evaluation of gan based h-bridge and half- bridge resonant ... · 1/11/2019 copyright © 2015...
TRANSCRIPT
Evaluation of GaN based H-Bridge and Half-
Bridge Resonant Converters in Capacitive-
Coupled Wireless Charging
Paul Han, Weiqiang Chen, Ali Bazzi, Ph.D
Advanced Power Electronics and Electric Drives Lab (APEDL)
ECE Department and Center for Clean Energy Engineering
10/16/2015
11/11/2019 Copyright © 2015 – Advanced Power Electronics & Electric Drives Lab (APEDL)
1/11/2019 2Copyright © 2015 – Advanced Power Electronics & Electric Drives Lab (APEDL)
Table of Content
• The Problem: Inductor Coupling
• The Solution: Capacitive Coupling
• Current Status: Conventional Silicon based Topologies
• Goal: Testing of GaN MOSFET based H-bridge and half bridge
• Proposed Design: GaN MOSFET Drive and PCB Schematic
• Difficulties: Designing PCB for 2Mhz operation
1/11/2019 3Copyright © 2015 – Advanced Power Electronics & Electric Drives Lab (APEDL)
The Problem: Inductive Coupling
• Current wireless charging solutions
for consumer electronics utilize
inductive charging. (Qi charging,
Powermet, etc.)
- Requires bulky and expensive
copper transmit and receive
coils
Mobile phone wireless charging pad
Qi charging pad
Wireless charging pad diagram
1/11/2019 4Copyright © 2015 – Advanced Power Electronics & Electric Drives Lab (APEDL)
The Solution: Capacitive Coupling
• Wireless charging based
on capacitive coupling
- Air capacitor formed by
plates on transmitter and
receiver
- Potential for slimmer
designs and simpler
manufacturing process
(e.g. metal coated plastic)
• Previously applied in
implanted medical device
charging (e.g. pacemaker)
and inter-PCB power and data transfer
• Our contribution to body of knowledge
- Performance comparison between H-
bridge and half bridge topologies in
transmitter driver
1/11/2019 5Copyright © 2015 – Advanced Power Electronics & Electric Drives Lab (APEDL)
Current Status: Conventional Silicon
based Topologies
H-Bridge System:
Half-Bridge System:
DCLoad
S1
Diode Rectifier
CapacitiveInterfacing
S2
S3
S4
H-bridge
L1
L2
R1
R2
D1
D2
D3
D4
DCLoad
Half-bridge Diode Rectifier
CapacitiveInterfacing
S1
S2
C1
C2
L1
L2
R1
R2
D1
D2
D3
D4
1/11/2019 6Copyright © 2015 – Advanced Power Electronics & Electric Drives Lab (APEDL)
Current Status:Testing of Silicon
MOSFET H-bridge and Half Bridge
• Computer modeling
• MATLAB Simulink
• Prototype
• Wire wrap construction
• 200kHz operation
• 60v input
• Resistive 10W load
Current Status: Matlab Simulink
1/11/2019 7Copyright © 2013 – Advanced Power Electronics & Electric Drives Lab (APEDL)
• Efficiency calculated based on input/output power
• Simplified MOSFET model based on conduction losses only
Current Status: Prototype
1/11/2019 8Copyright © 2013 – Advanced Power Electronics & Electric Drives Lab (APEDL)
• Prototype • Function generators
used for gate drive • 10W Resistive load• Efficiency calculated
using input/output power
• Note: Buck converter omitted
Current Status: Prototype Results
1/11/2019 9Copyright © 2013 – Advanced Power Electronics & Electric Drives Lab (APEDL)
H-bridge System
Blue: H-bridge output voltage
Red: Tank voltage
H-Bridge SystemGreen: Tank Current
1/11/2019 10Copyright © 2015 – Advanced Power Electronics & Electric Drives Lab (APEDL)
Goal: Testing of GaN MOSFET based
H-bridge and Half bridge
• Benefits
• Low losses• Low output and input
capacitance
• Eliminates reverse recovery loss
• Low switching losses
• High frequency operation• Goal of 2Mhz operation (old
100kHz)
• Allows for small components, lower losses, greater range
• Simulations predict efficiency of 90% for H-bridge, 95% for Half bridge
• Detriments
• Expense
• Difficulties of designing PCB for
high frequency operation
• No experience
1/11/2019 11Copyright © 2015 – Advanced Power Electronics & Electric Drives Lab (APEDL)
Proposed Design: GaN MOSFET
Drive
DC/DC Converter& Supply Isolator
Voltage Regulator+9V
+7V
+5V
Digital Isolator
Gate Driver
GaNMOSFET
1/11/2019 12Copyright © 2015 – Advanced Power Electronics & Electric Drives Lab (APEDL)
Proposed Design: PCB
Schematic
Voltage Regulator
+9V
+7V
+5V
Power Supply
DC/DC Converter& Supply Isolator
1/11/2019 13Copyright © 2015 – Advanced Power Electronics & Electric Drives Lab (APEDL)
Proposed Design: PCB
Schematic
Gate Driver
Power Stage and Drive Circuit
Digital Isolator
+7V
PWM input Port
H-bridge
Half-bridge
Rectifier
Rectifier
CapacitiveInterfacing
CapacitiveInterfacing
Gate-driver
1/11/2019 14Copyright © 2015 – Advanced Power Electronics & Electric Drives Lab (APEDL)
Difficulties: Designing PCB for 2Mhz
operation
• Current ideas
- 4 layer board (separate power and signal grounds)
- Metal shielding of h-bridge and half bridge
- Equal length traces
• Tips from articles- Keep analog, digital and power supply separate in board
- Steady signal flow from left to right
- Start locating critical components
- Bypassing the power supply into high speed circuity by using parallel
capacitors- In high frequency circuits, small parasitic can influence performance
- Consider skin effect: It causes current to flow in the outer surfaces of a
conductor – in effect making the conductor narrower, thus increasing the
resistance from its dc value
- Minimizing long parallel runs and close proximity of signal traces to reduce inductive coupling; minimizing long traces on adjacent layers to
prevent capacitive coupling