BENSHAW RSi H2 Series - Detecting the Initial Pole Position; Speed Search Operation for PM Motor

Sensorless Vector Control
251
890053-00-02
7.2.3 Detecting the Initial Pole Position
Initial pole position detection is a process to match the rotor position calculated by the inverter and
the actual rotor position in a motor. In a permanent-magnet (PM) synchronous motor, rotor flux is
generated from the permanent magnet attached to the rotor. Therefore, to run the motor in vector
control mode, the exact rotor position (flux position) must be detected for accurate control of the
torque generated by the motor.
Code
Keypad
Display
Description
Setting Value
Setting
Range
Units
BAS-94
Init Angle Sel
Initial pole position estimation type
0: None
0~2
-
1: Angle
Detect
2: Alignment
BAS-95
PD Repeat
Num
Pole position estimation retry count
2
0~10
-
BAS-96
Pulse Interval
Pole position detection interval
20
1~100msec
msec
BAS-97
Pulse Curr %
Pole position detection pulse current
(%)
25
10~100%
%
BAS-98
Pulse Volt %
Pole position detection pulse
voltage %
500
100~4000
-
Pole Position Setting Details
Code
Description
BAS-94 Init Angle Sel
Select the type of initial pole position detection.
When BAS-94 is set to 0 (None), the motor is operated according to the pole
position estimated by the inverter’s sensorless control algorithm, instead of
actually detecting the physical position of the rotor pole.
When BAS-94 is set to 1 (Angle Detect), the motor is operated according to the
pole position detected by changes in the current. The voltage pulse input is
used to detect the pole position and results in a small amount of noise at motor
startup.
When BAS-94 is set to 2 (Alignment), the inverter forcefully align the rotor
position by supplying DC current for a certain period of time.
7.2.4 CON-69 Speed Search Operation for PM motor
This operation is used to prevent faults that can occur when the inverter starts a motor that is
idling. Because this feature estimates the motor rotation speed based on the inverter output
current, it does not give the exact speed.
Code
Keypad Display
Description
Setting Value
Setting Range
Units
CON-69
SS Pulse Curr
PM speed search
pulse current
15%
10~100
%
CON-70
SS Mode
Speed search mode
2: Flying Start-3
2
Flying Start-3
-
CON-71
Speed Search
Speed Search operation
selection
0000
0000-1111
bit
CON-75
SS Block Time
Output block time before
speed search
1.0sec
0~60.0
sec