Kinetic Energy Buffering - Omron VARISPEED F7 User Manual

Kinetic Energy Buffering

The kinetic energy buffering function can be used to decelerate to stop after a sudden power loss using the
kinetic energy of the rotating machine to maintain the DC bus voltage. Thereby an uncontrolled coasting of a
machine can be prevented. The function can be activated using a multifunction input i.e. can be operated by a
DC bus undervoltage alarm output or by a voltage drop relay. A wiring example is shown in
L1
L2
L3
Related Parameters
Parameter
No.
C1-09 Fast stop time
L2-01 Momentary power loss detection
L2-05 Undervoltage detection level
L2-08 Frequency reduction gain at Kinetic Energy Buffering start.
* 1. The values are for a 200 V class Inverter. Values for a 400 V class Inverter are double.
Setting the Momentary Power Loss Detection (L2-01)
L2-01 = 0
•
The inverter trips with undervoltage fault (UV1).
L2-01 = 1
•
No UV1 is detected within the time which is set in parameter L2-02. If this time is exceeded and the power
has not returned, an UV1 fault is output.
L2-01 = 2
•
No UV1 is detected. The inverter continues operation as long as the CPU is working.
To use the Kinetic Energy Buffering function in connection with the UV alarm output of the inverter, parame-
ter L2-01 must be set to 1 or 2.
Setting the Undervoltage Level (L2-05)
This parameter sets the voltage level for the DC bus at which a DC bus undervoltage (UV, UV1) is detected.
Normally there is no need to change this setting. If the UV detection is used for activating the Kinetic Energy
Buffering function, the UV detection level should be increased to the maximum to detect the UV as fast as
possible.
Terminal S3 to S7
Voltage drop relay
Fig 6.91 Wiring Example for KEB function usage
Name
Varispeed F7
H1- =66
SN
Change
Factory during
Setting Opera-
V/f
tion
10.0 s No A
0 No A
* 1
No A
190 V
100 % No A
Fig. 6.80.
to
Motor
Control Methods
Open Closed
V/f with
Loop Loop
PG
Vector Vector
A A A
A A A
A A A
A A A
131
6-
6