Download Design Review - ECE Senior Design

Battery Energy Storage with an Inverter
that Mimics Synchronous Generators
Team 1508 Members
Nerian Kulla
Sabahudin Lalic
David Hooper
Faculty Advisor
Professor Sung-Yeul Park
To: ECE/CSE Faculty
ECE 4901
Design Review
11/11/2014
Outline
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Background Information
Project Goals
Key Specifications
Design
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DC/DC Design
DC/AC Design
Final Integrated Design
Budget
Time line
Background Information
IFEC, which stands for International Future Energy Challenge, is an
international student competition for innovation, conservation, and
effective use of Electrical Energy.
The main objective of this project is to:
• develop a grid-connected energy storage system with an inverter
that can mimic the functions of synchronous generators.
• able to autonomously deliver the right amount of real power and
reactive power according to the grid frequency and voltage or
• to regulate the frequency and voltage via changing the real power
and reactive power delivered.
Design a Battery that will supply
Power to a vehicle, as well as a
Power Grid.
Battery capability:
Bi-directional current flow
(Grid to Battery or Battery to
Grid)
Potentially fulfill the energy
storage needs of the electric
grid supplying ancillary services
• reactive power compensation
• voltage regulation
• and peak shaving
Project Goals
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Have the basic functions of charging,
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battery and the gird/load with high
discharging and protection for the battery
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efficiency
Meet the desired power quality to the
grid/load
Realize power conversion between the
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Achieve seamless transfer between gridconnected and stand-alone modes
Improve power density
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Reduce manufacturing cost
Key Specifications
Design
Requirements/Challenges:
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Needs to be bidirectional
It requires to Buck and Boost the voltage
Convert voltage from DC to AC
Convert voltage from AC to DC
Be within the budget
Be energy-efficient
Meet the specifications
Topology
DC-DC Converter
• Bidirectional Buck & Boost
converters
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Buck converter required to
lower voltage from 350V DC
to 48V DC
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Boost converter required to
increase the voltage from 48V
DC to 350V DC
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Uses a LC filter to conduct
buck and boost conversion
and regulate voltage/current
ripple
Topology
AC-DC Rectifier
• Rectifier Bridge
- Convert AC-to-DC
needed to charge
battery
- Input 230V AC and
outputs 325V DC
- Uses diodes to rectify
current from AC to DC
- Uses Inductor to filter
current ripple
- A DC link Capacitor
filter voltage ripple
Topology
DC-AC Inverter/AC-DC Rectifier
• Inverter Bridge
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Convert DC-to-AC
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Uses four Power MOSFET
switches
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PWM to control the
MOSFET
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LC filter for a clean B2G
AC waveform
Topology
Power Schematic
Bidirectional
AC-to-DC (Grid to Battery)
&
DC-to-AC (Battery to Grid) DC Link
Boost Converter
(Battery to Grid )
&
Buck Converter
(Grid to Battery)
Devices
• Switching Devices
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IGBT, MOSFET, GaN, etc.
• Sensors
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Current sensor, Voltage sensor
• Inductors
• Transformer
• Capacitors
Devices
Switches
• Active switches are used to invert DC to AC and convert DC to
DC for buck and boost mode using PWM
- Devices considered were the MOSFET, IGBT and GaN
Devices
Switches
• The device of choice is the Power MOSFET
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High switching frequency ( >200kHZ)
o
Reduces the size of the passive elements i.e.
Inductors, Capacitors
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Low switching power loss
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Low conduction resistance
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Low cost
Devices
Sensors
• Current Sensors
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Measure the input current and output current
o
Needed for the control stage
• Voltage Sensors
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Measure the AC Grid voltage, DC Link voltage
and Battery voltage.
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Needed to for feedback for the control stage
PCB Board
Using Altium Designer software, we plan on designing our PCB
board using the Top and Bottom layer for the components, as well
as a mid-layers for common connections, reduce noise levels, and
for High Current usage. (Power, Ground, etc.)
When building a PCB board, there are different things to
consider for the most efficient, safest and reliable Power usage.
Placing Components
• We give careful thought when placing components in order to minimize
trace lengths.
• We place Parts next to each other that connect to each other, which will
make laying out traces less difficult and more neat.
• Arrange components in a specific orientation (up and down, left and
right) for easier Pin connections.
Using complete planes for Power, Ground, etc.
Copper pours on signal layers are common in PCB’s:
• Can be a hatched ground pour an analog design
• Solid Power supply pour for carrying heavy currents
• Solid ground pour for EMC shielding
Track Design
• Determine standard track width ( avoid shorts occurring, number of
tracks used in an area)
• Consider track size for lines carrying current
• Determine pad shapes and sizes
Thermal Issues
With higher processing speeds and higher component densities, in
addition working with high voltages and currents, thermal issues should
be taken into consideration
It is important to allow sufficient space for cooling around hot
components.
It is also a good idea to leave extra space around components that
dissipate larger amounts of heat.
Timeline
Completed:
• Proposal submission
• System Simulations
• Circuit Schematic/Design
Future Goals:
• PCB Layout
• Qualification Report
• Performance Test
Timeline
Completed:
• Proposal submission
• System Simulations
• Circuit Schematic/Design
Future Goals:
• PCB Layout
• Qualification Report
• Performance Test
Budget
Questions?