Emerson Unidrive M101 - Page 49

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Unidrive M100 / M101 Control User Guide 49
Issue Number: 1
VM_MOTOR1_CURRENT_LIMIT Range applied to current limit parameters (motor 1)
Units %
Range of [MIN] 0.0
Range of [MAX] 0.0 to 1000.0
Definition
VM_MOTOR1_CURRENT_LIMIT[MAX] is dependent on the drive rating and motor set-up parameters.
VM_MOTOR1_CURRENT_LIMIT[MIN] = 0.0
Open-loop
VM_MOTOR1_CURRENT_LIMIT[MAX] = (I
Tlimit
/ I
Trated
) x 100 %
Where:
I
Tlimit
= I
MaxRef
x cos(sin
-1
(I
Mrated
/ I
MaxRef
))
I
Mrated
= Pr 05.007 sin φ
I
Trated
= Pr 05.007 x cos φ
cos φ = Pr 05.010
I
MaxRef
is 0.7 x Pr 11.061 when the motor rated current set in Pr 05.007 is less than or equal to Pr 11.032 (i.e. Heavy
duty).
Where:
Motor rated current is given by Pr 05.007
PF is motor rated power factor given by Pr 05.010
The Maximum current is (1.5 x Rated drive current) when the rated current set by Pr 05.007 is less than or equal to
the Maximum Heavy Duty current rating specified in Pr 11.032.
For example, with a motor of the same rating as the drive and a power factor of 0.85, the maximum current limit is
165.2%.
The rated active and rated magnetising currents are calculated from the power factor (Pr 05.010) and motor rated
current (Pr 05.007) as:
rated active current = power factor x motor rated current
rated magnetising current = √(1 - power factor
2
) x motor rated current
MOTOR1_CURRENT_LIMIT_MAX
Maximum current
Motor rated current
-------------------------------------------------------
2
PF()
2
1–+
PF
--------------------------------------------------------------------------------------------------------
100%×=
VM_NEGATIVE_REF_CLAMP1 Limits applied to the negative frequency clamp (motor 1)
Units Hz
Range of [MIN] -550.00 to 0.00
Range of [MAX] 0.00 to 550.00
Definition
This variable maximum/minimum defines the range of the negative frequency clamp associated with motor map 1
(Minimum Reference Clamp (01.007)). The minimum and maximum are affected by the settings of the Negative
Reference Clamp Enable (01.008), Bipolar Reference Enable (01.010) and Maximum Reference Clamp (01.006) as
shown in the table below.
Negative
Reference Clamp
Enable (01.008)
Bipolar
Reference
Enable (01.010)
VM_NEGATIVE_REF_
CLAMP1[MIN]
VM_NEGATIVE_REF_
CLAMP1[MAX]
00 0.00 Pr 01.006
0 1 0.00 0.00
1X
-
VM_POSITIVE_REF_CLAMP[MAX]
0.00
VM_POSITIVE_REF_CLAMP Limits applied to the positive frequency reference clamp
Units Hz
Range of [MIN] 0.00
Range of [MAX] 550.00
Definition
VM_POSITIVE_REF_CLAMP[MAX] defines the range of the positive reference clamp, Maximum Reference Clamp
(01.006), which in turn limit the references.