Download PowerAmerica Compliance 3rd Quarter DOE Review

Annual Meeting
Transphorm
Peter Smith, Yifeng Wu, Zhan Wang, Feng Qi,
Ricardo Pregitzer, Jason Cuadra,
Rakesh Lal & Primit Parikh
January 17-19, 2017
December 8 2015
Company Profile: Role in WBG Technology
Transphorm- Pioneering leader in high voltage GaN
Telecom/Industrial
Power supplies
Epi technology
Wafer fab
Renewable Energy
Solar inverters
Industrial
Motor drives/servo
Automotive
EV and charging
Applications-driven
resources
Power Devices
& Modules
Vertically integrated manufacturer and supplier of GaN WBG Solutions
2
5MHz Converter Circuit & Test
Demonstrates Transphorm’s reliable cascode switches operate fine at 5 MHz
Voltage waveform
Test circuit
(200V/400V, 5.1MHz, POUT=145W)
450
0.3µF
400
5µH
350
VIN
L1
VD
PWM/
Driver
Q1
300
CD
D1
COSS1nF
VOUT
C4
C2
VD (V)
C1
250
200
t1
15ns
t2
60ns
t3
60ns
t4
60ns
150
100
50
0.3µF
T
195ns
0
-50
0
0.05
0.1
0.15
0.2
0.25
0.3
t (µs)
 Boost converter in resonant mode to mimic device performance in flyback
converters (the main difference is coupled inductor in flyback converters).
 Air-core inductor sized to resonant with device output capacitances (COSS & CD) at
~5MHz.
 Energy transfer times (t2+t3)=120ns=0.62T, reasonable ratio at such high frequency.
 (Circulation current)/(Main conduction current): 0.6A/2.3A=26%, also reasonably low.
Jan 19, 2017
Task #: 2.6.1.3
3
Accomplishments BP1-2: 700V Inverter with 900V GaN
Inverter: 720VDC-500VAC
at 100kHz
99
100
98
80
97
60
96
40
95
20
94
0
2000
Loss (W)
Efficiency
Output waveform
0
4000
Power (W)
900V GaN Switch demonstrated – passing HTRB 720Volts, prelim datasheet done
Jan 19, 2017
Performer/Task #: Transphorm/2.6.2.3
4
Accomplishments BP1-2: Stable FQS/Bidirectional GaN Switch
and AC-AC Converter
Vo
Load
220V AC
Cfo
Q12
Lf
Cd
Vin
SO-16 package
Q34
Cfi
180V~300V AC
AC
Input Power v.s. Efficiency <G6E001-4>
98.00%
Efficiency
96.00%
94.00%
92.00%
90.00%
88.00%
86.00%
0
20
40
60
80
100
120
Input Power (W)
FQS/Bidirectional switch enables 2-4x part count reduction/low on-resistance
Initial design & prototyping work done in ARPA-E Solar ADEPT project – robust edge termination validated in PA project
5
BP2 Project Objectives
Project Title: Modular Open-Source Compact Transformerless Grid-Tied 3kW GaN PV Inverter
Major Milestones: Open source system design, core power blocks proto (3mo); H/W & F/W
integration (6mo); Grid sync & core PV inverter validated (9mo); Beta system tested (12mo)
Deliverables: Open source design of the PV inverter, 2-3 sets of modules with GaN switches, 1-2
sets of 3 kW PV inverters
Focus of work in Q1 & Q2
Focus of work in Q2
Accelerate adoption of WBG GaN with full reference design: 3-5 kW PV
Jan 19, 2017
Performer/Task #: Transphorm/4.18.1.1
6
Review of Existing Technology
Specification
Technical data
Input (DC)
Max. usable DC power [W]
Max. DC voltage [V]
Rated MPP voltage range [V]
MPPT operating voltage range [V]
Min. DC voltage / start voltage [V]
Max. operating input current per MPPT [A]
Max. short circuit current per MPPT [A]
Number of MPPT tracker / string per MPPT tracker
Values
240 V
3100
600
155 - 480
100 - 550
100 / 125
10
18
2/1
Output (AC)
AC nominal power [W]
Max. AC apparent power [VA]
Nominal voltage [Vrms]
AC voltage range [Vrms]
AC grid frequency [Hz]
Max. output current [Arms]
Power factor
Output phases / line connections
Harmonics
3000
3000
240
211 - 264
60 / 50
12.5
1
1/2
<4 %
Efficiency
Max. efficiency
CEC efficiency
97.6%
96.5%
Current inverters on the market (Single Phase, e.g. SMA, ABB, Fronius, Kaco)
Jan 19, 2017
Performer/Task #: Transphorm/4.18.1.1
7
Comparison of Typical Inverter Topologies
Properties
Simplicity
Cost
Switching Losses
Overall part counts
Efficiency
Output filter size & cost
Overall size & cost
EMI issues
Unipolar
Bipolar
3 Level NPC
+
+
+
+
+
+
+
+
+
+
-
Common mode current injection
-
Control system complexity
+
+
+
-
-
+
+
+
+
+
+
+
-
Except for common mode current injection issues, unipolar PWM is the best solution
Jan 19, 2017
Performer/Task #: Transphorm/4.18.1.1
8
Target Specifications of GaN Open Source PV Inverter-1
Output
Input
Parameter
Value
Comment(s)
Max usable input power
4200 W
Will be a stretch for passively cooled design
Number of MPPTs | Strings per MPPT | Peak power
per MPPT
2 | 1 | 2300 W
Cost goes up but 2 MPPT desirable for system
performance & availability
Max DC voltage at the input of a MPPT
600 V
Maximum open load panel string voltage
MPPT operating voltage range | Nominal MPPT
operating voltage
200-500 V | 360 V
Voltage range could be lowered for 3 kW design
Min DC voltage | Start voltage
80 V | 100 V
Startup with limited output power
Max input operating current per MPPT
11.5 A
Max input short circuit current per MPPT
12.5 A
Max power out at 240 VAC 1φ | Max apparent
power
4200 W | 4200 VA
Nominal output AC voltage | AC voltage range
240 V | 211-264 V
Power derating to start below nominal AC voltage
Max output current | Output short circuit current
17.5 A | 22.5 A
Electronic & circuit breaker! Cost!
Nominal AC grid frequencies
50 Hz / 60 Hz
Max DC current injection into grid
87.5 mA
0.5% of rated RMS output current
Max harmonic content of current injected into grid
< 3 % upto 25th
harmonic
Under non-distorted AC voltage conditions
Electronic & circuit breaker! Cost!
Target Specifications of GaN Open Source PV Inverter-2
Protection
η
Environmental &
Physical
Parameter
Value
Ambient temperature
-20C...+60C
Natural
Convection
Cooling
Comment(s)
Output power derating after 45C
Weight
<=6kg
Electronics, Heatsink. Estimated guideline
by one customer
Dimensions
TBD
Firmed up once boards are ready/tested
Max efficiency
99%
Not firm target. Cost takes priority
CEC efficiency
98%
Not firm target. Cost takes priority
Ground fault detection & turn-off current
300mA / 30mA
step
Need to decide if part of core power block
Arc fault detection & anti-islanding protection
This would be done by end users
 By enabling higher frequency operation with lower losses in the switches, GaN
power switches enable lighter & compact passively cooled PV inverters.
 Furthermore, GaN switch based converters have better efficiency at lower
power levels, which increases the diurnal operating time & energy harvested.
Jan 19, 2017
Performer/Task #: Transphorm/4.18.1.1
10
Overall System Block Diagram
Jan 19, 2017
Performer/Task #: Transphorm/4.18.1.1
11
DC-DC Boost Converter Prototype
 Two phase CRM boost topology
 Lower ripple through DC link
capacitors  improved life time &
reliability
 A 2.2 kW prototype built
 will be scaled up in the final design
to 2x2.2kW
 Efficiency measurements done
Input Voltage Efficiency
165VDC
210VDC
260VDC
98.37%
98.72%
98.95%
Note: These η achieved without
any switching algorithm
optimization; η> 99% possible
165VDC measurement taken at 250kHz switching, 330VDC/2 kW output
Jan 19, 2017
Performer/Task #: Transphorm/4.18.2.1
12
DC-DC Boost Efficiency Curves
Low Power Curves
High Power Curves
MPPT: Two modes of operation for higher efficiency over a larger power band
Jan 19, 2017
Performer/Task #: Transphorm/4.18.2.1
13
DC-AC H-bridge Inverter Prototype Grid-tied operation
 H-bridge inverter topology
 Simple, low cost, reliable  work in progress for EMI
mitigation with unipolar switching
 A 1.5 kW prototype was built first
 Basic hardware only  will be modified for 4.2 kW
 Different control algorithms tried
 Open loop with resistive load
Current: 1.25Apk
Prototype
Prelim test data
Showing excellent current
waveform for even low
power levels [when unipolar
designs can give large
distortion of current
waveform]
Voltage: 125Vpk
14
4.2 kW DC-AC GaN Inverter design done
Additional CM filter if
needed
Jan 19, 2017
Performer/Task #: Transphorm/4.18.2.2
15
4.2 kW DC-AC GaN inverter prototype
Space for test filters
&/or MPPT on integration
Inverter undergoing tests for various input voltage and power levels
Challenges we expect are: (a) EMI due to fast switching; (b) stability under transient load
conditions; & (c) common mode current injection when PV module leakage to ground is high
Jan 19, 2017
Performer/Task #: Transphorm/4.18.1.1
16
Test of bridge – 600VDC & 30A
Yellow – Current 5A/div
Blue – Voltage 100V/div
Task partially completed, but steady state testing should be over by Jan 31, 2017
Jan 19, 2017
Performer/Task #: Transphorm/4.18.2.2
17
System Controller Board
Board with DSP controller for real time control of MPPT & inverter modulation & inter-block control
Jan 19, 2017
Performer/Task #: Transphorm/4.18.3.1
18
Block diagram of system for PV Inverter test
PA = One channel of a
power analyzer
PV
PA
PA
Emulator
PA
AC Grid
Emulator
* For a system with 2x MPPT a second
PV emulator/DC source would be needed
* A three or four channel power analyzer is
needed for measuring DC & AC V, I & P
Adapted from IEC62116
Jan 19, 2017
Performer/Task #: Transphorm/4.18.3.0
19
SOPO Milestone and Deliverable Status
MS No.
Description
Due
4.18.1.1
Commercial inverter teardowns,
finalized specification for GaN Inverter
4.18.2.1
Boost converter tested with 99%
efficiency
Status
Notes
Month 3
Completed
Proposed to increase power
range from 3kW (original) to 4.2
kW (wider market)
Month 6
Completed
Boost / MPPT done
EMI test to be done
4.18.2.2
Inverter tested with 99% efficiency
Month 6
In Progress
1.5 kW inverter tested;
4.2 kW inverter protyped &
under test
4.18.2.3
Boost + Inverter tested
Month 6
Not Done
To complete after inverter
testing, no issues anticipated
Jan 19, 2017
Performer/Task #: Transphorm/4.18.
20
Project Timeline (Actual project start- July 2016)
Jun
Subtask
4.18.1
Jul
Aug
Sep
Oct
Nov
Dec
Jan
Mar
Apr
May
Go-No-go
decision
Firm-up Specs, architecture & design
Subtask
4.18.2
Feb
Prototype & bench test
Subtask
4.18.3
GaN OS PV
Inverter
System integration & test
Subtask
4.18.4
Full Integration & Test
Existing technology review
Boost converter optimized
Paper designs
Inverter running
Powertrain system
integration
Simulations
Final mechanical layout
EMI pre-compliance
Documentation
First round of power train
design
Completed
Jan 19, 2017
Work in Progress
Risk of Delay
Performer/Task #: Transphorm/4.18.
Work not started
21
Broader Impact on the WBG Community
 Advances over SOA approaches: High frequency low loss GaN switches
enable 50% reduction in size with higher efficiency
 System cost reduction due to smaller heatsinks, filters and reduced BoM
(e.g. diode-free)
 Market segments impacted: 1-5 kW PV inverters & UPS, and motor drives
(with additional software)
 Potential for job creation: R&D workforce and substantial US production, end
system use in US
 Workforce Development and Training: WBGS aware engineers through
manufacturing and project execution in PV inverter production & installation
Timeframe for commercialization: 2017
(Enabled by Transphorm’s proven reliability GaN Platform)
Jan 19, 2017
Performer/Task #: Transphorm/4.18.
22
Market / Commercialization
World Single Phase PV Inverter Market
GaN Volume
Revenue
35,000
3,500
30,000
3,000
25,000
2,500
20,000
2,000
15,000
1,500
10,000
1,000
5,000
500
-
2009
Product
3kW PV Inverter /
Full Reference
Design
2010
2011
2012
2013
Customers / Partner
Targets
PV Inverter
manufacturers- US/WW
Inverter Rev, USD (M$)
Volume (kU)
3kW Equivalent Inverter Volume
2014
End User / End Customer
Target
PV System Installers/
Integrators in US – Solar
city, Sun Edison Solar World
Key Impact
Accelerate insertion of GaN in
Residential /small scale
commercial PV Market for US
National labs
Promote GaN standard for PV
Proposed effort accelerates insertion of GaN in the US residential / small scale commercial segment
while simultaneously creating broad based awareness through suitable partnerships with National labs.
All of the IP generated will be US based.
Jan 19, 2017
Performer/Task #: Transphorm/4.18.
23