Download Stellaris LM3S818 AC Induction Motor

Parameter Descriptions
be used. Sine wave modulation is the only accepted modulation type when a single-phase motor
is being driven.
Sine wave modulation is easy to understand but only provides 86.6% utilization of the DC bus.
Space vector modulation is more complicated but provides 100% utilization of the DC bus. Better
utilization of the DC bus results in more output torque from the motor.
The value of this parameter can not be changed while the motor drive is running.
Motor Drive Direction
ID
PARAM_DIRECTION
Units
Range
Default
Boolean
0 to 1
0
This parameter specifies the direction of rotation for the motor drive. Since the motor drive has no
knowledge of the connection of the windings to the drive, it can not be said that one particular
value means clockwise rotation and the other means counter-clockwise rotation. Changing the
value of this parameter reverses the direction of rotation.
The value of this parameter can only be changed for three-phase motors; this parameter is forced
to 0 for single-phase motors.
Acceleration Rate
ID
PARAM_ACCEL
Units
Range
Default
Hertz/second
1 to 100
40
This parameter is the rate at which the output frequency increases when it is less than the target
frequency. When in Closed-Loop mode, this is the maximum rate of acceleration that is allowed,
though lower acceleration rates can be utilized.
The rate of acceleration can also be viewed as the rate that slip is introduced into the motor drive.
Slip causes an increase in the current through the motor, so setting the acceleration too high may
result in the over-current fault tripping due to excessive slip.
Deceleration Rate
ID
PARAM_DECEL
Units
Range
Default
Hertz/second
1 to 100
40
This parameter is the rate at which the output frequency decreases when it is greater than the
target frequency. If the DC bus voltage exceeds the value of the DC Bus Deceleration Voltage
parameter, the value of this parameter will be temporarily scaled back to slow the rise in the DC
bus voltage. If the DC bus voltage is below the DC Bus Deceleration Voltage parameter and this
parameter was previously scaled back, it will be slewed back to the parameter value at a rate of ¼
Hz/sec every millisecond. When in Closed-Loop mode, this is the maximum rate of deceleration
that is allowed, though lower deceleration rates can be utilized.
Setting this parameter value too high may result in DC bus voltage increases that can not be
handled by deceleration rate scaling and dynamic braking. In this case, a DC bus over-voltage
fault will occur.
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November 4, 2009