Yaskawa Electric Europe GmbH · Hauptstraße 185 · 65760 Eschborn · Germany · Tel. +49 (0)61 96/569–300
Frequently Asked Question
Topic:
How does the drive overload (oL2) detection of
V1000 work – Overview.doc
Author
YASKAWA
Product:
V1000
Date
13-Apr-2010
Keywords:
Drive overload, oL2, Derating
Pages
1 of 7
Distribution:
Customer
Internal Use only
The overload detection function (oL2 detection) protects the inverter from getting damaged due
to overload by calculating an I²t value. It works like shown in the block diagram on page 2.
The drive overload detection is active for output currents greater than 112% of inverter nominal
output current. The procedure is like follows:
•
The value of the output current from the current sensors (IAC) is increased artificially if
high carrier frequencies, high ambient temperatures or frequencies below 6Hz make a
derating necessary.
•
The difference to the overload protection starting current (112 %) is calculated ( ΔIAC ).
•
If Heavy Duty mode is active and the calculated current value is greater than 150% of
the drives rated current, the protection is once more strengthened. The ΔIAC value is
2
corrected by the formula ΔI AC _ new
•
ΔI AC
=
.
150% − 112%
The resulting (positive or negative) value will be integrated over time by adding it to the
values of the previous scans.
•
If the integral value exceeds the limit for HD or ND mode, an oL2 fault will be triggered.
How does the drive overload (OL2) detection of V1000 work - Overview - Rev. 1.doc
Yaskawa Electric Europe GmbH · Hauptstraße 185 · 65760 Eschborn · Germany · Tel. +49 (0)61 96/569–300
Carrier frequency
derating
Ambient
temperature derating
Low Speed oL2
reduction
State 1, if
C6-01 = 0 AND
IAC > 150 %
L8-15
0
IAC
*
1
ΔIAC2
150 % - 112 %
0
1
112%
Upper limit of
increased IAC value
Value depends on
drive size
Integrate amount of
current above 112%
Value depends on
L8-35
(120% - 112%) x 60 sec
(150% - 112%) x 60 sec
Upper limit of
integral value
1
C6-01
0
OL2
How does the drive overload (OL2) detection of V1000 work - Overview - Rev. 1.doc
Yaskawa Electric Europe GmbH · Hauptstraße 185 · 65760 Eschborn · Germany · Tel. +49 (0)61 96/569–300
Drive Overload detection time
The following diagrams show the oL2 detection curves for Heavy and Normal Duty.
Drive Overload detection time - Heavy Duty
OL2 Detection Time [min]
100
10
1
0.1
100.0
110.0
120.0
130.0
140.0
150.0
160.0
170.0
180.0
190.0
200.0
Output Current [%]
Drive Overload detection - Normal Duty
Overload Detection Time [min]
100
10
1
0.1
100
110
120
130
140
Output Current [%]
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The figure below shows how the oL2 detection works if the current is not continuously above the
oL2 detection level (112%). If the sum of all areas (a, b, c, …) becomes bigger than the A value
(150% - 112%) * 60s for ND or (120% - 112%) * 60s for HD, the inverter will trip with “oL2”. In
Heavy Duty mode, this calculation is only valid, as long as the output current is below 150%.
Iout
a
c
112%
b
if (a-b+c) > A
then "OL2" is detected
t
Example:
Heavy Duty is selected.
If a basic load of 100% and cyclic load peaks with 140%, 40 sec. are assumed, the minimum
possible cycle time can be calculated like follows:
(140-112)%*40sec=1120
140%
Areas must be
equal
112%
100%
40 sec
t
1120/(112-100)%=93.3sec
So the minimum cycle time for this condition is 133.3 seconds.
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Values for ambient temperature derating
Values for carrier frequency derating
The following diagrams show the derating values for high carrier frequencys for the different
drive sizes.
Heavy Duty
BA0010 to BA0016 and 2A010 to 2A0069
BA0001 to BA0006 and 2A0001 to 2A0006
1.2
1.2
1
1
0.8
Derating value
Derating value
0.8
0.6
0.6
0.4
0.4
0.2
0.2
0
0
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0 10.0 11.0 12.0 13.0 14.0 15.0
Carrier frequency (kHz)
Figure 1: 200V Single Phase 0.8 to 5.0 A
200V Three Phase 0.8 to 5.0 A
10 kHz without derating
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0 10.0 11.0 12.0 13.0 14.0 15.0
Carrier frequency (kHz)
Figure 2: 200V Single Phase: 8.0 to 17.5 A
200V Three Phase:8.0 to 60.0 A
8 kHz without derating
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VC4A0001 to VC4A0038
1.2
Derating value
1
0.8
0.6
0.4
0.2
0
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0 11.0 12.0 13.0 14.0 15.0
Carrier frequency (kHz)
Figure 3: 400V Three Phase: 1.2 A to 31.0 A
8 kHz without derating
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Normal Duty
In Normal Duty mode, in general derating has to be considered for carrier frequencys above
2kHz. The following diagrams show an overview for the range of the values for the different
drive sizes. The derating value is between the upper and the lower line.
Please contact YASKAWA if you need detailed data for certain drives.
200V Class Drives
Figure 4: Range of Derating Values for Normal Duty (200V Class)
400V Class Drives
Figure 5: Range of Derating Values for Normal Duty (400V Class)
How does the drive overload (OL2) detection of V1000 work - Overview - Rev. 1.doc