Fuji Electric V Series Instructions for use

© Fuji Electric Co., Ltd. All rights reserved.MT5F35778a
Application Manual
Fuji SiC Hybrid Module
V series
Nov. 2021

MT5F35778a © Fuji Electric Co., Ltd. All rights reserved. i
Warning:
This manual contains the product specifications, characteristics, data, materials, and structures as of
Nov. 2021.
The contents are subject to change without notice for specification changes or other reasons. When
using a product listed in this manual, be sure to obtain the latest specifications.
All applications described in this manual exemplify the use of Fuji's products for your reference only.
No right or license, either express or implied, under any patent, copyright, trade secret or other
intellectual property right owned by Fuji Electric Co., Ltd. is (or shall be deemed) granted. Fuji Electric
Co., Ltd. makes no representation or warranty, whether express or implied, relating to the
infringement or alleged infringement of other's intellectual property rights which may arise from the use
of the applications described herein.

MT5F35778a © Fuji Electric Co., Ltd. All rights reserved. ii
(1) During transportation and storage
Keep locating the shipping carton boxes to suitable side up. Otherwise, unexpected stress might
affect to the boxes. For example, bend the terminal pins, deform the inner resin case, and so on.
When you throw or drop the product, it gives the product damage.
If the product is wet with water, that it may be broken or malfunctions, please subjected to sufficient
measures to rain or condensation.
Temperature and humidity of an environment during transportation are described in the
specification sheet. There conditions shall be kept under the specification.
(2)Assembly environment
Since this power module device is very weak against electro static discharge, the ESD
countermeasure in the assembly environment shall be suitable within the specification described in
specification sheet. Especially, when the conducting pad is removed from control pins, the product
is most likely to get electrical damage.
(3)Operating environment
If the product had been used in the environment with acid, organic matter, and corrosive gas
(hydrogen sulfide, sulfurous acid gas), the product's performance and appearance can not be
ensured easily.
Cautions

MT5F35778a
1.
Maximum Junction Temperature
2-
2
2.
Short Circuit (Overcurrent) Protection
2-
2
3.
Overvoltage Protection and Safe Operation Area
2-
3
4.
R
GSelection
2-
7
5.
Parallel
Connection
2-
8
6.
EMI
2-
13
7.
Method
of Suppressing Waveform Oscillation
2-
14
Chapter 2 Precautions for Use
© Fuji Electric Co., Ltd. All rights reserved. 2-1

MT5F35778a © Fuji Electric Co., Ltd. All rights reserved.
1. Maximum Junction Temperature
2. Short Circuit (Overcurrent) Protection
In the event of a short circuit, first the IGBT’s collector current ICwill increase. Once it has reached a
certain level, the collector-emitter voltage VCE will increase suddenly. Depending on the device’s
characteristics, during the short circuit, the ICcan be kept at or below a certain level. However the
IGBT will continue to be subjected to a heavy load of high voltage and high current. Therefore, this
condition must be removed as soon as possible.
Fig. 2-1 shows the correlation between the short circuit capability (guaranteed short circuit withstand
time) and the applied voltage at the time of short circuit occurrence for the 1700V SiC hybrid module.
Set the short circuit detection time by referring to this graph as well as the operating conditions of the
application.
Fig.2-1 Relation between Short Circuit Capability and Applied Voltage
when Short Circuit Occurs in 1700V SiC hybrid module
2-2
The maximum junction temperature Tvj(max) is 150°Cfor all modules of Fuji’s 5th generation (U,U4
series). For the 6th generation (V series), it is increased by 25°Cto 175°C.
Taking into account of design margin the U and U4 series can be used at a continuous operating
temperature Tvj(op) of around 125°C. For the V series, continuous operation temperature of
Tvj(op)=150°C is guaranteed. This value is based on the verification tests conducted according to the
JEITA standards.
This increase in Tvj(op) contributes to downsizing of applicable module and heat sink, improvement of
output current and carrier frequency and expansion of the applicable range of inverter.
On the other hand, if the product is used above the maximum continuous operation temperature of
150°C, the power cycle capability may degrade and will lead to a reduced product lifetime.

MT5F35778a © Fuji Electric Co., Ltd. All rights reserved.
3. Overvoltage Protection and Safe OperatingArea
3.1 Overvoltage protection
Due to the fast switching speed of IGBT, high di/dtis generated during the IGBT turn-off and the
IGBT turn-on / FWD reverse recovery. This high di/dtcauses a high surge voltage due to the external
wiring stray inductance. If the surge voltage exceeds the module’s maximum rated voltage (VCES), it
can lead to the destruction of the module. There are several methods to suppress this overvoltage
such as adding a snubber circuit, adjusting the gate resistance RG,or reducing the inductance of the
main circuit.
To show the correlation between the surge voltage and the related parameters, an example of surge
voltage characteristics for the SiC hybrid module 2MSI400VAE-170-53 is shown.
Fig.2-2 shows an example of the dependency between the stray inductance and the surge voltage at
turn-off.As shown in the graph, the surge voltage increases as the stray inductance increases. It can
be seen that the effect on the turn-off surge voltage is particularly large.
Fig.2-3 shows an example of the dependency between the collector voltage and the surge voltage at
IGBT turn off. The surge voltage becomes higher when the collector voltage increases.
Fig.2-4 shows an example of the dependency between the collector current and the surge voltage at
IGBT turn off. The surge voltage at IGBT turn off will be higher when the collector current is larger.
As described above, the value of the surge voltage generated in IGBT modules varies greatly
depending on the main circuit stray inductance. Besides this, external circuit conditions such as
snubber circuits, capacitor values and gate drive conditions also have an influence on the surge
voltage.
When using IGBT modules, please make sure that the surge voltage is within the Reverse Bias
Safety Operating Area (RBSOA) under all operating conditions. If the surge voltage exceeds the
RBSOA, please take countermeasures such as changing the gate resistance, reducing the stray
inductance or adding a snubber circuit.
2-3

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Fig.2-2 Example of Stray Inductance Dependence of Surge Voltage at IGBT Turn-Off
Conditions
VGE=±15V
VCC=900V
RＧ=0.5Ω
Tvj=125°C
IC=400A
Fig.2-3 Example of Collector Voltage Dependence of Surge Voltage at IGBT Turn-Off
Conditions
VGE=±15V
LS=51nH
RＧ=0.5Ω
Tvj=125°C
IC=400A
Fig.2-4 Example of Current Dependence of Surge Voltage at IGBT Turn-Off
Conditions
VGE=±15V
VCC=900V
LS=51nH
RＧ=0.5Ω
Tvj=125°C
2-4

MT5F35778a © Fuji Electric Co., Ltd. All rights reserved.
3.2 Gate resistance influence on surge voltage during turn-off
In order to properly design the overvoltage protection, Fig.2-5 shows the relation between the gate
resistance RGvalue and the turn-off surge voltage VCEP for SiC hybrid module.
Generally, in order to suppress the surge voltage increasing the RGvalue has been a suitable
countermeasure. However, since the carrier injection efficiency has been improved starting with the 5th
generation (U series), the relation between RGvalue and the surge voltage has also changed.
Therefore, increasing RGvalue may now cause the surge voltage VCEP to increase, unlike the older
generation products.
Therefore, please select the RGvalue carefully during the design phase to match the requirements
and parameters of the actual equipment where the IGBT module is used.
Fig.2-5 Example of Gate Resistance Dependence of Surge Voltage at IGBT Turn-off
Conditions
VGE=±15V
VCC=900V
LS=51nH
Tvj=25°C
IC=400A
Reference
1) Y. Onozawa et al., “Investigation of carrier streaming effect for the low spike fast IGBT turn-off”,
Proc. ISPSD, pp173-176,2006.
2-5

MT5F35778a © Fuji Electric Co., Ltd. All rights reserved.
3.3 Overvoltage protection during short circuit current cut off
When a short circuit occurs, the collector current ICincreases sharply. In this case a larger IChas to
be cut off compared to a normal turn-off operation. Thus, an additional SCSOA (Short Circuit Safety
Operating Area) for non-repetitive pulse is defined for the short circuit condition.
Fig.2-6 shows the SCSOA and RBSOA for SiC hybrid module (1700V). For turn-off operation at short
circuit cut off, keep the operation trajectory of VCE-ICwithin the SCSOA. Note that SCSOA is defined as
non-repetitive whereas RBSOA is defined as repetitive.
Fig.2-6 RBSOA and SCSOA (1700V)
Conditions
VGE=±15V
RG≧RG(spec)
Tvj=150°C
2-6

MT5F35778a © Fuji Electric Co., Ltd. All rights reserved.
4. RGSelection
Standard gate resistance RGis indicated in the specification sheet.
Regarding the turn-on RG,the standard resistance value described in the specification sheet is
recommended, but it is necessary to confirm that the radiation noise stays within the allowable range.
Regarding the turn-off RG,as shown in Fig.2-7, increasing the RGmay cause the surge voltage to
increase, so it’s necessary to confirm that the surge voltage in the actual equipment is within the
allowable range.
Fig.2-7 Example of Gate Resistance Dependence of Surge Voltage at IGBT Turn-off
Conditions
VGE=±15V
VCC=900V
LS=51nH
Tvj=25°C
IC=400A
Reference
1) Y. Onozawa et al., “Investigation of carrier streaming effect for the low spike fast IGBT turn-off”,
Proc. ISPSD, pp173-176,2006.
2-7

MT5F35778a © Fuji Electric Co., Ltd. All rights reserved.
5. Parallel Connection
When using IGBT modules, they may be connected in parallel to handle larger output current. This
section describes the precautions for parallel connection of the SiC hybrid modules.
Fig.2-8 Junction temperature dependence of output characteristics（1700V/400A）
(b) Output characteristics of SiC-SBD(a) Output characteristics of IGBT
0
100
200
300
400
500
600
700
800
900
0 1 2 3 4 5
Collector Current: Ic[A]
Collector-Emitter Voltage: VCE [V]
T
j=25°C150°C
0
100
200
300
400
500
600
700
800
900
0 1 2 3 4 5
Forward current: IF[A]
Forward on voltage: VF[V]
T
j=25°C
150°C
2-8
5.1 Junction temperature dependence of output characteristics and current imbalance
The junction temperature dependence of the output characteristics has a big influence to the current
imbalance. Typical output characteristics of a 1700V/400A rated module are shown in Fig.2-8. The
temperature dependence of the V-IGBT and SiC-SBD used in the hybrid module is positive. Therefore,
the collector current decreases while the junction temperature increases. This will automatically
improve the current imbalance.
Therefore, all chips mounted in the hybrid modules have characteristics that are suitable for parallel
operation.

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5.2 VCE(sat)/VFvariation and current imbalance ratio
The ratio of current sharing, which occurs at parallel connection of SiC hybrid modules, is called
current imbalance ratio. This is determined by the variation in VCE(sat)/VFand the junction temperature
dependence of these characteristics.
Fig.2-9 shows the relation between typical variation of VCE(sat)/VFand current imbalance ratio. This
figure shows the current imbalance ratio for two parallel connected modules of V series IGBT and SiC -
SBD.As shown in the figure, it can be seen that the current imbalance ratio increases as the variation
of VCE(sat)/VFincreases. Therefore, when connecting in parallel, it is important to combine products with
small VCE(sat)/VFdifference (ΔVCE(sat)/ΔVF).
Fig.2-9 Variation and current imbalance ratio of VCE(sat)/VF(1700V/400A)
Conditions
VCC=900V
fSW=5kHz
Total IC=800Arms
Power factor=0.9
Modulation rate=0.8
2-9

MT5F35778a © Fuji Electric Co., Ltd. All rights reserved.
Supplement: regarding label notation of module characteristic data
The module's VCE(sat) and VFvalues are mentioned on the label. Good current balance can be
obtained by combining the same or close VFrank and VCE(sat) rank. Fig.2-10 shows an example of label
notation.
Notation contents :
-VCE(sat),VFvalues (ex. ‘211’= 2.105 ~ 2.114 V)
- Temperature code : R
- Product code
-Lot No.
- Serial No.
- Data matrix code
Fig.2-10 Notation example of characteristic data
2-10

MT5F35778a © Fuji Electric Co., Ltd. All rights reserved.
5.3 Current imbalance during switching
5.3.1 Main circuit wiring inductance variation
Inhomogeneous main circuit wiring inductance cause an imbalanced current sharing of parallel
connected modules.
Fig.2-11 shows the equivalent circuit at parallel connection in consideration with the main circuit
wiring inductance. If IC1 and IC2 flow through IGBT1 and IGBT2 respectively, the current sharing is
approximately decided by the ratio of main circuit wiring inductance, LC1+LE1 and LC2+LE2. So, the main
circuit wiring need to be designed as equally as possible in order to reduce current imbalance during
switching. However, even if ideal wiring inductance of (LC1+LE1) = (LC2+LE2)is realized, a difference
between LE1 and LE2 can cause current imbalance which is described below.
Inhomogeneous inductance of LE1 and LE2 will cause different induced voltage to generate even if
with the same di/dt. This difference in induced voltage affect the gate emitter voltages and will cause
current imbalance. This imbalance will increase the total collector current imbalance.
Therefore, it is extremely important to ensure the symmetry of the wiring structure for the collector
and emitter side separately: LC1 =LC2,LE1 =LE2.
Another point is to keep the inductance of the main circuit as low as possible because of the direct
correlation between inductance and surge voltage during turn-off. Place the paralleled modules as
close together as possible and design the wiring as uniform as possible.
If the IGBT module has an auxiliary emitter, it is recommended to drive the gate with this emitter
terminal in order to reduce the influence of the main circuit inductance.
Fig.2-11 Equivalent circuit at parallel connection in
consideration with main circuit wiring inductance
GDU
LC2
LC1
IGBT1
Rg Rg
IGBT2
LE2
LE1
IC2IC1
GDU
LC2
LC1
IGBT1
Rg Rg
IGBT2
LE2
LE1
IC2IC1
2-11

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5.3.2 Gate drive circuit
In the case of using separated gate driving units (GDU) for each IGBT, there is concern that the
switching timing may vary due to variations such as the delay time of the circuit. Therefore, it is
recommended that all the paralleled modules are driven by just one GDU. By using this setup, it is
possible to reduce the variation in switching time caused by the gate drive circuit. However, if the
modules in parallel are operated by the same driving circuit, there are concerns such as switching
speed is lowered due to insufficient drive capability. This may make the gate control impossible.
Therefore, please select the driver capability accordingly.
Also, when using a single gate drive circuit, parasitic oscillation may occur during rise of the gate
voltage depending on the wiring inductance and the IGBT input capacitance. Therefore, the gate
resistances of each IGBT should connected individually to the respective gates (please refer to Fig.2-
12). Also an additional emitter line resistor can help to suppress this oscillation. Keep in mind that the
voltage drop caused by these resistors may cause a device malfunction.
When the emitter wiring of the gate drive circuit is connected to different positions in the main circuit
wiring, LE1 and LE2 become unbalanced as shown in Fig. 2-11. This leads to an unbalanced transient
current sharing. Normally, IGBT modules have an auxiliary emitter terminal for the gate drive circuit,
and the internal drive wiring is even. Therefore, by using this auxiliary terminal to drive the gate,
transient current imbalance inside the module can be suppressed. It is recommended to drive the IGBT
with the auxiliary terminal.
However, even if the gates are driven by using the auxiliary emitter terminals, if the emitter wiring
from the gate drive circuit to each module is long and non-uniform, it will cause current imbalance..
Therefore, please make sure that the wiring of the gate drive circuit to each module connected in
parallel is the shortest possible with equal length. We recommend to use tightly twisted wires for the
gate drive circuit and keep them as far away from the main circuit wiring as possible. This will reduce
the possibility of mutual induction (especially by the collector current).
Fig.2-12 Wiring gate drive unit
GDU
IGBT1
Rg Rg
IGBT2
Extra emitter line
GDU
IGBT1
Rg Rg
IGBT2
Extra emitter line
2-12

MT5F35778a © Fuji Electric Co., Ltd. All rights reserved.
6. EMI
Fig.2-13 shows the radiation noise comparison of a 1700V SiC hybrid module with a conventional Si
module.
While the collector current decreases, the radiation noise increases for the conventional Si module,
whereas it decreases for the SiC hybrid module. In the region below 300A, the peak value of the
radiation noise of the SiC hybrid module is equivalent to that of the conventional Si module.
Fig.2-13 Collector current dependence of radiation noise
-60
-55
-50
-45
-40
-35
-30
0100 200 300 400
Amplitude [dBm]
Ic[A]
Si module
SiC hybrid
module
Reference
2) H. Wang, et al., “1700VSi-IGBT and SiC-SBD Hybrid Module for AC690V Inverter system”,
International Power Electronics Conference (IPEC-Hiroshima 2014-ECCE=ASIA), pp.3702-3706
2-13

MT5F35778a © Fuji Electric Co., Ltd. All rights reserved.
7. Method of Suppressing Waveform Oscillation
Fig.2-14 shows an example of the turn-off waveform of the SiC-SBD.
The waveform oscillation can be suppressed by adding a CR snubber between the collector and the
emitter of the hybrid module.
Fig.2-14 Suppression of waveform oscillation by CR snubber circuit
※Patent pending
(b) with CR snubber(a) without CR snubber
2-14