Mitsubishi Electric 800 Series Instruction Manual page 171

Speed control under Real sensorless vector control, vector control, PM sensorless vector
control
P/PI control switchover according to the motor speed (Pr.1348)
• When the motor speed falls below the Pr.1348 setting during speed control under Real sensorless vector control or Vector
control, speed loop integration is stopped and the accumulated integral term is cleared.
Pr.1348 setting or more: PI control
Less than the Pr.1348 setting: P control
• The shock of P/PI control switchover is absorbed by setting Pr.1115 Speed control integral term clear time. When the
motor speed falls below the Pr.1348 setting, speed loop integration is stopped and the accumulated integral term is
reduced and cleared according to the Pr.1115 setting (initial value is 0 ms). In Pr.1115, set time when the integral term is
reduced from 100% to 0% regarding the rated torque current (Iq) as 100%. When the motor speed is increased to the
Pr.1348 setting plus 2 Hz or more, integral operation is resumed.
NOTE
• The speed loop integration can be disabled at the emergency stop using Pr.1349 Emergency stop operation selection.
page 269
(Refer to
170
PARAMETERS
.)