5.2 Control method V/F control (initial setting) and General-purpose magnetic flux vector control are available with this inverter. V/F control The inverter controls the output frequency (F) and the output voltage (V) so that the ratio of frequency to voltage (V/F) is kept constant when the frequency is changed. General-purpose magnetic flux vector control The inverter under this control method compensates for the output voltage to provide a motor with the current which meets the load torque. This control mechanism results in the improvement of the motor torque at low speeds.
The output frequency is also compensated (slip compensation is performed) by setting parameters for slip compensation ( Pr.245 to Pr.247 ) to bring the actual motor speed closer to the commanded speed. This control method is useful when the load fluctuates are severe. • General-purpose magnetic flux vector control requires the following conditions. occur. If the conditions are not satisfied, select V/F control. Otherwise, malfunctions such as insufficient torque, uneven rotation may • The rated motor current should be equal to or less than the inverter rated current.
(It must be 0.4 kW or higher.) If a motor with substantially low rated current compared with the inverter rated current, however, is used, speed and torque accuracies may deteriorate due to torque ripples, etc. As a reference, select the motor with the rated motor current that is 40% • Set Pr.82 and Pr.90 properly according to the motor to be used. or higher of the inverter rated current. Single-motor operation (one motor to one inverter) is performed. • The wiring length from inverter to motor is 30 m or less. (When the wiring length exceeds 30 m, perform offline auto tuning with the wiring in place.) 84 5. PARAMETERS 5.2 Control method NOTE