P.14.31
Date Code 20151029 Protection Manual SEL-411L Relay
SELOGIC Control Equation Programming
SEL
OGIC Control Equation Operators
AMV002 := SQRT (AMV005 + AMV034) # Calculates the square root of the
sum
AMV003 := SQRT (AMV007) # Produces a math error if AMV007 is negative
LN, EXP, and LOG
LN and EXP are complementary functions for operating with natural
logarithms or logarithms calculated to the natural base e. LN calculates the
natural logarithm of the argument. LOG calculates the base 10 logarithm of
the argument. A negative or zero argument for the LN and LOG operation
results in a math error and assertion of the corresponding math error bit
described in Arithmetic. EXP calculates the value of e raised to the power of
the argument. Example 14.16 shows examples of expressions that use the LN,
EXP, and LOG operators. Use parentheses to delimit the argument of a LN,
EXP, or LOG operation.
EXAMPLE 14.16 Using the LN, EXP, and LOG Operators
The free-form math SEL
OGIC control equations below are examples of
LN, EXP, and LOG operator usage.
# LN examples
AMV001 := LN (AMV009) # Natural logarithm of AMV009
AMV002 := LN (AMV009 + AMV034) # Natural logarithm of the sum
AMV003 := LN (AMV010) # Produces error if AMV010 is 0 or negative
# EXP examples
AMV004 := EXP (2) # Calculates e squared
AMV005 := EXP (AMV003) # Calculates e to the power AMV003
AMV006 := EXP (AMV046 + AMV047) # e raised to the power of the sum
# LOG examples
AMV007 := LOG (AMV012) # Base 10 logarithm of AMV012
AMV008 := LOG (AMV012 + AMV022) # Base 10 logarithm of the sum
AMV009 := LOG (AMV100) # Produces an error if AMV100 is 0 or negative
SIN and COS
Use the SIN or COS operators to calculate the sine or cosine of the argument.
SIN and COS operate in degrees, the unit of angular measure the relay uses to
express metering quantities. Example 14.17 shows examples of SIN and COS.
Use parentheses to delimit the argument of a SIN or COS operation.
EXAMPLE 14.17 Using the SIN and COS Operators
The free-form math SEL
OGIC control equations below are examples of
SIN and COS.
# SIN examples
AMV001 := SIN (AMV005) # Sine of AMV005
AMV002 := SIN (AMV005 + AMV034) # Sine of the sum
# COS examples
AMV003 := COS (AMV005) # Cosine of AMV005
AMV004 := COS (AMV005 + AMV006) # Cosine of the sum
ASIN and ACOS
Use the ASIN or ACOS operators to calculate the angle resulting from the
trigonometric function equivalent to a given number (the argument), where the
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