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