C
AE
E
G
Introduction of Auxiliary Emitter Resistors
•The introduction of REx (≈ 10 % of RGx) leads to– Limitation of equalising currents i ≤ 10 A– Damping of oscillations
V1V2 Vn
i ≤ 10 A
RE1
RE2REn
C
AE
E
G
Introduction of Auxiliary Emitter Resistors• The introduction of REx leads also to a
negative feedback:– The equalising current i leads to a voltage drop
VREx at the Emitter resistors REx
i
VRE1VRE2
fast IGBT slow IGBT
C
AE
E
G
Introduction of Auxiliary Emitter Resistors The introduction of REx leads also to a negative feedback:
The voltage drop VRE1 reduces the gate voltage of the fast IGBT and decreases therewith its switching speed.
The voltage drop VRE2 increases the gate voltage of the slow IGBT and makes it faster.
During switch off: vice versa.
i
fast IGBT slow IGBT
VRE1 VRE2
Additional proposals•The introduction of Z-Diodes – prevents over voltages at the gate contacts.– Therefore these clamping diodes must be placed very close to
the module connectorsC
AE
E
G
Additional proposals
• The introduction of Shottky-Diodes parallel to REx
– helps to balance the emitter voltage during short circuit case.– Dimensioning ≈ 100V, 1A.
Multi-level-inverter application
Topology of a multi level inverter (Three step)
Cells in series
Robicon princip
Rectifier Circuit : Simple diode rectifier with various three-phase windings 2Q Drive capabilityPatent rights: RobiconSemiconductors in use: standard IGBT + Diode arrangementTransformer in use: Different secondary windings, STAR, DELTA, Z, Number of Cells: number of cell in series 100% (as by Robicon)
Multi cell system like Robicon
Vienna rectifier with H-brigde
Rectifier Circuit :Vienna rectifier2Q Drive onlyPatent rights: Zener and Prof Kolar ETH ZürichSemiconductors in use: Not standard IGBT + Diode arrangementTransformer in use: All secondary windings are equalNumber of Cells: Same number of cell as by Robicon
Double booster with Multi level inverter
Rectifier Circuit : Three-phase PFC with doable booster2Q Drive onlyPatent rights: SEMIKRON InternationalSemiconductors in use: standard IGBT + Diode arrangementTransformer in use: All secondary windings are equal;Number of Cells: 1/2 number of cell as by Robicon
New SEMiX - FlexibilityMultilevel switch
New SEMiX Module with Semikron Patent
Halfbridges 2 x Choppers = Multi-Level-Modul
Multi-Level-leg with standard SEMiX module- Terminal GB module
+ Terminal
DC bus capacitor
Multi Level Inverter• Why multi level inverter
– All Semiconductors must have the half blocking voltage
– With Multi Level Topologies are high output frequency achievable
• Small output filter• 3 potentials available (+/-/centre point)• Minimization of rotor losses caused by current ripple• Through asynchronous clocking higher output frequencies
achievable
– EMC behavior• Potential difference only 50% of standard inverter• Reduction of audible motor noise• Reduction of ball bearing leakage current
EMC consideration during development of inverter
EMC Standards - GenericPrevious no.
Present no. Explanations and Remarks
EN 50081-1
EN 50081-1 Generic emission standard – Residential, commercial and light industry
EN 50081-2
EN 50081-2 Generic emission standard – Industrial environment
EN 50082-1
IEC/EN 61000-6-1
Generic immunity standard - Residential, commercial and light industry
EN 50082-2
IEC/EN 61000-6-2
Generic immunity standard – Industrial environment
- CISPR/IEC 61000-6-3
Generic standards – Emission standard for residential, commercial and light industrial environments
- IEC 61000-6-4 Generic standards – Emission standard for industrial environments
EMC Standards - Immunity TestsPrevious
no.Present no.
Explanations and remarks
IEC 801-2 IEC/EN 61000-4-2
Electrostatic discharge immunity test
IEC 801-3ENV 50140
IEC/EN 61000-4-3
Radiated, radio-frequency, electromagnetic field immunity test
ENV 50204 IEC/EN 61000-4-3
Radiated electromagnetic field from digital radio telephones – Immunity test
IEC 801-4 (1988)
IEC/EN 61000-4-4
Electrical fast transient/burst immunity test
IEC 801-5 (draft) ENV 50142
IEC/EN 61000-4-5
Surge immunity test
IEC 801-6 (draft)ENV 50141
IEC/EN 61000-4-6
Immunity to conducted disturbances, induced by radio-frequency fields
IEC/EN 61000-4-8
IEC/EN 61000-4-8
Power frequency magnetic field immunity test
IEC/EN 61000-4-9
IEC/EN 61000-4-9
Pulse magnetic field immunity test
IEC/EN 61000-4-10
IEC/EN 61000-4-10
Damped oscillatory magnetic field immunity test
IEC/EN 61000-4-11
IEC/EN 61000-4-11
Voltage dips, short interruptions and voltage variations immunity tests
IEC/EN 61000-4-12
IEC/EN 61000-4-12
Oscillatory waves immunity test
- CISPR 24 Information technology equipment – Immunity characteristics – Limits and methods of measurement
EMC Standards - Emission MeasurementsPrevious
no.Present no. Explanations and remarks
IEC 555-2EN 60555-2
IEC/EN 61000-3-2
Limits for harmonic current emissions(equipment input current ≤ 16 A per phase)
IEC 555-3EN 60555-3
IEC/EN 61000-3-3
Limitation of voltage fluctuations and flicker in low-voltage supply systems for equipment with rated current ≤ 16A
CISPR 11/EN 55011
CISPR 11/EN 55011
Industrial, scientific and medical (ISM) radio-frequency equipment – Electromagnetic disturbance characteristics – Limits and methods of measurement
CISPR 14/EN 55014
CISPR 14/EN 55014
Limits and methods of measurement of radio disturbance characteristics of electrical motor-operated and thermal appliances for household and similar purposes, electric tools and similar electrical apparatus
CISPR 22/EN 55022
CISPR 22/EN 55022
Limits and methods of measurement of radio disturbance characteristics of information technology (IT) equipment
Motor cable - correct
EMI rules I• Never put input and output together
– Input on top of the inverter– Output on bottom of the inverter
• Don’t use painted housings – bad connection
• Connect the isolation of transformers to ground
• Heatsink must be connected to the input terminals directly (PE)
EMI rules II• Use snubber capacitors to avoid voltage drop
in the DC-Bus voltage. Voltage drop will generate a very high dv/dt
• Use only freewheeling diodes with a soft recovery behavior
• Multi layer technology is avoiding stray inductance
Fast switching IGBTs• IGBTs generates a very high dv/dt
– Long motor cable • Isolation problems of the motor wire• Over voltage on the motor terminal through
reflections• Installation of special motor filter
– Capacitors generate leakage current• Sensitive short circuit monitoring• Higher switching losses• Installation of output reactor
– Ground connection• Bad ground connection generates higher noise
level by frequencies up to 2 MHz
EMC - Checklist• Did you connect all heatsinks with ground (PE)?– use a big surface for the connection (HF-current)– star connection– No painted surface - clean
• Did you install cores in the flatcables between controller-board and power stage
• Did you design a filter board between power stage and controller board?
• Did you use snubber capacitors on the +/- terminals?
• Did you use shielded cable between motor and inverter?– connect the shield on the heatsink and on the housing of the motor
• avoid arcing– check all screws– check the surface of the DC-bus-bars
SEMiX and Skyper
The platform idea
Pins for soldered driver
Springs for snap-on driver
Modular IPM
Sixpack Sixpack
The platform family (600 V, 1200 V, 1700 V)
All switch topologies available
Half bridge Chopper Sixpack
New driver concept “SKYPER”
• Reduced to basic functions
• 30% less components
• => less costs
• 2 IGBT-Driver versions: SKYPER™ + SKYPER ™
PRO
How to handle a IGBT
Information
How can we protect the gate?
Information
Gate Emitter Resistor
Gate clamping
IGBT Gate protection
How should we calculate the driver?
Proposal
Example for design parameters
• Which gate driver is suitable for the module SKM 200 GB 128D ?
Design parameters:
fsw = 10 kHz
Rg = 7
Demands for the gate driver
• The suitable gate driver must provide the required
Gate charge (QG)
Average current (IoutAV)
Gate pulse current (Ig.pulse)
• at the applied switching frequency (fsw)
-8
15
1390
Determination of Gate Charge
• Gate charge (QG) can be determined from fig. 6 of the SEMITRANS data sheet
QG = 1390nC
The typical turn-on and turn-off voltage of the gate driver is
VGG+ = +15V
VGG- = -8V
Calculation of the average current
• Calculation of average current:
• IoutAV = P / U U = +Ug – (-Ug)
• with P = E * fsw = QG * U * fsw
• IoutAV = QG * fsw
= 1390nC * 10kHz = 13.9mA
Calculation of the peak gate current
• Examination of the peak gate current with minimum gate resistance
E.g. RG.on = RG.off = 7
Ig.puls ≈ U / RG = 23V / 7 = 2.3A
Power explication of the Gate Resistor
• P tot – Gate resistor
– Ptot Gate resistor = I out AV x U
– More information:
The problem occurs when the user forgets about the peak power ratingof the gate resistor. The peak power rating of many "ordinary" SMD resistors is quite small. There are SMD resistors available with higher peak powerratings. For example, if you take an SKD driver apart, you will seethat the gate resistors are in a different SMD package to all the otherresistors (except one or two other places that also need high peak power). Theproblem was less obvious with through hole components simply because theresistors were physically bigger.
The Philips resistor data book has a good section on peak power ratings.
Choice of the suitable gate driver
• The absolute maximum ratings of the suitable gate driver must be equal or higher than the applied and calculated values
Gate charge QG = 1390nC
Average current IoutAV = 13,9mA
Peak gate current Ig.pulse = 2.3A
Switching frequency fsw = 10kHz
Collector Emitter voltage VCE = 1200V
Number of driver channels: 2 (GB module) dual driver
Comparison with the parameters in the driver data
sheet
Calculated and applied values:
• Ig.pulse = 2.3A@ Rg = 7
• IoutAV = 13.9mA
• fsw = 10kHz• VCE = 1200V
• QG = 1390nC
• According to the applied and calculated values, the driver e. g. SKHI 22A is able to drive SKM200GB128D
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