Date post: | 07-Apr-2018 |
Category: |
Documents |
Upload: | grahamtown |
View: | 219 times |
Download: | 0 times |
8/6/2019 Town Power Management
http://slidepdf.com/reader/full/town-power-management 1/19
1
POWER MANAGEMENTPOWER MANAGEMENT
FORFORSUSTAINABLE ENERGY SYSTEMSSUSTAINABLE ENERGY SYSTEMS
Graham Town
Electronic Engineering
Macquarie University.
8/6/2019 Town Power Management
http://slidepdf.com/reader/full/town-power-management 2/19
2
OVERVIEWOVERVIEW• The need for
– decreasing reliance on fossil fuels
– increased reliance on sustainable sources of energy
– efficiency in energy conversion and use
• Sustainable energy systems
– source, storage, load, power management…
• Efficiency in sustainable energy systems
– solar cells, wind turbines, batteries, converters
• Integrated circuits for
– power conversion & management
– energy harvesting
8/6/2019 Town Power Management
http://slidepdf.com/reader/full/town-power-management 3/19
3
ENERGY 2010ENERGY 2010• Fossil fuels (oil, coal) are main source of energy in modern society.
• Advantages: high energy density (45MJ/kg, approx. twice ethanol)
relatively easy to transport safely, easy to use.
8/6/2019 Town Power Management
http://slidepdf.com/reader/full/town-power-management 4/19
4
ENERGY 2010ENERGY 2010• CO2 emissions are mainly from burning fossil fuels for:
– Electricity generation (coal)
– Transport (oil)
8/6/2019 Town Power Management
http://slidepdf.com/reader/full/town-power-management 6/19
6
PROBLEMS WITH FOSSIL FUELSPROBLEMS WITH FOSSIL FUELS2. CO2 emissions causing environmental change
– Global warming caused by greenhouse gases in atmosphere climate change, extreme weather events, etc.
– Ocean acidification caused by absorption of CO2
potential threat to marine food chain
8/6/2019 Town Power Management
http://slidepdf.com/reader/full/town-power-management 7/19
7
ENERGY OPTIONS TO 2050+ENERGY OPTIONS TO 2050+1. Reduce fossil fuel usage
i) for the environment, ii) to make resource last longer
To use less energy (esp. for transport, heating/cooling)….• reduce population and/or living standards
increase energy efficiency
Campbell, “Petroleum and People”,
Pop’n and Environ.,24 , 193 (2002).
8/6/2019 Town Power Management
http://slidepdf.com/reader/full/town-power-management 8/19
8
ENERGY OPTIONS TO 2050+ENERGY OPTIONS TO 2050+2. Replace fossil fuels with sustainable energy sources (i.e. no
compromise to the needs of future generations)
– Nuclear energy – “Renewable” (naturally replenished) sources of “green” (unpolluting)
energy
• solar
• wind
• wave & tidal
• hydropower
• biomass
• geothermal
– Energy harvesting
International Energy Agency, “KeyWorld Energy Statistics,” p6 (2009).
8/6/2019 Town Power Management
http://slidepdf.com/reader/full/town-power-management 9/19
9
PRACTICAL ENERGY MATTERSPRACTICAL ENERGY MATTERS• Available on demand?
• e.g. solar power not available at night, wind power often variable
• Storage? (if not available on demand)• e.g. thermal, mechanical, chemical, electrical
• Transport? (if source and load not colocated)
• e.g. electrical, chemical
• Efficient conversion (for storage, transport)• e.g. chemical electrical (e.g. battery)• e.g. thermal mechanical (e.g. steam turbine)
• e.g. mechanical electrical (e.g. wind turbine)• e.g. electrical electrical (e.g. DC-AC, DC-DC converters ~95% efficient)• conversion efficiency particularly important for harvesting small amounts of
energy from the environment (ambient light, vibrations) for mobile devices.
8/6/2019 Town Power Management
http://slidepdf.com/reader/full/town-power-management 10/19
10
POWER SYSTEM MANAGEMENTPOWER SYSTEM MANAGEMENT• Any electric power system has a source, load, and usually storage
• Each of the components have a preferred operating point
– e.g. maximum power point (V and I for max. power transfer) – e.g. charge/discharge rate for max. lifetime
• Power management is req’d to maximise system performance,especially in energy harvesting (ambient sources: small, variable)
8/6/2019 Town Power Management
http://slidepdf.com/reader/full/town-power-management 11/19
11
SOLAR CELL ARRAYSOLAR CELL ARRAYCHARACTERISTICSCHARACTERISTICS
• For a given irradiance, the power extracted from a solar cell (oruniform array) depends on the voltage across it, up to a maximum – the maximum power point, or MPP
http://www.innovativesolar.com/images/File/BSE_What_is_MPPT.pdf
8/6/2019 Town Power Management
http://slidepdf.com/reader/full/town-power-management 12/19
12
SOLAR CELL ARRAYSOLAR CELL ARRAYCHARACTERISTICSCHARACTERISTICS
• The MPP varies with irradiance, temperature, etc.
• Arrays of cells are often used to boost voltage or current – BUT shadowing of any cells in array can cause large reduction in avail. power
• Need smart and efficient power conversion & combining
Organic (polymer) solar cell array fabricated and characterised by the author at St Andrews University (2009)
8/6/2019 Town Power Management
http://slidepdf.com/reader/full/town-power-management 13/19
13
ENERGY STORAGE TECHNOLOGYENERGY STORAGE TECHNOLOGY• Many different technologies available, different characteristics
http://www.mpoweruk.com/performance.htm
http://www.batteryuniversity.com/parttwo-34.htm
Longevity
of lithium-
ion as a
function of
charge and
discharge
rates.
A moderate charge and discharge
puts less
stress on
the battery,
resulting in
a longer
cycle life.
8/6/2019 Town Power Management
http://slidepdf.com/reader/full/town-power-management 14/19
14
GREEN TRANSPORTGREEN TRANSPORTThis?
……….. or this?
http://www.gizmag.com/lexus-hybrid-bicycle-concept/14938/
8/6/2019 Town Power Management
http://slidepdf.com/reader/full/town-power-management 15/19
15
GREEN TRANSPORTGREEN TRANSPORT
http://www.gizmag.com/lexus-hybrid-bicycle-concept/14938/
8/6/2019 Town Power Management
http://slidepdf.com/reader/full/town-power-management 16/19
16
ENERGY HARVESTINGENERGY HARVESTING• e.g. “wireless switch” technology
The effort made in pushing the switch powers a small and efficient wireless
transmission system to activate remote equipment• e.g. power generators in your shoes
The act of walking generates electricity by flexing a piezoelectric materialembedded in a shoe, e.g. to charge a battery for mobile communication, etc.
https://reader009.{domain}/reader009/html5/0515/5afa17f0248c2/5afa17f82a975.jpg
8/6/2019 Town Power Management
http://slidepdf.com/reader/full/town-power-management 17/19
17
POWER TECHNOLOGYPOWER TECHNOLOGY• Will follow same evolutionary path as wireless communication
technology (i.e. to smaller, more mobile systems)
8/6/2019 Town Power Management
http://slidepdf.com/reader/full/town-power-management 18/19
18
““POWER SUPPLY ON A CHIPPOWER SUPPLY ON A CHIP””• Research sponsored by local company, Sapphicon Semiconductor
– Only IC manufacturer in Australia
– Silicon-on-sapphire CMOS platform• Transparent sapphire substrate low loss, high speed, efficient heat x’fer
• Better than standard CMOS for power management and energy harvesting
8/6/2019 Town Power Management
http://slidepdf.com/reader/full/town-power-management 19/19
19
CONCLUSIONSCONCLUSIONS• We need to change energy usage patterns
develop different sources of energy
use available energy more efficiently
• Integrated electronics provides reliable, low cost, and
compact technology for efficient energy conversion and utilisation
smart management of power systems…
and the battery on your mobile phone will last longer !