Technology Trends in Variable Frequency Drives

Terry Webb

Engineering Manager, AC Drives

Fuji Electric Corp. of America

Fuji Electric History

1923

Established

alliance between Furukawa Electric Co., Ltd. and Siemens AG.

1954

Started ultra-compact magnetic switch production

1975

general-purpose inverters

1985

mini UPS

1,000kW phosphorus acid fuel cells

1991 1995

World’s first linear-motor-driven vertical transport systems

1999

mini-UPS

2010

1953

Semiconductor mass production

3-level converter & power module circuit for high efficiency electric power conversion

2011

Level 2 DC fast charger for electric vehicles

IGBT Production 1988

Power Integrated Modules (PIM)

IGBT Modules

AC Drive Technology

Progress of drive technology follows the progress of the power electronics technology!

Control Interface & Processor

Intelligent Power Module

4

Consumer

Data

Saver

Inverter

EV/HEV

Robot

UPS

Wind Power

Traction

MEGA Solar

Current Market

Expanding Market＿

（High Power / High Voltage）

Expanding Market (Small Power)

High Voltage（Ｖ）

Hig

h C

urre

nt

（Ａ）

IGBT Market

Market Demands - over the past 20 years continue today

• Power Conversion Equipment (e.g. GP Drives, UPS, etc.)

– Higher energy efficiency

– Smaller size

– Lower cost

– Less noise

– Less weight

• Variable Frequency Drives – Higher speed

– Higher accuracy

– Safety

– Lower Total Cost (system development, ease of installation, use, maintenance)

• Power Electronics (IGBTs)

– Higher performance

– Lower cost

– Higher reliability

– Higher power handling

– Advanced functions

5th Generation U-Series - 2003

– Trench and Field Stop (FS) Structures

– Based on trench-type power MOSFETs

1. Lower loss by the IGBT (30% less)

– Improve controllability of speed for turn-on, turn-off, and reverse recovery

2. Parallel connections

– Free Wheeling Diode (FWD) – reduce distribution in forward voltage

– Improved performance at low frequency, high torque range of ACDR when thermal duty

is high

3. Low EMI Noise

– Match IGBT & FWD

IGBT-PIM with 6th Generation Chip & Package Technology – V Series

• IGBT-PIM (Power Integrated Module) continued

– Inverter circuit

– Dynamic brake circuit

– Rectifier diode

• Advantage in size, easy assembly, economical

• Key technology is reduction of silicon area while managing electrical and thermal

performance

• IGBT is center of this – requires the development of both chip and packaging technology;

improved power dissipation in a package having lower thermal impedance.

• Also need low noise radiation through switching power dissipation

• Deep Field Stop (FS) Structure – reduces device thickness

• Further reduction of losses

• Reduced on-state voltage

• Raised the maximum junction temp to 175 deg C

Multilevel Inverters – different topology

• Two (2) level inverter

– Pulse Width Modulation (PWM) generating pulses of ±Ed from the central zero point,

• Three (3) level inverter

– PWM generating pulses of ±Ed/2 and ±Ed from the central zero point

• We apply a reverse-blocking IGBT (RBIGBT) to circuits connected to the neutral

point to develop a module designed exclusively for A-NPC inverters.

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8

Reduces filtering Higher power

SiC-SBD Device

• High efficiency for motor drive is pushing the development of sic-SBD with inverter.

• SiC-SBD devices are the next-generation SiC devices that significantly exceed the performance limits of the Si devices.

• high voltage

• high voltage low loss,

• high temperature

• power module, you apply the SiC-SBD FWD （Free Wheeling Diode） （ Insulated Gate Bipolar Transistor ） Si-IGBT with, applicable to General-purpose inverter.

• SiC-SBD's, features a small reverse recovery current switching time. This results in an IGBT with less switching loss and reduced reverse recovery losses for the FWD.

• Development of GaN （ gallium nitride ） （ silicon carbide ） SiC devices as the next-generation devices to dramatically reduce the loss beyond Si device characteristics. Advanced SiC Schottky barrier diodes

• Currently planning early mass-production SiC MOSFETS.

– Integrated module technology for high heat through the use of heat resistant epoxy resin copper pins, for bonding SiC module and thermal insulation board

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9

All SiC Module Si IGBT + SiC SBD Module

Reducing power-loss by SiC inverter

• SiC-SBD equipped with inverter and inverter models have achieved 25% reduction in switching loss • 3-phase 200V and 400V series 750-15 kW

Schottkey barrier diode

10

Silicon Technology : 7G-IGBT

7th-gen.

Current Density

100

120

160

Over 200??

Y2010-2012 development

Increase in watts density

or Improve efficiency

Next Generation Power Module

1. Silicon IGBT Module as Mainstream (7G-IGBT + 7G-FWD)

• High efficiency

– Power dissipation : 10-15% reduction

• Higher Temperature – 175-200oC

• Low thermal impedance : Rth10% reduction and thermal management

• High reliability & Longer Life

– Improve thermal cycling capability

2. Hybrid Module (V-IGBT+SiC-SBD)

3. New material WBG device ; All SiC (SiC-MOS + SiC-SBD w/ new pkg.)

• Excellent efficiency

– Power dissipation : 20-50% reduction

• High Temperature - 200oC

– Low thermal impedance : 50% reduction w/ new pkg.

• High reliability & Longer Life

– More improvement with new pkg.

12

Developed Hybrid Module

Power Integrated Module: PIM

all Si all Si Si-IGBT+SiC-SBD

Module Type: PIM with inverter, converter and brake

Chip Set: one IGBT + paralleled SiC-SBDs on one arm

SiC-SBD: development on FE and National Institute

IGBT: V-series IGBT (most recent gen. IGBT in FE)

Rating: 50A / 1200V (representative)

Reference: all Si module assembled in same package

13

Thick copper foil DCB

copper foil

copper foil

ceramic

Thick copper foil DCB

copper foil

copper foil

ceramic Conventional low temp typeConventional low temp type

Silicon

Ag layer

Copper circuit

Silicon

Ag layer

Copper circuit

Ultra Sonic jointing

New Package Technology

Copper wire

bonding

Ceramics

Copper file

Copper file

insulation design technology Nano metal (SiC)

Life prediction

Thermal

management

(7G&SiC)

New electrode treatment

(7G&SiC)

Cu pin

technology (SiC)

Insulating substrate (7G&SiC)

High voltage

High current

High Electrical Density & High Heat dispassion

High reliability

More Power! More

Circuit design Package design

Material Technology

Wide thermal

range operation

Wide temp. range Si Gel

(7G&SiC)

Improved Durability in Overload Operation

Sensorless Vector Control (w/PM motor)

• Accurate torque & speed control

– Position & speed estimator uses a voltage equation model

– Torque is calculated from precise estimates of rotor speed and magnetic pole

position from a voltage reference value and a current detection value

• Highly Efficient Operation

– Control torque with respect to current so that magnetic flux is always at the

maximum value

– Terminal voltage of PM motor < maximum output voltage of VFD

– Uses magnetic flux reference calculator and current reference calculator

• Auto-tuning (offline)

– Electric constants of PM motor (armature resistance, inductance and induced

electromotive voltage) must be known

– Automatically sets control parameters to optimal values based on measured

values of electrical constants.

– User no longer required to set parameters

Sensorless Vector Control (w/PM motor)

Sensorless Vector Control

• Add text as needed

Built-In Position & Vibration Suppression Control

• Servo positioning control function (low cost)

– Positioning control based on target position setting data (# of pulses) and deviation of

the detected position signal

– Equipped with return to origin function, over-travel processing, position preset function,

etc.

– I/O signals for:

• enable/disable positioning control input

• Position data selection input

• Position completed output

• Over-Travel detection

• Full closed control based on laser distance sensor

• Vibration Suppression Control

– Allows higher accel/decel for faster start/stop; high speeds; dwell

Built-In Position & Vibration Suppression Control

Fast, Accurate Assembly System

• Automatic Position Regulator (APR) and PG Vector Control

Better Winding Control

• Fast response using PID control based on dancer position

Built-in PLC Functionality

Pulse Train & Speed Ratio Operation

Safety (EN 954-1; IEC 60204-1)

• Category 0 (uncontrolled stop)

– Safety Signal input to dedicated safety terminal; Inverter turns off the torque (removes

power)

– Removal of power can be implemented with hardware only (without using software)

– Hardware removal circuit has a dual-system redundant design

Thank You