Losses And Efficiency Of A Motor; Losses And Efficiency Of A Power Drive System - Danfoss VLT DriveMotor FCP 106 Design Manual

System Integration
1.80
1.60
1.40
1.20
1.00
0.80
0.60
3 3
0.40
0.20
0.00
0 10
1 100% load
2 50% load
3 25% load
Illustration 3.14 Drive Power Loss Data.
CDM Relative Losses (P
(n) [% of Nominal Speed].
100.00
98.00
96.00
94.00
1
2
92.00
3
90.00
0
1 100% load
2 50% load
3 25% load
Illustration 3.15 Drive Efficiency Data.
CDM Efficiency (η
(n) [% of Nominal Speed].
Interpolation of power loss
Determine the power loss at an arbitrary operating point
using 2-dimensional interpolation.

3.7.4 Losses and Efficiency of a Motor

The efficiency of a motor running at 50–100% of the
nominal motor speed and at 75–100% of the nominal
torque is practically constant. This is valid both when the
drive controls the motor, or when the motor runs directly
on mains.
The efficiency depends on the type of motor and the level
of magnetization.
For more information about motor types, refer to the
motor technology brochure at www.danfoss.com. Search for
motor technology.
38
VLT
20 30 40 50 60 70
n [%]
) [%] versus Speed
L, CDM
20 40 60
n [%]
) [%] versus Speed
CDM(freq, load)
Danfoss A/S © 12/2018 All rights reserved.
®
DriveMotor FCP 106
Switching frequency
The switching frequency influences magnetization losses in
1
the motor and switching losses in the drive, as shown in
Illustration 3.16.
2
25
3
20
80 90 100
15
10
5
0
0
1
2
3
Illustration 3.16 Losses [%] versus Switching Frequency [kHz]
NOTICE
A drive produces extra harmonic losses in the motor.
These losses decrease when switching frequency
80 100
increases.
3.7.5 Losses and Efficiency of a Power Drive
System
To estimate the power losses at different operating points
for a power drive system, sum the power losses at the
operating point for each system component:
•
Drive
•
Motor
•
Auxiliary equipment
1
2
3
2 4 6
[kHz]
Motor and drive
Motor only
Drive only
8 10
MG03M302