# Mitsubishi Electric FR-A820-00046 (0.4K) Instruction Manual Page 250

Fr-a800 series.

 Compensating the speed control P gain in the constant output range
(Pr.1116)
• In the constant output range (rated speed or higher), the response of speed control is reduced due to weak field. Thus, the
speed control P gain is needed to be compensated using Pr.1116 Constant output range speed control P gain
compensation.
• In Pr.1116, set a compensation amount for the doubled rated speed regarding the speed control P gain at the rated speed
or lower as 100%.
(Speed control P gain at rated speed or higher) = (Speed control P gain at rated speed or lower) × (100% + compensation
amount)
Compensation amount = Pr.1116/Rated speed × (Speed - Rated speed)
 Setting the speed control P gain in the per-unit system (Pr.1117, Pr.1118,
Pr.1121)
• The speed control P gain can be set in the per-unit (pu) system.
• In the per-unit system:
When "1" is set, the torque (Iq) command is 100% (rated Iq) when the speed deviation is 100%.
When "10" is set, the torque (Iq) command is 10% (rated Iq) when the speed deviation is 100%.
Set the 100% speed in Pr.1121 Per-unit speed control reference frequency.
• The speed control P gain becomes as follows according to Pr.1117 Speed control P gain 1 (per-unit system), Pr.1118
Speed control P gain 2 (per-unit system), and the RT signal.
Pr.1117
Pr.1118
Pr.830
9999
9999
9999
Other than
9999
Other than
9999
9999
Other than
9999
9999
Other than
Other than
9999
9999
NOTE
• The per-unit system setting is available only under Real sensorless vector control or Vector control.
• When the speed control P gain or model speed control gain is set in the per-unit system, the easy gain tuning selection
(Pr.819="1 or 2") becomes invalid.
 Switching over P/PI control (Pr.1115, X44 signal)
• In speed control under Real sensorless vector control or Vector control, whether or not to add the integral time (I) when
performing gain adjustment with P gain and integral time can be performed with the P/PI control switchover signal (X44).
When X44 signal is OFF...PI control
When X44 signal is ON...P control
Ratio multiplied to
speed control P gain
200%
150%
100%
0%
Rated speed
RT signal
Speed control P gain
OFF
Pr.820
ON
Pr.820
ON
Pr.830
Pr.1117
OFF
Pr.820
ON
Pr.1118
OFF
Pr.1117
ON
Pr.1118
5.3 Speed control under Real sensorless vector control, vector control, PM sensorless vector control
Pr.1116=100%
Pr.1116=50%
Pr.1116=0%(Initial value)
Speed
Rated speed×2
1
2
3
4
5
6
7
8
9
10
249
5. PARAMETERS  