Xenus Plus User Guide
16-01344 Rev 06
Copley Controls
140
B.1: I
2
T Algorithm
B.1.1: I
2
T Overview
The I
2
T current limit algorithm continuously monitors the energy being delivered to the motor using
the I
2
T Accumulator Variable. The value stored in the I
2
T Accumulator Variable is compared with the
I
2
T setpoint that is calculated from the user-entered Peak Current Limit, I
2
T Time Limit, and
Continuous Current Limit. Whenever the energy delivered to the motor exceeds the I
2
T setpoint, the
algorithm protects the motor by limiting the output current or generates a fault.
B.1.2: I
2
T Formulas and Algorithm Operation
Calculating the I
2
T Setpoint Value
The I
2
T setpoint value has units of Amperes
2
-seconds (A
2
S) and is calculated from programmed
motor data. The setpoint is calculated from the Peak Current Limit, the I
2
T Time Limit, and the
Continuous Current Limit as follows:
I
2
T setpoint =
(Peak Current Limit
2
– Continuous Current Limit
2
) * I
2
T Time Limit
I
2
T Algorithm Operation
During drive operation, the I
2
T algorithm periodically updates the I
2
T Accumulator Variable at a rate
related to the output current Sampling Frequency. The value of the I
2
T Accumulator Variable is
incrementally increased for output currents greater than the Continuous Current Limit and is
incrementally decreased for output currents less than the Continuous Current Limit. The I
2
T
Accumulator Variable is not allowed to have a value less than zero and is initialized to zero upon
reset or +24 Vdc logic supply power-cycle.
Accumulator Increment Formula
At each update, a new value for the I
2
T Accumulator Variable is calculated as follows:
I
2
T Accumulator Variable n+1 =
I
2
T Accumulator Variable n
+(Actual Output Current n+1
2
– Continuous Current Limit
2
) * Update period
After each sample, the updated value of the I
2
T Accumulator Variable is compared with the I
2
T
setpoint. If the I
2
T Accumulator Variable value is greater than the I
2
T Setpoint value, then the drive
limits the output current to the Continuous Current Limit. When current limiting is active, the output
current will be equal to the Continuous Current Limit if the commanded current is greater than the
Continuous Current Limit. If instead the commanded current is less than or equal to the Continuous
Current Limit, the output current will be equal to the commanded current.
Содержание XEL-230-18
Страница 1: ...123123 P N 16 01344 Revision 06 August 30 2019 Xenus Plus User Guide...
Страница 2: ...Xenus Plus User Guide 16 01344 Rev 06 This page for notes...
Страница 9: ...Xenus Plus User Guide 16 01344 Rev 06 Copley Controls 9 This page for notes...
Страница 18: ...Xenus Plus User Guide 16 01344 Rev 06 Copley Controls 18...
Страница 82: ...Xenus Plus User Guide 16 01344 Rev 06 Copley Controls 82 3 25 3 XE2 XP2 XM2 non N models 800 1819 Dimensions...
Страница 116: ...Xenus Plus User Guide 16 01344 Rev 06 Copley Controls 116 Optically Isolated Programmable Outputs Wiring Diagram...
Страница 120: ...Xenus Plus User Guide 16 01344 Rev 06 Copley Controls 120 Analog Input Wiring Diagram Multi Mode Port Interface Diagram...
