Mitsubishi Electric FR-A700 Instruction Manual page 280

Speed control by real sensorless vector control, vector control
Speed feed forward control (Pr. 877 = 1)
● Calculate required torque in responce to the acceleration/deceleration command for the
inertia ratio set in Pr. 880 and generate torque immediately.
● When the speed feed forward gain is 100%, the calculation result of the speed feed forward
is reflected as-is.
● If the speed command changes suddenly, large torque is generated due to the speed feed
forward calculation. The maximum value of the speed feed forward is limited using Pr. 879.
● Using Pr. 878, the speed feed forward result can be dulled by the primary delay filter.
Model adaptive speed control (Pr. 877 = 2)
● The motor's model speed is calculated to feed back the model side speed controller. This
model speed is also used as the actual speed controller command.
● The inertia ratio in Pr. 880 is used for calculation of the torque current command value given
by the model side speed controller.
● The torque current command value of the model side speed controller is added to the output
of the actual speed controller, and the result is used as the iq current control input.
Pr. 828 is used for model side speed control (P control), and the first gain in Pr. 820 is used
for the actual speed controller. The model adaptive speed control is valid for the first motor
only.
● When Pr. 877 = 2, switching to the second motor handles the second motor as Pr. 877 = 0.
NOTE The adequate gain value for the model and actual loop parts are set according to the
responce setting of easy gain tuning under model adaptive speed control. To increase the
responce level, the Pr. 818 "Easy gain tuning response level setting" needs to be changed
(increased).
6 - 100
Parameter