Outline Of Pm Sensorless Vector Control; Automatic Parameter Setting In Accordance With The Motor (Pr.998) - Mitsubishi Electric FR-E700EX Instruction Manual

4.3 PM sensorless vector control
4.3.1

Outline of PM sensorless vector control

A dedicated PM (magnet) motor is a highly efficient motor compared to an induction motor. With this PM motor, highly efficient
motor control and highly accurate motor speed control can be performed.
Without using a speed detector such as an encoder, the motor speed is detected based on the output voltage and current of
the drive unit, and highly accurate speed control and position control can be performed.
Speed
command
POINT
 The following conditions must be met to perform PM sensorless vector control.
 For the motor model, dedicated PM motor must be used.
 A specified combination of the motor capacity and the drive unit capacity must be used.
 Single-motor operation (one motor run by one drive unit) must be performed.
 The overall wiring length with the motor must be 30m or less.
NOTE
 In the low-speed range (about 100 r/min or lower), rotation ripple occurs due to cogging torque of the motor.
 The RUN signal is output about 100 ms after turning ON the start command (STF, STR). The delay is due to the
magnetic pole detection.
4.3.2

Automatic parameter setting in accordance with the motor (Pr.998)

 Performing PM parameter initialization automatically adjusts the parameter initial settings and setting ranges required to drive the
PM motor being used.
 Initialization is performed by setting Pr.998 PM parameter initialization or by choosing the mode on the operation panel.
Parameter
Name
number
PM parameter
998
initialization
The above parameters can be set when Pr.160 Extended function display selection = "0". (Refer to page 182)

The setting differs according to the drive unit capacity. (0.75K or lower / 1.5K or higher)

The setting is available only with the 0.1K to 0.75K class.

The setting is available only with the 0.2K to 3.7K class.
.......Specifications differ according to the date assembled. Refer to page 316 to check the SERIAL number.
(1) PM parameter initialization (Pr.998)
 When Pr.998 ="3024 or 6004", the monitor is displayed and the speed is set using the motor rotations per minute.
To use frequency to display or set, set Pr.998 ="3124 or 6104".
Pr.998 setting
3024 Parameter settings for an MM-GKR motor (rotations per minute)
3124 Parameter settings for an MM-GKR motor (frequency)
6004 Parameter settings for an S-PM geared motor (rotations per minute)
6104 Parameter settings for an S-PM geared motor (frequency)
PM sensorless vector control image
Drive unit Output
voltage
Controller
Magnetic field observer
Speed/magnetic
pole position Virtual motor
Initial Setting
value range
3024 Parameter settings for an MM-GKR motor (rotations per minute)

3124  Parameter settings for an MM-GKR motor (frequency)
3024/
6004 
6004  Parameter settings for an S-PM geared motor (rotations per minute)
6104 Parameter settings for an S-PM geared motor (frequency)

Description
PM sensorless vector control
Inverter
circuit
∗
Output  A magnetic field observer is a control
current
method that calculates the motor speed/
magnetic pole position based on the
motor voltage and current of a virtual
motor which is set up in the drive unit.
Operation
Operation after selecting the parameter
setting mode on the operation panel
(PM)  write "3024"
Not available
(PM)  write "6004"
Not available
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