Digitax ST User Guide
113
Issue Number: 5
Parameter ranges and variable maximums:
The two values provided define the minimum and maximum values for the given parameter. In some cases the parameter range is variable and
dependant on either:
•
other parameters
•
the drive rating
•
drive mode
•
or a combination of these
The values given in Table 12-4 are the variable maximums used in the drive.
Table 12-4 Definition of parameter ranges & variable maximums
Maximum
Definition
SPEED_REF_MAX
[40000.0rpm]
Maximum speed reference
If Pr
1.08
= 0: SPEED_REF_MAX = Pr
1.06
If Pr
1.08
= 1: SPEED_REF_MAX is Pr
1.06
or – Pr
1.07
whichever is the largest
(If the second motor map is selected Pr
21.01
is used instead of Pr
1.06
and Pr
21.02
instead of Pr
1.07
)
SPEED_LIMIT_MAX
[40000.0rpm]
Maximum applied to speed reference limits
A maximum limit may be applied to the speed reference to prevent the nominal encoder frequency from
exceeding 500 kHz. The maximum is defined by
SPEED_LIMIT_MAX (in rpm) = 500 kHz x 60 / ELPR = 3.0 x 10
7
/ ELPR subject to an absolute maximum of
40,000 rpm.
ELPR is equivalent encoder lines per revolution and is the number of lines that would be produced by a
quadrature encoder.
Quadrature encoder ELPR = number of lines per revolution
F and D encoder ELPR = number of lines per revolution / 2
Resolver ELPR = resolution / 4
SINCOS encoder ELPR = number of sine waves per revolution
Serial comms encoder ELPR = resolution / 4
This maximum is defined by the device selected with the speed feedback selector (Pr
3.26
) and the ELPR set
for the position feedback device.
SPEED_MAX
[40000.0rpm]
Maximum speed
This maximum is used for some speed related parameters in menu 3. To allow headroom for overshoot etc. the
maximum speed is twice the maximum speed reference.
SPEED_MAX = 2 x SPEED_REF_MAX
DRIVE_CURRENT_MAX
[9999.99A]
Maximum drive current
The maximum drive current is the current at the over current trip level and is given by:
DRIVE_CURRENT_MAX = K
C
/ 0.45
AC_VOLTAGE_SET_MAX
[690V]
Maximum output voltage set-point
Defines the maximum motor voltage that can be selected.
200 V drives: 240 V, 400 V drives: 480 V
AC_VOLTAGE_MAX
[930V]
Maximum AC output voltage
This maximum has been chosen to allow for maximum AC voltage that can be produced by the drive including
quasi-square wave operation as follows:
AC_VOLTAGE_MAX = 0.78 x DC_VOLTAGE_MAX
200 V drives: 325 V, 400 V drives: 650 V
DC_VOLTAGE_SET_MAX
[1150V]
Maximum DC voltage set-point
200 V rating drive: 0 to 400 V, 400 V rating drive: 0 to 800 V
DC_VOLTAGE_MAX
[1190V]
Maximum DC bus voltage
The maximum measurable DC bus voltage.
200 V drives: 415 V, 400 V drives: 830 V
MOTOR1_CURRENT_LIMIT_MAX
[1000.0%]
Where:
The Maximum current is either (1.75 x K
C
) when the motor rated current set in Pr
5.07
is less than or equal to the
maximum Heavy Duty current rating given by Pr
11.32
, otherwise it is (1.1 x Normal Duty rating).
Motor rated current is given by Pr
5.07
MOTOR2_CURRENT_LIMIT_MAX
[1000.0%]
Maximum current limit settings for motor map 2
This maximum current limit setting is the maximum applied to the current limit parameters in motor map 2.
The formulae for MOTOR2_CURRENT_LIMIT_MAX are the same for MOTOR1_CURRENT_LIMIT_MAX
except that Pr
5.07
is replaced with Pr
21.07
and Pr
5.10
is replaced with Pr
21.10
.
TORQUE_PROD_CURRENT_MAX
[1000.0%]
Maximum torque producing current
This is used as a maximum for torque and torque producing current parameters. It is
MOTOR1_CURRENT_LIMIT_MAX or MOTOR2_CURRENT_LIMIT_MAX depending on which motor map is
currently active.
Maximum
current limit
=
[
Maximum current
]
x 100%
Motor rated current
Summary of Contents for Digitax ST
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