YASKAWA iQpump Micro CIMR-PW Series User Manual page 124

5.2 b: Application
b2-02: DC Injection Braking Current
n
Sets the DC Injection Braking current as a percentage of the drive rated current. If set to larger than 50%, the carrier frequency
is automatically reduced to 1 kHz.
No.
b2-02
The level of DC Injection Braking current affects the strength of the magnetic field attempting to lock the motor shaft.
Increasing the current level will increase the amount of heat generated by the motor windings. This parameter should only be
increased to the level necessary to hold the motor shaft.
b2-03: DC Injection Braking Time at Start
n
Sets the time of DC Injection Braking at start. It can be used to stop a coasting motor before restarting it or to apply a braking
torque at start. Disabled when set to 0.00 s.
No.
b2-03
b2-04: DC Injection Braking Time at Stop
n
This parameter works in combination with b2-01, and sets the DC Injection Braking time at stop. Used to completely stop a
motor with high inertia load after ramp down. Increase the setting if the motor tends to coast by inertia after a stop.
No.
b2-04
Speed Estimation Type Speed Search (b3-24 = 1)
n
This method can be used for a single motor connected to a drive. It should not be utilized if the motor is one or more frame
sizes smaller than the drive, at motor speeds above 130 Hz, or when using a single drive to operate more than one motor.
The Speed Estimation type distinguishes two kinds of operation, Back EMF voltage estimation and DC current injection.
Back EMF Voltage Estimation
This method is used by Speed Search after short Baseblock (e.g. a power loss where the drives CPU kept running and the Run
command was kept active). Here the drive estimates the motor speed by analyzing the back EMF voltage. It outputs the
estimated frequency and increases the voltage using the time constant set in parameter L2-04. After that the motor is accelerated
or decelerated to the frequency reference starting from the detected speed.
124
output
frequency
Figure 5.12 DC Injection Braking during Deceleration
Name
DC Injection Braking Current
Name
DC Injection Braking Time at Start
Name
DC Injection Braking Time at Stop
AC power
supply
ON
Output
frequency
Output
current
Min. Baseblock Time
(L2-03)
Figure 5.13 Speed Search after Baseblock
b2-01
braking time
b2-04
OFF
Starts at the detected speed
Several milliseconds
b3 -05 <1>
YASKAWA TOEP YAIQPM 03B YASKAWA AC Drive - iQpump Micro User Manual
DC Injection Braking
start frequency
Setting Range
0 to 75%
Setting Range
0.00 to 10.00 s
Setting Range
0.00 to 10.00 s
Selected
frequency
reference
Default
50%
Default
0.50 s
Default
0.50 s