ST traction inverter system solution

June 2020

Control Board

Driver Board

Water Cooling

SiC Mosfet

Traction inverter system

2

The traction inverter converts energy from the vehicle's battery in order to

drive the motors in the drivetrain.

Traction motor

Traction inverter

demo

110 kW motor

control test bench

Motor control test bench

for traction inverter

System architecture

• MCU SPC58NN

• 3 core 200Mhz, 2core lockstep

• ISO26262 – ASILD

• SBC L9396

• Multiple Power Supply IC

• ASILD

• SiC MOSFET

• 750V 500A SiC MOSFETs Gen 2

• L9502 / STGAP

• Single isolated Gate Driver (6kv) for

Traction inverter with protection ,

diagnostics and communication

• Designed for ISO26262 compliance

LVBAT

VCUVoltage

regulator

Power supply protectionEMC filter

Can interface

Analog input

SPC58

VDD-HSVDD-LS

SPIINTWDIRST

ERROR

Driver temp*3Phase current UVW

EMCfilter

HVBAT

ASC

SPI

Gate signal

Motor temp

Currentsensor

Over current protection

Voc

Vref

Buffercircuit

Exc+Exc-

S1S2S3S4

HV

conn

ecto

r

U V W

Supplymonitor

VB

STV

CC

VC

C5

VP

RE

RE

G

VCORE

VCC5

VDD30VCC

VCC

BoostBuckLDO

L9396

Flyback

Three-phase bridgeSIC Mosfet & IGBT

Inverter Temp Sensor X3

Tsen

Gate signal

VDD-HSVDD-LS

conn

ector

L9502*6Capacitive Isolation

Phase current UVW

Digital input Air bagASC

VDD30

M

HV

conn

ecto

r

conn

ector

Ain

FSNASC

VH VLML

DISADC_OUT

AD

C_O

UT

DC-LINK Capacitor

DesatVCLBrake

Fault signal

ASCFW

Temp sampling

Analog sampling

SPIIN+IN-

Resolver & Temp sensor

3

Traction inverter system highlights

4

System highlightsoftware resolver

5

• Motor Axis Angle measurement is very important for motor efficiency and torque stability

• Resolver sensor of Motor Axis Angle measurement for higher accuracy and reliability

>$10

Resolver ASIC MCU

exciting

feedback

SPI

A,B,Z

Traditional solution (ASIC)

Resolver MCU

exciting

feedback

Cost down solution (software)

PWM

ADC

• Exciting & decoder algorithm implement in MCU

• Minimized discrete external signal condition circuit

System highlightperformance evaluate with hardware in loop

6

7

• Bench evaluation:

• traction motor: 50KW, <12000 rpm

• 4 pole pair resolver, 10KHz Frequency.

• 10 points digital sampling rate @integral algorithm

Electronic angle error

Good performance

• Real - Time < 2usec

SPC58NN + L9396+L9502+Sic MOS

Traction invertor

Motor Test Bench Traction motor

System highlightperformance evaluation on SPC58NN

System highlightfunctional safety

8

FTA

FMEDA

DFMEA

DFA

Safety Example Code

Design Verification and Validation Plan

Functional safety reference documents available

SW/HW requirement

Technical Safety Requirement

Function safety requirement

Safety Goal SG1

FSR 1.1

TSR1.1.1

SW requirement

HW requirement

TSR1.1.2 TSR1.1.3

FSR 1.2

Traction inverter system keycomponents

9

SPC58NN Traction inverter

Automotive ASIL-D

applicationsISO26262

GTM344 SVPWM

SDADC Resolver software decoding

SARADC

High accuracy current

sampling , temperature

sampling and high voltage

sampling

Flash : 6576KB OTA

8X SPI

8X CANFD

Communication between

micro and SBC, micro and

Pre Driver , micro and CAN

transceiver ,etc.

Support calibration , CAN

Bus Communication

MCU SPC58NN

10

SBC L9396

L9396 Traction inverter

LDO (5V, 250mA),

LDO (3.3V / 5V, 100mA),

VCORE (0.8V / 5V +/-2% -

µC core supply, max

1000mA in switching mode,

max 750mA in linear mode)

Power supply：micro

Analog chip

Pre driver chip

Voltage monitor

WD 2XSystem safety

HS Pre driver Cooling pump control

IGN input Hardware wake-up

SPI Communication (CRC)

Fault single output

FSN

Fault diagnosis and fault

protection

FAULT

WDTDIS

Voltage

Monitor

Wake-up

Monitor

IGN

Boost

Controller

9V

300mA

2MHzGNDBST

BSTSW

VBG

VBM

VBST

CPCharge Pump

GN

DA

ResetRESET

GN

D1

Control & Logic

Blocks

SPI

Ctrl/

Status

Reg.

Temp

Mon

Oper

Modes

Fail-

Safe OpFSN

WD

CSN

SDISDO

CLK

Int. analog

3V3 supply

Int. digital

3V3 supply

POR &

Osc.

Buck

6.5V / 7.2V

1000mA

465KHz

BCKSW

VPREREG

LDO VCC5

5.0V

250mA VCC5

LDO VCC

3.3V / 5.0V

100mA VCC

VCCSEL

VCORE

0.8V / 3.3V

1000mA

Buck w/ext FET

500mA

Lin w/ext. FET

VCOREFDBK

Fail Safe

FET

HS predr

Pump Motor FET

HS+LS pre driver

(PWM control)

PD

S

VDBATTWSS / TrackRegRSU0H/L

WS

O0

WS

O1

WS

O2

WS

O3

AI[0..4]

HV Mux +

ADC Converter

Battery protected

switch

VB VB_SW

Decoding

GCORE

VC1 VC2

PD

G

VDSVDG

SCORE

System

Voltages

LS GPO driver

(PWM control)

GPOD0

Voltage

regulation

Motor turn

counter in Low

Power Mode

VC3 VC4

I_CORE_SH

I_CORE_SL

VCORE

PRN

RSU1H/LRSU2H/LRSU3H/L

PR

S

PR

G

PR

I

PD

I PDBATT 11

ACEPACK drive

Direct liquid cooled high performance power module

Traction inverter for (H)EV, Trucks, Bus

Press FIT connections for high reliable and long-lasting connection

SiC-MOSFET based, 750V and 1200V

Pin-fin for direct cooling

Dedicated NTC for each single substrate

Unequalled RDS(on)

ACEPACKTM

DRIVE

Internal layout optimized for minimized stray inductace

High reliability and robustness: Dice sintered to substrate

Different bus bar available to fit welding or screwing connection methods.

AMB substrates for better thermal managment

Incredibile high power density

12

Isolated gate driver L9502

• 15A driver sink/source current capability

• Miller clamp

• Advanced Diagnostic and Protection

• 10-bit A/D Converter with 2 exteranl inputs

• BRAKE pin with programmable safe state

• 5MHz SPI interface with enhanced safety

• Output flyabck voltage 23V (-5V 18V; -8V 15V)

on L9502

Single channel isolated gate

driver

AEC-Q100 Grade 1

ASIL D systems ready

6kV galvanic isolation

Flyback controller on L9502

IGBT

13

Traction inverter system support package

14

• ST can provide a set of product application solutions

• MCU SPC58NN

• SBC L9396

• Pre driver L9502

• Pre driver STGAP

• Power module SiC MOSFET

• ST provides valuable application materials for customers

Support package

15

Design kit Validation report Functional safety 3rd party partners

• System architecture

• Requirements analysis

• Hardware schematic

• PCB,BOM

• Software • low level driver

• AUTOSAR complex driver

• AUTOSAR MCAL

• Double pulse test data

• Bench test data

• FTA

• FMEDA

• DFMEA

• DFA

• Safety example code

• Design verification and

validation Plan

• Vector

• ETAS

• EB

• Greenhills

• Hightec

• GIICS

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