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b2-04: DC Injection Braking Time at Stop
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.
Name
Setting Range
Default
b2-04
DC Injection Braking Time at Stop
0.00 to 10.00 s
0.50 s
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b2-08: Magnetic Flux Compensation Value
Sets the magnetic flux compensation as a percentage of the no-load current value (E2-03) and can be used to increase the
motor flux when the motor is started up.
No.
Name
Setting Range
Default
b2-08
Magnetic Flux Compensation Value
0 to 1000%
0%
This parameter allows the magnetizing motor flux to be boosted when starting the motor and thereby facilitate a quick
ramp-up of the torque reference and magnetizing current reference in order to reduce motor slip during start. This flux
level will be applied below the minimum output frequency set to E1-09 until the DC Injection time at start (b2-03) expires.
It may be used to compensate for reduced starting torque due to motor circuit inefficiencies.
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b2-12: Short Circuit Brake Time at Start
Short-Circuit braking can be used in Open Loop Vector for PM motors. By shorting all three motor phases it produces a
braking torque in the motor and can be used to stop a coasting motor before starting it.
Parameter b2-12 sets the time for Short-Circuit Brake operation at start. Disabled when set to 0.00 s.
No.
Name
Setting Range
Default
b2-12
Short Circuit Brake Time at Start
0.00 to 25.50 s
0.00 s
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b2-13: Short Circuit Brake Time at Stop
The Short-Circuit braking described for parameter b2-12 can also be applied at the end of deceleration in order to completely
stop high inertia loads. Short circuit braking is initiated when the output frequency falls below the higher of the values
b2-01 and E1-09.
Parameter b2-13 sets the time for Short-Circuit brake operation at stop. Disabled when set to 0.00 s.
No.
Name
Setting Range
Default
b2-13
Short Circuit Brake Time at Stop
0.00 to 25.50 s
0.50 s
u
b3: Speed Search
The Speed Search function allows the drive to detect the speed of a rotating motor shaft that is driven by external forces
(e.g. fan rotating by windmill effect or motor driven by load inertia). The motor operation can be directly started from the
speed detected without needing to stop the machine before.
Example: When a momentary loss of power occurs, the drive output shuts off. This results in a coasting motor. When
power returns, the drive can find the speed of the coasting motor and restart it directly.
The drive offers two types of Speed Search, Speed Estimation and Current Detection. Both methods are explained below
followed by a description of all relevant parameters.
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Speed Estimation Type Speed Search (b3-24 = 1)
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.
5.2 b: Application
110
SIEP C710606 20 OYMC AC Drive - V1000 User Manual
7/16/2008-13:23
