ag_ag2004-12_20040823

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SCHWEITZER ENGINEERING LABORATORIES2350 NE Hopkins Court • Pullman, WA • 99163-5603 • USAPhone: (509) 332-1890 • Fax: (509) 332-7990E-mail: [email protected] • Internet: www.selinc.com

Application Guide Volume III AG2004-12

Implementation of Voltage, Frequency,

and Power Elements in the SEL-451 RelayUsing SELOGIC Control Equations

Jacob Reidt

INTRODUCTION

The SEL-451 Relay has the speed, power, and flexibility to combine the control and protection ofmany substation devices into one economical system. Programmable logic and math operatorsavailable in the SEL-451 allow the relay to implement a number of functions common todistribution relaying: under- and overvoltage elements, under- and overfrequency elements, andpower elements.

Phase under- and overvoltage elements are useful for the creation of a number of protection andcontrol schemes such as:

• Torque control for the overcurrent protection.

• Hot-bus (line), dead-bus (line) recloser control.

• Blown transformer high-side fuse detection logic.

• Trip/alarm or event report triggers for voltage sags and swells.

• Undervoltage load shedding scheme.

• Control schemes for capacitor banks.

Independently set positive-, negative-, and zero-sequence voltage elements provide for additionalprotection and control applications including transformer bank single-phase trip schemes anddelta-load back-feed detection scheme for dead-line recloser control.

Under- and overfrequency elements detect true frequency disturbances. Use a time-delayedoutput of these elements to shed load or trip local generation. Phase undervoltage supervisionprevents undesired frequency element operation during faults. Use multiple under- andoverfrequency levels to implement an internal multistage frequency trip/restore scheme at eachbreaker location. This avoids the cost of wiring a complicated trip and control scheme from aseparate frequency relay.

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2 SEL Application Guide 2004-12 Date Code 20040823

Single-phase and three-phase power elements can be enabled to detect real or reactive power inthe forward or reverse directions. With SELOGIC® control equations, the power elements provide

a wide variety of protection and control applications. Typical applications are as follows:

• Overpower and/or underpower protection and control.

•Reverse power protection and control.

• VAR control for capacitor banks.

PROTECTION ELEMENTS

Programmable logic and math operators available in the SEL-451 allow the relay to implementthe protection elements outlined in the previous section.

Method

Analog registers hold filtered measurements taken from the SEL-451 potential and current inputs.

The SEL-451 has six ac current inputs and six ac voltage inputs available for protection, allowingfor a number of different connections to the power system. This application guide was writtenusing a single circuit breaker connection (see the AC/DC Connection Diagrams subsection inSection 2 of the SEL-451 User’s Guide).

Protection Math Variables and Automation Math Variables can hold setting values or measuredanalog quantities. In this application guide, we use the Protection Math Variables to holdmeasured analog quantities or mathematically adjusted analog quantities, and the AutomationMath Variables are used to hold constants used as element settings. Protection Math Variablesare processed every relay processing interval, so these stored analog quantities accurately reflectthe system parameters. Automation Math Variables are processed as time permits (but at leastonce per second). Automation Math Variables are therefore ideal for storing fixed setting values,whereas, Protection Math Variables are better suited for storing quantities that can change quicklyor must be rapidly evaluated.

Driven by the free-form logic settings, the SEL-451 produces logic results through mathmanipulations and comparisons of the measured analog signals to settings. The relay can usethese logic results in intermediate logic, such as Protection SELOGIC Variables or ProtectionConditioning Timers. Math comparisons, manipulations, and logic developments occur in theSEL-451 free-form logic setting area. The logic results generated in this free-form area can beprogrammed to operate the trip equation, output contacts, front-panel targets, and front-panelLEDs. The following sections explain how to build these logic settings.

Analog Inputs

Table 1: Analog Quantities Used

Label Description Units

VAFIM, VBFIM, VCFIM Phase filtered instantaneous voltage magnitude V secondary

3V0FIM Zero-sequence instantaneous voltage magnitude V secondary

3V2FIM Negative-sequence instantaneous voltage magnitude V secondary

V1FIM Positive-sequence instantaneous voltage magnitude V secondary

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Date Code 20040823 SEL Application Guide 2004-12 3

Label Description Units

LIAFIM, LIBFIM, LICFIM Phase filtered instantaneous current magnitude A secondary

PA_f, PB_f, PC_f Phase fundamental real power MW primary

QA_f, QB_f, QC_f Phase fundamental reactive power MVAR primary

3P_f Three-phase fundamental real power MW primary3Q_f Three-phase fundamental reactive power MVAR primary

FREQ Measured system frequency Hz

Voltage Elements

Table 2: Voltage Elements Settings and Settings Ranges

Device

Voltage Element

(Relay Word Bits)a

Operating

Voltage Pickup Settingb /Range

c

See

Figure

PSV08 VA PSV09 V

B

PSV10 VC

27

PSV11 := PSV08 ANDPSV09 AND PSV10

AMV0050.00–300.00 V secondary

PSV01 VA

PSV02 VB

PSV03 VC

PSV04 := PSV01 ANDPSV02 AND PSV03

AMV0010.00–300.00 V secondary

Figure 1

PSV05 3V0 AMV002

0.00–300.00 V secondary

PSV06 V2 AMV003


59

PSV07 V1 AMV004


Figure 2

a Example Protection SELOGIC Variables (PSVs) are shown here. The SEL-451 has 64 PSVs tochoose from (PSV01–PSV64). Select these variables to avoid unintentional duplication.

b Example Automation Math Variables (AMVs) are shown here. The SEL-451 has 256 AMVs tochoose from (AMV001–AMV256). Select these variables to avoid unintentional duplication.

c Pickup setting ranges are not defined in the SEL-451. The pickup settings are Automation MathVariables that are not constrained by any boundary conditions. The ranges given are suggestionsbased on the SEL-351-7 and SEL-351S-7 ranges for the corresponding pickup setting. A valueexceeding this range could be assigned to the corresponding Automation Math Variable ifnecessary.

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PSV08

(27A)

PSV09

(27B)

PSV10

(27C)

PSV11

(3P27)

PSV01

(59A)

PSV02

(59B)

PSV03

(59C)

PSV04

(3P59)

AMV005

(27PP)

PMV01 (V A

)

PMV02 (VB)

PMV03 (VC)

AMV001

(59PP)

PSV01 := PMV01 > AMV001

PSV02 := PMV02 > AMV001

PSV03 := PMV03 > AMV001

PSV04 := PSV01 AND PSV02 AND PSV03

PSV08 := PMV01 < AMV005

PSV09 := PMV02 < AMV005

PSV10 := PMV03 < AMV005

PSV11 := PSV08 AND PSV09 AND PSV10

Figure 1: Single-Phase and Three-Phase Voltage Elements

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AMV002

(59NP)

PSV05

(59N)

PSV06

(59Q)

PSV07

(59V1)

AMV003(59QP)

AMV004

(59V1P)

PMV04 (3V0)

PMV05 (V2)

PMV06 (V1)

+

+

+

PSV05 := PMV04 > AMV002

PSV06 := PMV05 > AMV003

PSV07 := PMV06 > AMV004

Figure 2: Sequence Voltage Elements

Accuracy

Pickup: ±2 V and ±5% of setting

Transient Overreach: ±5% of setting

Voltage Element Operation

Note that the voltage elements are a combination of undervoltage (Device 27) and overvoltage(Device 59) type elements. Undervoltage elements (Device 27) assert when the operating voltagegoes below the corresponding pickup setting. Overvoltage elements (Device 59) assert when theoperating voltage goes above the corresponding pickup setting.

Undervoltage Element Operation Example

Refer to Figure 1 (top of the figure).

Pickup setting AMV005 is compared to the magnitudes of the individual phase voltages VA, V

B,

and VC. The logic outputs in Figure 1 are the following Relay Word bits:

PSV08 = 1 (logical 1), if VA < pickup setting AMV005

= 0 (logical 0), if VA ≥ pickup setting AMV005

PSV09 = 1 (logical 1), if VB < pickup setting AMV005

= 0 (logical 0), if VB ≥ pickup setting AMV005

PSV10 = 1 (logical 1), if VC < pickup setting AMV005

= 0 (logical 0), if VC ≥ pickup setting AMV005

PSV11 = 1 (logical 1), if all three Relay Word bits PSV08, PSV09, and PSV10 are asserted(PSV08 = 1, PSV09 = 1, and PSV10 = 1)

= 0 (logical 0), if at least one of the Relay Word bits PSV08, PSV09, and PSV10 isdeasserted (e.g., PSV08 = 0)

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Overvoltage Element Operation Example

Refer to Figure 1 (bottom of the figure).

Pickup setting AMV001 is compared to the magnitudes of the individual phase voltages VA, V

B,

and VC. The logic outputs in Figure 1 are the following Relay Word bits:

PSV01 = 1 (logical 1), if VA > pickup setting AMV001

= 0 (logical 0), if VA ≤ pickup setting AMV001

PSV02 = 1 (logical 1), if VB > pickup setting AMV001

= 0 (logical 0), if VB ≤ pickup setting AMV001

PSV03 = 1 (logical 1), if VC > pickup setting AMV001

= 0 (logical 0), if VC ≤ pickup setting AMV001

PSV04 = 1 (logical 1), if all three Relay Word bits PSV01, PSV02, and PSV03 are asserted(PSV01 = 1, PSV02 = 1, and PSV03 = 1)

= 0 (logical 0), if at least one of the Relay Word bits PSV01, PSV02, and PSV03 is

deasserted (e.g., PSV01 = 0)

Voltage Element Analog Quantity Metering

Protection Math Variables were chosen to store the measured analog quantities in order to allow

for direct metering of the measure secondary voltages by utilizing the MET PMV A command.Should direct metering not be necessary for commissioning practices, the voltage comparisonlogic can be made using the analog quantities, e.g., PSV01 := VAFIM > AMV001.

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Frequency Elements

The SEL-451 relay measures power system frequency based on fixed rate sampled voltages. Therelay measures the time between zero crossings, filters the time measurement, and processes themeasurement with an algorithm to remove line anomalies.

The SEL-451 automatically provides necessary frequency tracking while there is no pole opencondition, there is no loss-of-potential condition, and there is no fault.

Frequency tracking in the SEL-451 is limited by the specified range: 40–65 Hz. Slew rates of10.0 Hz/s or greater also disable frequency tracking. Measured system frequency (analogquantity FREQ) reverts to the nominal frequency setting value (Global setting NFREQ) whenfrequency tracking thresholds have been exceeded.

Frequency Element Settings

AMV021

(27B81P)

PMV01 (V A)

PMV02 (VB)

PMV03 (VC)

ToFrequencyElementLogic

PCT01Q

(27B81)

PSV21 := PMV01 < AMV021 OR PMV02 < AMV021

PCT01IN := PSV21

OR PMV03 < AMV021

PSV21

Figure 3: Undervoltage Block for Frequency Elements

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Undervoltage Condition

q

ASV021

AMV022

PCT01Q

(27B81)

PSV22

(81D)Over-Frequency

Under-

Frequency

(MeasuredSystem

Frequency

in HZ)

PMV21

PCT02PU(81DD)

0

PCT02Q

(81DT)

PSV22 := (ASV021 AND (PMV21 > AMV022) OR NOT (ASV021)

AND (PMV21 <= AMV022)) AND NOT (PCT01Q)

PCT02IN := PSV22

(81DP)

q From Figure 3

Figure 4: Frequency Element

Table 3: Frequency Elements Settings and Settings Ranges

Setting Definition Range

ASV021 Select frequency element 1 (Overfrequency), 0 (Underfrequency)

AMV021 Undervoltage frequency elementblock pickup


AMV022 Frequency element pickup 40.10–64.90 Hz

AMV023 Frequency element time delay 2.00–16000.00 cycles

Table 4: Frequency Element Relay Word Bits

Relay Word Bit Description

PCT01Q Undervoltage frequency element block

PCT02Q Frequency element

Accuracy

Pickup: ± 0 .01 Hz

Create Over- and Underfrequency Elements

Refer to Figure 4.

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Overfrequency Element

For example, make settings:

ASV021 := 1 (select overfrequency element)

AMV022 := 61.25 (frequency element pickup)

The overfrequency part of the frequency element logic is enabled. PSV22 operates as aninstantaneous overfrequency element. For actual protection, SEL recommends the use ofconditional timer output PCT02Q.

Underfrequency Element

For example, make settings:

ASV021 := 0 (select underfrequency element)

AMV022 := 59.65 (frequency element pickup)

The underfrequency part of the frequency element logic is enabled. PSV22 operates as aninstantaneous underfrequency element. For actual protection, SEL recommends the use ofconditional timer output PCT02Q.

Frequency Element Operation

Refer to Figure 4.

Overfrequency Element Operation

With the previous overfrequency element example settings, if the system frequency is less than orequal to 61.25 Hz (AMV022 = 61.25 Hz), the frequency element outputs:

PSV22 = logical 0

If the system frequency is greater than 61.25 Hz (AMV022 = 61.25 Hz), the frequency elementoutputs:

PSV22 = logical 1

Underfrequency Element Operation

With the previous underfrequency element example settings, if the system frequency is less thanor equal to 59.65 Hz (AMV022 = 59.65 Hz), the frequency element outputs:

PSV22 = logical 1

If the system frequency is greater than 59.65 Hz (AMV022 = 59.65 Hz), the frequency elementoutputs:

PSV22 = logical 0

Frequency Element Voltage Control

Refer to Figure 3 and Figure 4.

The frequency element is controlled by the undervoltage element conditioning timer PCT01.Relay Word bit PCT01Q asserts to logical 1 and blocks the frequency element operation if any

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voltage (VA, V

B, or V

C) goes below voltage pickup AMV021. This control prevents erroneous

frequency element operation following fault inception.

Power Elements

Either single-phase power elements or three-phase power elements may be enabled. Each power

element can be set to detect real power or reactive power in the forward or reverse direction. Thepower element type settings are made in reference to the load convention:

+WATTS: positive or forward real power–WATTS: negative or reverse real power+VARS: positive or forward reactive power (lagging)–VARS: negative or reverse reactive power (leading)

Power Elements Settings

Table 5: Single-Phase Power Element Settings and Setting Ranges

Settings Definition Range

ASV041 Power element type 1 (Watt), 0 (Var)

AMV041 Power element direction 1.0 (+), –1.0 (–)

AMV042 Power element pickup 2.00–13000.00 VA secondary, single-phase

AMV043 Power element time delay 0.0–16000.00 cycles

Table 6: Three-Phase Power Element Settings and Setting Ranges

Settings Definition Range

ASV042 Power element type 1 (Watt), 0 (Var)

AMV044 Power element direction 1.0 (+), –1.0 (–)

AMV045 Power element pickup 6.00–39000.00 VA secondary, three-phase

AMV046 Power element time delay 0.00–16000.00 cycles

Table 7: Single-/Three-Phase Power Element Relay Word Bits

Relay Word Bits Description

PCT03Q A-phase power element

PCT04Q B-phase power element

PCT05Q C-phase power element

PCT06Q Three-phase power element

Power Element Calculations

The numeric method used in the power elements uses 10-cycle average line-to-neutral voltageand phase current quantities. Each phase is calculated separately, with the resulting power

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quantities subject to the minimum voltage and current tests shown in the lower half of Figure 5. The three-phase power is the sum of the single-phase powers.

Power Element Logic Operation

_

+

_ +

_

+

_

+

PMV01 (|V A|)10 V sec

|I A

|

0.1 • INOM

PMV01 (|V A

|)

40 V sec

|I A

|

0.01 • INOM

_

+

10-cycle

average

Phase A

Reactive Power

10-cycle

averagePhase A

Real Power

Switch in this

position if

ASV041 := 1

multiply by -1

• (–1)

Switch in this

position if

ASV041 := 0

Switch in this

position if

AMV041 := 1.0

Switch in this

position if

AMV041 := –1.0

Single-phase VA pri

AMV054

Sufficient

Signal

PSV47

INOM

= 1 A sec or 5 A sec

Repeat for Phases B and C

PSV41

PCT03Q

(PWRA)

PCT03PU(PWRD)

0

PSV41 := PMV01 > 40 AND LIAFIM > AMV056

OR PMV01 > 10 AND LIAFIM > AMV057

PSV47 := (PMV41 > AMV054) AND PSV41

PCT03IN := PSV47

PMV41

(PWRP pri)

Figure 5: Single-Phase Power Element Logic (+VARS Example Shown)

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10 Cycle

Average

Real Power

(Three-Phase)

Reactive Power

(Three-Phase)

1

2

PSV50multiply by –1

AMV055(3PWRP pri)

Switch A Switch B

2• (–1)

1

Sufficient

Signal

PSV46

PMV01 (⏐V A⏐)

PMV02 (⏐VB⏐)

PMV03 (⏐VC⏐)

10 V

⏐I A⏐

⏐IB⏐

0.1 • INOM

40 V

⏐IC⏐

⏐IB⏐

⏐I A⏐

⏐IC⏐

PMV01 (⏐V A⏐)

PMV02 (⏐VB⏐)

PMV03 ( |VC| )

0.01 • INOM

INOM = 1 A sec or 5 A sec

AMV044

ASV042Switch APosition

Switch BPosition

–1.0

1.0

10

12

2

1

PMV44

PCT06Q

(3PWR)

PSV45

PSV44

AND LIAFIM > AMV056 AND LIBFIM > AMV056

AND LICFIM > AMV056

PSV44 := PMV01 > 40 AND PMV02 > 40 AND PMV03 > 40

PSV45 := PMV01 > 10 AND PMV02 > 10 AND PMV03 > 10 AND LIAFIM > AMV057 AND LIBFIM > AMV057

AND LICFIM > AMV057PSV46 := PSV44 OR PSV45PSV50 := PMV44 > AMV055 AND PSV46PCT06IN := PSV50

PCT06PU(PWRD)

0

Figure 6: Three-Phase Power Element Logic

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Reactive

Power

Real

Power

Power

Element

Pickup

Power

Element

Pickup

Reactive

Power

Power

Element

Pickup

Power

Element

Pickup

Real

Power

52

SEL-

451

Set as Reactive Power Element

reverse

(leading)

forward

(lagging)

52

SEL-

451

Set as Real Power Element

reverse forward

-WATTS +WATTS

-VARS

+VARS

Figure 7: Power Element Operation in the Real/Reactive Power Plane

Figure 5 shows an example for +VARS.

In Figure 7, if the Phase A reactive power level is above the power element pickup threshold,

Relay Word bit PSV47 asserts (PSV47 = logical 1), subject to the “sufficient signal” conditions.

The “sufficient signal” conditions in Figure 5 require at least 1 percent nominal current if thecorresponding phase voltage is greater than 40 V secondary. If the voltage is between 10 and40 V secondary, at least 10 percent nominal current is required. This check has been added to thelogic in order to replicate the functionality of the SEL-351-7. Should individual practice dictate adifferent constraint, the logic (PSV41, PSV42, PSV43, and PSV46) can be modified as necessary.

Pickup setting AMV042 is always a positive number value (see Table 5). Thus, if –WATTS or–VARS are chosen with settings AMV041 and ASV041, the corresponding real or reactive powervalues have to be multiplied by –1 so that element PSV47 asserts for negative real or reactivepower.

Power Element Time Delay Considerations

Power elements are time-delayed using Protection Conditioning Timers (PCTs). The SEL-451Relay has 16 PCTs to choose from (PCT01–PCT16). Select these timers to avoid unintentionalduplication. For protection applications involving the power elements, SEL recommends aminimum time delay of 5.00 cycles for general applications. The classical power calculation is aproduct of voltage and current, to determine the real and reactive power quantities. During asystem disturbance, because of the high sensitivity of the power elements, the changing systemphase angles and/or frequency shifts may cause transient errors in the power calculation.

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Accuracy

Single-Phase Power Elements

Pickup: ±0.025 A • (voltage secondary) and ±5% of setting at unity power factor (for +WATTSor –WATTS) or power factor = 0 (for +VARS or –VARS) (5 A nominal phase current)

±0.005 A • (voltage secondary) and ±5% of setting at unity power (for +WATTS or–WATTS) or power factor = 0 (for +VARS or –VARS) (1 A nominal phase current)

Three-Phase Power Elements

Pickup: ±0.025 A • (voltage secondary) and ±5% of setting at unity power factor (for +WATTSor –WATTS) or power factor = 0 (for +VARS or –VARS) (5 A nominal phase current)

±0.005 A • (voltage secondary) and ±5% of setting at unity power (for +WATTS or–WATTS) or power factor = 0 (for +VARS or –VARS)(1 A nominal phase current)

Settings

Protection and Automation Free-Form Logic Settings

This is where the SEL-451 uses the set free-form logic to implement voltage comparisons,frequency comparisons, power calculations, and logic operation.

Variable Assignment Within the SEL-451 Relay

See Table 13 for a detailed listing of the SEL-351-7 Relay Word bit allocation used within theSEL-451 for this application.

FILTERING

The SEL-451 provides advanced filtering. This application uses the available fundamentalquantities with all harmonics removed.

CONCLUSION

Through use of the programmable free-form logic area, the SEL-451 provides for the creation ofcertain protection elements common in the protection and control of distribution systems. TheSEL-451 uses math variable comparison, manipulation, and logic equations to implementprotection functions.

In addition, the extensive monitoring and recording features of the SEL-451 provide improvedperformance monitoring and use of substation equipment.

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SUPPLEMENTAL TABLES

Table 8: Protection Free-Form Logic Settings (SET L Command)

Protection Code #Commentsa

PMV01 := VAFIM VA magnitude

PMV02 := VBFIM VB magnitude

PMV03 := VCFIM VC magnitude

PMV04 := 3V0FIM 3V0 magnitude

PMV05 := 3V2FIM / 3 V2 magnitude

PMV06 := V1FIM V1 magnitude

PSV01 := PMV01 > AMV001 59A

PSV02 := PMV02 > AMV001 59B

PSV03 := PMV03 > AMV001 59C

PSV04 := PSV01 AND PSV02 AND PSV03 3P59

PSV05 := PMV04 > AMV002 59N

PSV06 := PMV05 > AMV003 59Q

PSV07 := PMV06 > AMV004 59V1

PSV08 := PMV01 < AMV005 27A

PSV09 := PMV02 < AMV005 27B

PSV10 := PMV03 < AMV005 27C

PSV11 := PSV08 AND PSV09 AND PSV10 3P27

PMV21 := FREQ Frequency magnitude

PSV21 : = PMV01 < AMV021 OR PMV02 <AMV021 OR PMV03 < AMV021

Undervoltage frequencyelement block

PCT01PU := 0.0

PCT01DO := 5.0

PCT01IN := PSV21 Undervoltage frequencyelement block dropout timer

PSV22 := (ASV021 AND (PMV21 >

AMV022) OR NOT(ASV021) AND (PMV21<= AMV022)) AND NOT (PCT01Q)

81D

PCT02PU := AMV023 81DD

PCT02DO := 0.0

PCT02IN := PSV22

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PSV41 := PMV01 > 40 AND LIAFIM >AMV056 OR PMV01 > 10 AND LIAFIM >AMV057

Sufficient Signal A-phase

PSV42 := PMV02 > 40 AND LIBFIM >AMV056 OR PMV02 > 10 AND LIBFIM >AMV057

Sufficient Signal B-phase

PSV43 := PMV03 > 40 AND LICFIM >AMV056 OR PMV03 > 10 AND LICFIM >AMV057

Sufficient Signal C-phase

PSV44 := PMV01 > 40 AND PMV02 > 40AND PMV03 > 40 AND LIAFIM > AMV056AND LIBFIM > AMV056 AND LICFIM >AMV056

Sufficient Signal Three Phase –Part 1

PSV45 := PMV01 > 10 AND PMV02 > 10

AND PMV03 > 10 AND LIAFIM > AMV057AND LIBFIM > AMV057 AND LICFIM >AMV057

Sufficient Signal Three Phase –

Part 2

PSV46 := PSV44 OR PSV45 Sufficient Signal Three Phase

PMV41 := AMV041 * (PA_F * ASV041 +QA_F * NOT ASV041)

Phase A Power magnitude

PMV42 := AMV041 * (PB_F * ASV041 +QB_F * NOT ASV041)

Phase B Power magnitude

PMV43 := AMV041 * (PC_F * ASV041 +QC_F * NOT ASV041)

Phase C Power magnitude

PSV47 := (PMV41 > AMV054) AND PSV41 Phase A Power comparison

PSV48 := (PMV42 > AMV054) AND PSV42 Phase B Power comparison

PSV49 := (PMV43 > AMV054) AND PSV43 Phase C Power comparison

PMV44 := AMV044 * (3P_F * ASV042 +3Q_F * NOT ASV042)

Three Phase Power magnitude

PSV50 := (PMV44 > AMV055) AND PSV46 Three Phase Power comparison

PCT03PU := AMV043 PWRD

PCT03DO := 0.0

PCT03IN := PSV47 PWRA


PCT04DO := 0.0

PCT04IN := PSV48 PWRB


PCT05DO := 0.0

PCT05IN := PSV49 PWRC

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PCT06DO := 0.0

PCT06IN := PSV50 3PWR

a Free-form logic settings can include comments in order to facilitate good documentationpractices. Comments are preceded by the “#” character, e.g.,

PMV01 := VAFIM #VA magnitude.

Table 9: Automation 1 Free-Form Logic Settings (SET A 1 Command)

Automation Code #Comments

AMV001 := [user entered] 59 Phase Pickup (59PP)

AMV002 := [user entered] 59 3V0 Pickup (59NP)AMV003 := [user entered] 59 V2 Pickup (59QP)

AMV004 := [user entered] 59 V1 Pickup (59V1P)

AMV005 := [user entered] 27 Phase Pickup (27PP)



ASV021 := [user entered] Frequency Element Type: (1) forOverfrequency, (0) for Underfrequency

AMV021 := [user entered] Undervoltage Block Pickup (27B81P)

AMV022 := [user entered] Frequency Element Pickup (81DP)

AMV023 := [user entered] Frequency Element Time Delay (81DD)

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AMV041 := [user entered] Single Phase Direction Selection: (1.0)for (+), (–1.0) for (–)

ASV041 := [user entered] Single Phase Power Element Type: (1)for Watts, (0) for Vars (PWRT)

AMV042 := [user entered] Single Phase Power Element Pickup(PWRP)

AMV043 := [user entered] Single Phase Power Element TimeDelay (PWRD)

AMV044 := [user entered] Three Phase Direction Selection: (1.0)for (+), (–1.0) for (–)

ASV042 := [user entered] Three Phase Power Element Type: (1)for Watts, (0) for Vars (PWRT)

AMV045 := [user entered] Three Phase Power Element Pickup(3PWRP)

AMV046 := [user entered] Three Phase Power Element Time Delay(PWRD)



AMV051 := [user entered] Nominal Relay Current (INOM)

AMV052 := [user entered] Group Setting CTRW

AMV053 := [user entered] Group Setting PTRY

AMV054 := (AMV042 * AMV052 *AMV053) / 1E6

Single Phase Power Element Pickup(PWRP) converted to Primary units

AMV055 := (AMV045 * AMV052 *AMV053) / 1E6

Three Phase Power Element Pickup(3PWRP) converted to Primary units

AMV056 := 0.01 * AMV051 1% of Nominal Current

AMV057 := 0.1 * AMV051 10% of Nominal Current

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Table 13: SEL-351-7 Relay Word Bits and SEL-451 Equivalent

SEL-351-7 Relay

Word Bit

SEL-451 Relay

Word Bit Function

59A PSV01 A-phase Overvoltage

59B PSV02 B-phase Overvoltage

59C PSV03 C-phase Overvoltage

3P59 PSV04 3-phase Overvoltage

59N PSV05 3V0 Overvoltage

59Q PSV06 V2 Overvoltage

59V1 PSV07 V1 Overvoltage

27A PSV08 A-phase Undervoltage

27B PSV09 B-phase Undervoltage

27C PSV10 C-phase Undervoltage

3P27 PSV11 3-phase Undervoltage

27B81 PCT01Q Undervoltage Block

81DT PCT02Q Frequency

PWRA PCT03Q A-phase Power

PWRB PCT04Q B-phase Power

PWRC PCT05Q C-phase Power

3PWR PCT06Q 3-phase Power

Table 14: Protection SEL Variables

Variable Application Use

PSV01 59A

PSV02 59B

PSV03 59C

PSV04 3P59

PSV05 59N

PSV06 59Q

PSV07 59V1

PSV08 27A

PSV09 27B

PSV10 27C

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PSV11 3P27

PSV21 Frequency Element PhaseVoltage magnitude check

PSV22 81D

PSV41 Power Element Sufficient Signal A-phase

PSV42 Power Element Sufficient Signal B-phase

PSV43 Power Element Sufficient Signal C-phase

PSV44 Power Element Sufficient SignalThree Phase – Part 1

PSV45 Power Element Sufficient SignalThree Phase – Part 2

PSV46 Power Element Sufficient Signal Three Phase

PSV47 A-phase Power comparison

PSV48 B-phase Power comparison

PSV49 C-phase Power comparison

PSV50 3-phase Power comparison

Table 15: Automation SEL Variables


ASV021 Select Frequency Element

ASV041 Single phase PWRT

ASV042 Three phase PWRT

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Table 16: Protection Math Variables


PMV01 VAFIM

PMV02 VBFIM

PMV03 VCFIM

PMV04 3V0FIM

PMV05 3V2FIM / 3

PMV06 V1FIM

PMV21 FREQ

PMV41 A-phase Power (PA_f or QA_f)

PMV42 B-phase Power (PB_f or QB_f)

PMV43 C-phase Power (PC_f or QC_f)

PMV44 3-phase Power (3P_f or 3Q_f)

Table 17: Automation Math Variables


AMV001 59PP

AMV002 59NP

AMV003 59QP

AMV004 59V1P

AMV005 27PP

AMV021 27B81P

AMV022 81DP

AMV023 81DD

AMV041 Single-phase Power Direction Setting

AMV042 PWRP

AMV043 PWRD

AMV044 Three-phase Power Direction Setting

AMV045 3PWRP

AMV046 PWRD

AMV051 INOM

AMV052 CTRW

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AMV053 PTRY

AMV054 PWRP converted to Primary units

AMV055 3PWRP converted to Primary units

AMV056 1% of Nominal Current

AMV057 10% of Nominal Current

Table 18: Protection Conditioning Timers


PCT01Q Undervoltage Frequency Element block

PCT02Q Time-delayed Frequency Element

PCT03Q Time-delayed A-phase Power Element

PCT04Q Time-delayed B-phase Power Element

PCT05Q Time-delayed C-phase Power Element

PCT06Q Time-delayed Three-phase Power Element

FACTORY ASSISTANCE

We appreciate your interest in SEL products and services. If you have questions or comments,please contact us at:

Schweitzer Engineering Laboratories, Inc.2350 NE Hopkins CourtPullman, WA USA 99163-5603Telephone: (509) 332-1890Fax: (509) 332-7990Internet: www.selinc.com

All brand or product names appearing in this document are the trademark or registered trademark of their respective holders.

ACSELERATOR, Connectorized, CONSELTANT, Job Done, MIRRORED BITS, Schweitzer Engineering Laboratories, , SEL, SELOGIC, and SEL-PROFILE, areregistered trademarks of Schweitzer Engineering Laboratories, Inc.

Copyright © SEL 2004 (All rights reserved) Printed in USA.

ag_ag2004-12_20040823

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