The output frequency is adjusted during ov suppression so that the DC bus voltage does not exceed the level set in parameter
L3-17. In addition to the parameters explained below, ov suppression also uses these settings for frequency adjustment:
• DC bus voltage gain L3-20
• Deceleration rate calculations gain L3-21
• Inertia calculations for motor acceleration time L3-24
• Load inertia ratio L3-25
Note:
1.
The motor speed will exceed the frequency reference when overvoltage suppression is triggered. Consequently, overvoltage suppression
is not appropriate in applications that require a perfect match between the frequency reference and the actual motor speed.
2.
Disable overvoltage suppression when using a braking resistor.
3.
Overvoltage may still occur if there is a sudden increase to a regenerative load.
4.
This function is enabled only when operating just below the maximum frequency. Overvoltage suppression does not increase the output
frequency beyond the maximum frequency. If this is required by the application increase the maximum frequency and change the base
frequency setting.
n
L3-24: Motor Acceleration Time for Inertia Calculations
Sets the time it takes to accelerate the motor from stop to the maximum speed at motor rated torque. This parameter should
be set when using KEB Ride-Thru 2, Intelligent Stall Prevention during deceleration (L2-04 = 2), or the overvoltage suppression
function (L3-11 = 1).
No.
Name
Setting Range
Default
L3-24
Motor Acceleration Time for Inertia Calculations
0.001 to 10.000
Calculations are made as follows:
L3-24 =
2 J [kgm
2
] n
[r/min]
60 T [Nm]
rated
rated
The rated torque can be calculated as follows:
60 P
[kW] 10
3
2
n
[r/min]
T [Nm] =
Motor
rated
rated
n
L3-25: Load Inertia Ratio
Determines the ratio between the rotor inertia and the load. Set this parameter when using KEB Ride-Thru 2, Intelligent Stall
Prevention during deceleration (L3-04 = 2), or the overvoltage suppression function (L3-11 = 1).
No.
Name
Setting Range
Default
L3-25
Load Inertia Ratio
1.0 to 1000.0
1.0
When set incorrectly, a fairly large current ripple can result during KEB Ride-Thru 2 and overvoltage suppression (L3-11 =
1) or other faults such as ov, Uv1, and oC may occur.
Parameter L3-25 can be calculated by:
L3-25 = Machine Inertia
Motor Inertia
u
L4: Speed Agree/Frequency Reference Loss Detection
These parameters set up the speed agree and speed detection functions which can be assigned to the multi-function output
terminals.
n
L4-01/02: Speed Agreement Detection Level and Detection Width
Parameter L4-01 sets the detection level for the digital output functions “Speed Agree 1”, “User Set Speed Agree 1”,
“Frequency Detection 1”, and “Frequency Detection 2”.
Parameter L4-02 sets the hysteresis level for these functions.
5.8 L: Protection Functions
202
YASKAWA
TOEP YAIQPM 03B YASKAWA AC Drive - iQpump Micro User Manual
Summary of Contents for iQpump Micro CIMR-PW Series
Page 443: ......
