Suppressing Overvoltage By Controlling Output Voltage - Hitachi WJ Series User Manual

Chapter 9
9.9.4

Suppressing Overvoltage by Controlling Output Voltage

 How to avoid overvoltage errors that occur when the motor is decelerated?
Q
 How to increase the output voltage according to the regenerative power during deceleration
and decelerate the motor while avoiding the overvoltage error?
 When the control method is V/f control, output voltage can be controlled by the AVR function
A
using "AVR function selection [A081]
 Overexcitation of the motor during deceleration reduces regenerative energy to the inverter,
making it less likely to cause overvoltage error.
 Even when "Always enable (00)" is set, voltage exceeding the input voltage cannot be output.
!
 When the AVR function is turned off, the motor may generate more heat due to an increase in
output current caused by an increase in output voltage or due to overexcitation of the motor.
 Overvoltage trips may occur depending on the deceleration rate or load conditions.
Code
[A081] *1 AVR function selection
*1
[A082] Motor rated voltage
AVR function output
[A083]
filter time constant
AVR function voltage
[A084] gain during
deceleration
*1. "2nd-motor control [SET]" target parameter. The second control parameter is also subject to setting.
*1*2
".
Item
Always enable
Always disable
Disable during deceleration:
The motor become
overexcitation state only
during deceleration.
Sets the rated voltage of the
motor.
Filter time constant for the
output voltage at overexcitation
state.
Gain for the output voltage at
overexcitation state.
9-9-6
Description
Inverter Functions
Data
00
01
02
200 V class:
200/215/220/230/240
400 V class:
380/400/415/440/460/480
0.000 to 10.000 (s)
50 to 200 (%)