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