Hitachi SJ300-037HFE Manual Do Utilizador

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SJ300 Inverter
Configur
ing Dr
iv
P
a
ra
met
e
rs
3–15
c. After reaching the base frequency, the characteristic maintains a constant output voltage 
for higher frequencies.
Using parameter A045 you can modify the voltage gain of the inverter. This is specified as a 
percentage of the full-scale setting AVR (Automatic Voltage Regulation) in parameter A082. 
The gain can be set from 20% to 100%. It must be adjusted in accordance with the motor speci-
fications.
Torque Boost – The Constant and 
Variable Torque algorithms feature an 
adjustable torque boost curve. When the 
motor load has a lot of inertia or starting 
friction, you may need to increase the 
low frequency starting torque character-
istics by boosting the voltage above the 
normal V/f ratio (shown at right). The 
boost is applied from zero to 1/2 the 
base frequency. You set the breakpoint 
of the boost (point A on the graph) by 
using parameters A042 and A043. The 
manual boost is calculated as an 
addition to the standard straight V/f line (constant torque curve).
Be aware that running the motor at a low speed for a long time can cause motor overheating. 
This is particularly true when manual torque boost is ON or if the motor relies on a built-in fan 
for cooling.
NOTE: Manual torque boost applies only to constant torque (A044=00) and variable torque 
(A044=01) V/f control.
NOTE: The motor stabilization parameter H006 is effective for constant torque (A044=00) and 
variable torque (A044=01) V/f control.
V/f Free-setting – The free-setting V/f inverter mode of operation uses voltage and frequency 
parameter pairs to define seven points on a V/f graph. This provides a way to define a multi-
segment V/f curve that best suits your application.
The frequency settings do require that 
F1 
≤ F2 ≤ F3 ≤ F4 ≤ F5 ≤ F6 ≤ F7; their 
values must have this ascending order 
relationship. However, the voltages V1 
to V7 may either increase or decrease 
from one to the next. The example to the 
right shows the definition of a complex 
curve by following the setting require-
ments.
Free-setting f7 (B112) becomes the 
maximum frequency of the inverter. 
Therefore, we recommend setting f7 
first, since the initial value of all default 
frequencies f1–f7 is 0Hz.
NOTE: The using of V/f free-setting operation specifies parameters that override (make 
invalid) certain other parameters. The parameters that become invalid are torque boost (A041/
A241), base frequency (A003/A203/A303), and maximum frequency (A004/A204/A304). In 
this case, we recommend leaving their settings at the factory default values.
f base = 
60Hz
Torque boost
A042 = 10
A043 = 10%
frequency
100%
10%
0
V
A
6.0Hz
30.0Hz
Output voltage
Output
frequency
(even)
B101 to
 B113
(odd)
B100 to B112
V7
V6
V5
V4
V1
V2, V3
0
f1
f2 f3
f4
f5 f6 f7 Hz