Space Voltage Vector Control Mode - Kruger Ecowatt K320 Series Operation Manual

Ecowatt Drive K320 series
®

5.5.4 Space voltage vector control mode

The VFD also provides the space voltage control function. The space voltage control mode can
be used in cases where mediocre control precision is enough and in cases where the VFD
needs to drive multiple motors.
The VFD provides multiple V/F curve modes to meet different requirements. You can select
V/F curves or set V/F curves as required.
Suggestions:
For the load featuring constant moment, such as conveyor belt which runs in straight line,

as the whole running process requires constant moment, it is recommended to adopt the
straight line V/F curve.
For the load featuring decreasing moment, such as fan and water pumps, as there is a

power (square or cube) relation between its actual torque and speed, it is recommended to
adopt the V/F curve corresponding to the power of 1.3, 1.7 or 2.0.
The VFD also provides multi-point V/F curves. You can change the V/F curves output by the
VFD by setting the voltage and frequency of the three points in the middle. A whole curve
consists of five points starting from (0Hz, 0V) and ending at (motor fundamental frequency,
motor rated voltage). During setting, follow the rule: 0 ≤ f1 ≤ f2 ≤ f3 ≤ Motor fundamental
frequency, and, 0 ≤ V1 ≤ V2 ≤ V3 ≤ Motor rated voltage
Output voltage
V
b
Straight-type
Output voltage
100 % V
b
V3
V2
V1
f1
Torque -down V/F curve (power of 1.3)
Torque -down V/F curve (power of 1.7)
Torque -down V/F curve (power of 2.0)
Square-type
Output frequency
f
b
f
f2 f3
-60-
Basic operation guidelines
Output frequency
b
Hz