5-16
If F05 is set to match the rated voltage of the motor, motor efficiency will
be better than that it is set to 0. Therefore, when brakes are applied to the
motor, energy loss decreases and the motor regenerates larger braking
energy, which can easily cause the overvoltage protection function (
0u
n
where n =
1
to
3
) to be activated. Note that the allowable power con-
sumption capacity of the inverter for braking energy is limited by the
specifications. If the overvoltage protection function is activated, it may be
necessary to increase deceleration time or use an external braking
resistor.
Non-linear V/f pattern for frequency (H50)
Sets the non-linear V/f pattern for frequency component.
(Setting 0.0 to H50 disables the non-linear V/f pattern operation.)
Non-linear V/f pattern for voltage (H51)
Sets the non-linear V/f pattern for voltage component.
If the rated voltage at base frequency (F05) is set to 0, the data settings of function
codes H50 and H51 will be ignored.
If you set the data of H50 to 25 Hz or lower (Operation under low base
frequency), the inverter output voltage may be limited.
Defining non-linear V/f patterns (F04, F05, H50 and H51)
Function codes F04 and F05 define a non-linear V/f pattern that forms the rela-
tionship between the inverter's output frequency and voltage.
Furthermore, setting the non-linear V/f pattern using function codes H50 and H51
allows patterns with higher or lower voltage than that of the normal pattern to be
defined at an arbitrary point inside or outside the base frequency. Generally, when a
motor is driven at a high speed, its internal impedance may increase and output
torque may decrease due to the decreased drive voltage. This feature helps you
solve that problem. Note that setting the voltage in excess of the inverter’s input
source voltage is not allowed. (For the single-phase 100 V class series, setting the
voltage that is two times or more the inverter's input source voltage is not allowed.)
Normal (linear) V/f pattern
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