GE UR Series Instruction Manual Page 129

Line differential relay.

5 SETTINGS
VIRTUAL OUTPUT 1
State=ON
VIRTUAL OUTPUT 2
State=ON
VIRTUAL INPUT 1
State=ON
DIGITAL ELEMENT 1
State=Pickup
VIRTUAL OUTPUT 3
State=ON
CONTACT INPUT H1c
State=Closed
4.
Program the FlexLogic™ equation for Virtual Output 3 by translating the logic into available FlexLogic™ parameters.
The equation is formed one parameter at a time until the required logic is complete. It is generally easier to start at the
output end of the equation and work back towards the input, as shown in the following steps. It is also recommended to
list operator inputs from bottom to top. For demonstration, the final output will be arbitrarily identified as parameter 99,
and each preceding parameter decremented by one in turn. Until accustomed to using FlexLogic™, it is suggested that
a worksheet with a series of cells marked with the arbitrary parameter numbers be prepared, as shown below.
5.
99: The final output of the equation is Virtual Output 3, which is created by the operator "= Virt Op n". This parameter
is therefore "= Virt Op 3."
98: The gate preceding the output is an AND, which in this case requires two inputs. The operator for this gate is a 2-
input AND so the parameter is "AND(2)". Note that FlexLogic™ rules require that the number of inputs to most
types of operators must be specified to identify the operands for the gate. As the 2-input AND will operate on the
two operands preceding it, these inputs must be specified, starting with the lower.
97: This lower input to the AND gate must be passed through an inverter (the NOT operator) so the next parameter is
"NOT". The NOT operator acts upon the operand immediately preceding it, so specify the inverter input next.
96: The input to the NOT gate is to be contact input H1c. The ON state of a contact input can be programmed to be
set when the contact is either open or closed. Assume for this example the state is to be ON for a closed contact.
The operand is therefore "Cont Ip H1c On".
95: The last step in the procedure is to specify the upper input to the AND gate, the operated state of digital element
2. This operand is "DIG ELEM 2 OP".
Writing the parameters in numerical order can now form the equation for VIRTUAL OUTPUT 3:
GE Power Management
Set
LATCH
OR #1
Reset
XOR
Timer 1
Time Delay
on Pickup
(800 ms)
Figure 5–11: LOGIC FOR VIRTUAL OUTPUT 4
01
02
03
04
05
97
98
99
Figure 5–12: FLEXLOGIC™ WORKSHEET
L90 Line Differential Relay
Timer 2
Time Delay
OR #2
on Dropout
(200 ms)
827029A1.VSD
5.4 FLEXLOGIC™
VIRTUAL
OUTPUT 4
827028A2.VSD
5
5-45

L90