MX2 Quick Start Guide
22 MX2 Quick Start Guide
DC braking at startup is also possible by independent setup of parameters A057 and A058. This is useful in aplications were load
should be totally stopped before starting the movement.
Be careful to avoid specifying to long braking time or to hihg carrier frequency that can cause motor overheating. If you use DC
braking is recommended to use motors with a built-in thermistor and wire it to inverter’s thermistor input.
3.9 V/F Curve
The inverter generates the motor output according to the V/f algorithm selected on parameter A044. The factory default is Con-
stant torque (“00”). Review the following description to help you choose the best torque control algorithm for your application.
Review following description to help you choose the best torque control algo-
rithm for your application:.
• Constant and Variable (Reduced) Torque - The graph at right shows the
constant torque characteristic from 0 Hz to the base frequency A003. The
voltage remains constant for output frequencies higher than the base fre-
quency.
• Variable torqu e - The graph at right shows the variable (reduced) torque
curve, which has a constant torque characteristic from 0 Hz to 10% of the
base frequency. This helps to achieve higher torque at low speed with
reduced torque curve at higher speeds.
• Sensorless Vector Control - You can achieve high torque performance
(200% torque at 0.5 Hz of output frequency) without motor speed feedback
but a god tuning of the motor is necessary to do it. Please remember to per-
form auto-tuning for this control method. (A044=”3”)
• Free V/F Control - The free V/F setting function allows you to set an arbi-
trary V/F characteristics by specifying the voltages and frequencies
(b100~b113) for seven points on the V/F characteristic curve (A044=”2”)
Parameter Parameter Name Description
A051 DC braking enable Three options; select codes:
00... Disable
01... Enable during stop
02... Frequency detection
A052 DC braking frequency The frequency at which DC braking begins, range is from the start
frequency (B082) to 60Hz
A053 DC braking wait time The delay from the end of controlled deceleration to start of DC
braking (motor free runs until DC braking begins), range is 0.0 to
5.0 sec.
A054 DC braking force for
deceleration
Level of DC braking force, settable from 0 to 100%
A055 DC braking time for deceleration Sets the duration for DC braking, range is from 0.0 to 60.0 seconds
A056 DC braking / edge or level
detection for [DB] input
Two options; select codes:
00... Edge detection
01... Level detection
A057 DC braking force at start Level of DC braking force at start, settable from 0 to 100%
A058 DC braking time at start Sets the duration for DC braking, range is from 0.0 to 60.0 seconds
A059 Carrier frequency during
DC braking
Carrier frequency of DC braking performance, range is from 2.0
to 15.0 kHz
Hz
100%
0
V
A044 = 00
Constant torque
A044
=
01
Hz
100%
0
V Variable torque
Max.
freq.
Base
freq.
Max.
freq.
Base
freq.
10% Base
freq.
I129E-EN-02+MX2+QuickStartGuide.book Seite 22 Mittwoch, 7. November 2012 1:54 13
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