Hitachi WJ C1 Series User Manual

Chapter 9 Inverter Functions
9-9-4
9.9.3 Suppressing Overvoltage by Controlling Output Frequency
 How to avoid overvoltage errors that occur when the motor is decelerated?
 How to avoid overvoltage errors caused by regenerative voltage during deceleration by
automatically extending the deceleration time?
 The overvoltage suppression function can prevent the occurrence of overvoltage error during
deceleration.
 This function is activated when the DC bus voltage between the [P] and [N] terminals of the
inverter main circuit (P-N voltage) exceeds the overvoltage suppression active level setting.
 This function makes the actual deceleration time longer than the set value.
 Depending on the moment of inertia of the load, it may take a long time to stop.
 Overvoltage trips may occur depending on the deceleration rate or load conditions.
 The overvoltage suppression active level should be set to be equal to or greater than the input
voltage × √2 × 1.1. If a value lower than the P-N voltage value during operation is set, the
motor may not be able to stop.
Code
Item
Description
Data
[b130]
Overvoltage
suppression enable
Disable
00
Constant DC bus voltage control
(deceleration stop)
01
Enable acceleration
(during deceleration only)
02
[b131]
Overvoltage
suppression active level
Sets the operation level of the
overvoltage suppression function.
200V class: 330 to 400 (VDC)
400V class: 660 to 800 (VDC)
[b132]
Overvoltage
suppression active time
Acceleration time when the
overvoltage suppression function is
in operation.
0.10 to 30.00 (s)
[b133]
Constant DC bus
voltage control P gain
Proportional gain for PI control of
constant DC bus voltage control.
0.00 to 5.00
[b134]
Constant DC bus
voltage control I gain
Integral gain for PI control of
constant DC bus voltage control.
0.0 to 150.0 (s)
■ For Constant DC bus voltage control ("Overvoltage suppression enable [b130]" = 01)
 Constant DC bus voltage control automatically decelerates the motor while performing PI
control so that the P-N voltage remains constant during deceleration.
 Setting a larger proportional gain ([b133]) and a shorter integral gain ([b134]) will speed up the
response but make it more likely to trip.
Actual deceleration time
Overvoltage
suppression active
level [b131]
P-N voltage (VDC)
Time
Output frequency (Hz)
Deceleration starts
Time
Constant DC bus
voltage control
Deceleration time specified
at [F003]/[F203]
Q
A
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Hitachi WJ C1 Series Specifications

General

Brand	Hitachi
Model	WJ C1 Series
Category	Inverter
Language	English