YASKAWA Varispeed G7 Series Instruction Manual page 277

Control Method and Carrier Frequency Settings
Carrier frequency settings are restricted as listed in the following table according to the control method selec-
tion.
V/f control with or without a PG
Open-loop vector 1 control or
Open-loop vector 2 control
* The upper limit of the carrier frequency depends on the Inverter capacity.
Carrier Frequency Setting Precautions
When selecting the carrier frequency, observe the following precautions.
Do not change C6-02 (Carrier Frequency Selection) from the initial value when using flux vector control
•
mode (A1-02 = 3) or open-loop vector 2 control mode (A1-02 = 4) in applications with frequent starts and
stops, such as cranes and elevators.
If the carrier frequency is increased, the transistor inside the Inverter will be subjected to heat stress and
•
the service life of the Inverter may decrease.
You must take into consideration the selection of the Inverter capacity and the settings of the user constants
•
when changing the carrier frequency from the initial value to reduce the metallic noise of a motor.
Contact your Yaskawa representative for details.
Adjust the carrier frequency according to the cases shown below.
•
If the wiring distance between Inverter and motor is long: Set the carrier frequency low. (Use the following
values as guidelines.)
C6-02 (carrier frequency
selection) setting
If speed and torque are inconsistent at low speeds: Set the carrier frequency low.
If leakage current from the Inverter is large: Set the carrier frequency low.
If metallic noise from the motor is large: Set the carrier frequency high.
When using V/f control or V/f control with PG, you can vary the carrier frequency according to the output
•
frequency, as shown in the following diagram, by setting C6-03 (Carrier Frequency Upper Limit), C6-04
(Carrier Frequency Lower Limit), and C6-05 (Carrier Frequency Proportional Gain).
-44
6
Control Method
1: 2.0 kHz
2: 5.0 kHz
3: 8.0 kHz
4: 10.0 kHz
5: 12.5 kHz
6: 15.0 kHz
F: User setting*
Detailed settings are available in C6-03, C6-04, and C6-05.
1: 2.0 kHz
2: 5.0 kHz
3: 8.0 kHz
4: 10.0 kHz
Flux vector control 5: 12.5 kHz
6: 15.0 kHz
F: User setting*
The upper limit of the carrier frequency is determined by C6-03.
1: 2.0 kHz
2: 4.0 kHz
3: 6.0 kHz
4: 8.0 kHz
Wiring Length 50 m or less
1 to 6 (15 kHz)
Carrier Frequency
100 m or less Over 100 m
1 to 4 (10 kHz) 1 to 2 (5 kHz)