Starting With Active Frequency Matching - Hitachi WJ Series User Manual

Chapter 9
9.7.4

Starting with Active Frequency Matching

 How to start the inverter so that it quickly follows the command frequency regardless of the
Q
rotation speed frequency when the motor is idling?
 How to have the inverter follow the frequency command quickly during trip retry, free run stop,
reset, and supplying power, etc.?
 The active frequency matching restart function allows the motor to quickly pull from idle motor
A
rotation speed to a set frequency and restart while suppressing current increase. For more
details on this operation, refer to "(Example 1) Active frequency matching restart ".
 The active frequency matching function can be set for each of the following functions.
- Instantaneous power failure/undervoltage restart ([b001] = 04)
- Overcurrent/overvoltage restart ([b008] = 04)
- Restart after free-run release ([b088] = 02)
- Restart after reset release or powering-on ([C103] = 02)
 When restarting after free-run release or reset release, the inverter restarts once the free-run or
!
reset is released, and the standby duration set in the "Retry wait time after instantaneous power
failure/undervoltage error [b003]" since the RUN command turns on has elapsed.
 The active frequency matching restart function is only available with induction motor drives.
 When the RUN command input source is set to the RUN key on the keypad, the RUN command
is turned off when "Free run stop [FRS]" or "Reset [RS]" is turned on. If restart after free-run
release or restart after reset release is set, pressing the RUN key on the keypad to start operation
will start the retry operation. In case of an instantaneous power failure, undervoltage,
overvoltage, or overcurrent retry operation, the RUN status from the keypad is maintained.
Code
Active frequency
[b028] matching restart
level
Active frequency
[b029] matching restart
constant (speed)
Active frequency
[b030] matching restart
speed selection
◼
(Example 1) Active frequency matching restart
(1) Output will start at the frequency set
by [b030] after the retry wait time
elapses.
(2) Meanwhile, output power is gradually
increased to prevent the occurrence
of overcurrent and other issues.
(Dashed line in the figure on the left)
(3) If the output current exceeds [b028],
deceleration occurs in the output
frequency as per [b029] to suppress
the output current.
(4) Normal operation is possible when
the output frequency and output
voltage counterbalance each other.
Item
Sets the current limit value at the active
frequency matching restart.
Sets the deceleration time when the current is
increased.
Starts at the frequency of the previous output
interruption.
Starts at the maximum frequency setting.
Starts at the current command frequency.
Output frequency
Description
Interrupting
factor
Output
current
[b030]
(Output voltage
(dashed line))
Free running
Motor speed
Retry wait time after instantaneous power
failure/undervoltage error [b003]
9-7-4
Inverter Functions
Data
(0.2 to 2.0) × rated current (A)
(ND mode)
(0.2 to 1.5) × rated current (A)
(LD mode)
0.1 to 3000.0 (s)
00
01
02
Active frequency matching restart level [b028]
(1) (3)
(2)
Active frequency
matching restart
(4)