Hitachi SJ Series, User Manual

Page: 311 / 786

12-13-4
Chapter 12
Inverter Function
12.13.3 Controlling frequency to avoid
overvoltage
• Overvoltage error is generated when the motor is
decelerated.
• I want to decelerate the motor by automatically
extending the deceleration time.
• I want to prevent overvoltage error by increasing
the frequency when
regenerative load is applied.
• [bA140] overvoltage suppression function selection
allows you to enable the overvoltage suppression
function.
• The overvoltage suppression function will be
activated when the internal DC voltage of the
inverter main circuit capacitor exceeds the value
set by [bA141] overvoltage suppression level.
Parameters
• When this function is enabled, the actual
deceleration time may get longer than the set
value.
• When using this function, it may take long time
before the motor stops depending on the motor
load moment of inertia.
• Depending on the deceleration rate or load status,
the overvoltage tripping may be triggered even if
this function is enabled.
• Set [bA141] to be receiving voltage x
√
2 × 1.1 or
higher. Setting a value lower than the P-N voltage
in operation may prevent the motor from stopping.
Item Parameter Data Description
Overvoltage
suppression function
[bA140]
00 Disabled
01 Constant DC voltage-controlled deceleration
02
Function to avoid overvoltage acceleration (only
in deceleration)
03 Function to avoid overvoltage acceleration
Overvoltage
suppression level
setting
[bA141]
200 V class: 330.0 - 400.0
(V)
400 V class: 660.0 - 800.0
(V)
Sets the level at which the overvoltage
suppression function starts.
Overvoltage
suppression operating
time
[bA142] 0.00~3600.00(s)
Acceleration time when the overvoltage
suppression function is activated.
Constant DC voltage
control Proportional (P)
gain
[bA144] 0.00~5.00
Proportional gain for PI control in constant DC
voltage control.
Constant DC voltage
control Integral (I) gain
[bA145] 0.00~150.00
Integral gain for PI control in constant DC
voltage control.
Q
A
!