaled in primary megawatts and megavars, and the present generator output power factor.

Front-Panel Frequency Display (Y, N) FP_FR = Y Setting to Y enables rotating display of measured generator frequency in hertz and measured dc battery voltage in volts.

Front-Panel Current Differential Display (Y, N) FP_87 = N Setting to Y enables rotating display of measured generator differential input phase currents, scaled in primary amperes (available only when relay is equipped with differential current inputs).

Additional detailed meter data is also available using the front-panel METER pushbutton or serial port METER commands.

Traditional Indicating Panel Lights Figure 4.24 shows traditional indicating panel lights wired in parallel with SEL-300G optoisolated inputs. Input IN101 provides generator main circuit breaker status to the relay, and input IN102 indicates generator field circuit breaker status.

DWG: M300G072

Field BreakerAuxiliary Contact

52a

SEL-300G

(+)

IN102Gen MainBreakerClosed

FieldBreakerClosed

(-)

IN101

Figure 4.24: Traditional Panel Light Installations



Circuit Breaker Status Indication In Figure 4.24, the GEN MAIN BREAKER CLOSED panel light illuminates when the generator main circuit breaker 52a auxiliary contact is closed. When the 52a circuit breaker auxiliary contact is open, the GEN MAIN BREAKER CLOSED panel light extinguishes, and it is understood that the breaker is open. Operation is similar for the field breaker auxiliary contact.

Traditional Indicating Panel Lights Replaced with Rotating Text Display The indicating panel lights are not needed if the rotating text display feature in the SEL-300G is used. Figure 4.25 shows the elimination of the indicating panel lights by using the rotating text display.

DWG: M300G073

Field BreakerAuxiliary Contact

52a

SEL-300G

(+)

IN102

(-)

IN101Gen Breaker ClosedField Breaker Closed

Figure 4.25: Rotating Text Display Replaces Traditional Panel Light Installations

There are sixteen (16) of these text displays available in the SEL-300G. Each text display has two complementary screens (e.g., GEN BKR CLOSED and GEN BKR OPEN) available.

General Operation of Rotating Text Display Settings SELOGIC control equation display point setting DPn (n = 1 through 16) controls the display of corresponding, complementary text settings:

DPn_1 (displayed when DPn = logical 1) DPn_0 (displayed when DPn = logical 0)

Make each text setting through the serial port using the command SET G. View these text settings using the serial port command SHO G (see Section 6: Enter Relay Settings and Section 10: Serial Port Communications and Commands). These text settings are displayed on the SEL-300G front-panel display on a 2-second rotation (see Rotating Default Display in Section 9: Front-Panel Operation for more specific operation information).

The following factory settings examples use optoisolated inputs IN101 and IN102 in the display point settings. Local bits (LB1 through LB16), latch bits (LT1 through LT16), remote bits (RB1 through RB16), setting group indicators (SG1 and SG2), and any other combination of Relay Word bits in a SELOGIC control equation setting also can be used in display point setting DPn.

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