Mitsubishi Electric 800 Series Instruction Manual page 433

(C) Motor constant parameters
Changing the motor constants
• If the motor constants are known, the motor constants can be set directly or set using data measured through offline auto
tuning.
• According to the Pr.71 (Pr.450) setting, the range of the motor constant parameter setting values and units can be
changed. The setting values are stored in the EEPROM as motor constant parameters, and three types of motor constants
can be stored.
Changing the motor constants (If setting the Pr.92 and Pr.93 motor
constants in units of mH)
• Set Pr.71 as shown below.
Motor
Standard motor
Constant-torque motor
Vector control dedicated motor
• Use the following formula to find the Pr.94 setting value and set a given value as the motor constant parameter.
The setting value of Pr.94 = (1 -
R1 I1
V M
L1= I1+ M: Primary inductance
L2= I2+ M: Secondary inductance
Equivalent circuit diagram of the motor
First Second
motor Pr. motor Pr.
Motor excitation current
82 455
(No-load current)
90 458 Motor constant (R1)
91 459 Motor constant (R2)
Motor constant (L1)/d-axis
92 460
inductance (Ld)
Motor constant (L2)/q-axis
93 461
inductance (Lq)
94 462 Motor constant (X)
Torque current/Rated PM motor
859 860
current
298 560 Frequency search gain

For the FR-A860-01080 or lower.

For the FR-A860-01440 or higher.
NOTE
• "If "9999" is set, tuning data will be invalid and the motor constant values for standard motors / vector control dedicated
motors are used.
432
PARAMETERS
Pr.71 setting
0 (initial value)
1
30
2
M
L1  L2
I2
R1: Primary resistance
R2: Secondary resistance
I1: Primary leakage inductance
R2/S
I2: Secondary leakage inductance
M: Excitation inductance
S: Slip
Name
)  100(%)
Setting range
0 to 500 A, 9999

0 to 3600 A, 9999

0 to 50 Ω, 9999

0 to 400 mΩ, 9999

0 to 50 Ω, 9999

0 to 400 mΩ, 9999

0 to 6000 mH, 9999

0 to 400 mH, 9999

0 to 6000 mH, 9999

0 to 400 mH, 9999

0 to 100%, 9999
0 to 500 A, 9999

0 to 3600 A, 9999

0 to 32767, 9999
Setting Initial
increments value
0.01 A

0.1 A

0.001 Ω

0.01 mΩ

0.001 Ω

0.01 mΩ

0.1 mH

0.01 mH 9999

0.1 mH

0.01 mH

0.1%

0.01%

0.01 A

0.1 A

1