FUTURE AIRCRAFT

Future Aircraft Power Systems- Integration
Challenges
Outline
• Aircraft Electric Power Systems
– Existing Systems
– More-Electric-Airplanes (MEA)
• 787 No Bleed System
• Power Electronics
• Vision and Goals for Next Generation Electric
Airplane (NGEA)
• Role of Power Electronics and System
Simulation in NGEA
• Conclusions and Summary

777 Electrical System
“Traditional” Hybrid – 115Vac & 28Vdc
• Power Sources:
– Two - 120 kVA, 115Vac, 400Hz engine driven generators
– One 120 kVA, 115Vac, 400Hz Auxiliary Power Unit (APU) driven
generator
– Four 950 W Permanent Magnet Generators (PMG) integrated into the
two backup generators
– One 7.5kVA Ram Air Turbine (RAT)
– Main, APU, and flight controls batteries
• Conversion Equipment:
– Four 120 Amp DC Transformer Rectifier Units (115Vac to 28Vdc)
– Battery chargers and inverters
• Distribution System:
– Centralized distribution panels
– Thermal circuit breakers and electro-mechanical relays
– Contactors with built-in current sensing and control electronics

More-Electric-Airplane
Vision:
The More-Electric-Airplane has the potential to take
advantage of emerging technologies in power
generation and distribution, power electronics, and
energy storage.


Goals
• Improve power system efficiency
• Improve Weight/Volume
• Reduce Total Cost
• Enhance Safety
• Improve Thermal Efficiency
• Improve Reliability
• Improve Maintainability
• Increase Functionality
• Cost Effective Rapid Technological Insertion
• Green SystemsSystems

The Challenge
How can we most effectively minimize aviation’s 
impact on the environment – specifically CO2
emissions?

Future Aircraft Power Systems
– Advance Architectures
– Higher Voltage Systems
– High Temperature Power Electronics
– Adaptive and Intelligent power systems
– Power Electronics Integration
– Fuel CeSystemsSystems


More-Electric-Airplane Challenges
• Integration of New Power Electronics Loads
– System Power Quality
• All electrical loads are prone to failures when exposed to
one or more electrical power quality problems.
• Electrical equipment is only guaranteed/qualified to
operate properly if its input power quality is per
specification
• Examples:
– Interactions between power electronics loads and sources
(stability and resonance)
– Harmonic distortion
– Start-up
– Testing and Simulation is extensively used to
develop requirements, validate requirements, and
verify design

Simulation
• Models are developed using Multiple Tools• Challenges:
– Number of components
– Multiple Time Scales
– Different types of analysis (stability, power quality,
protection coordination, faults/failures, load
management)
– MoSystemsSystems

Conclusions
• More-Electric-Airplanes are the industry trend
• MEA is an enabler for advances in future airplane system
design, operation and performance
• MEA is a technology enabler for energy generation,
storage and conversion systems and technologies
• MEA contributes to lower operating costs and reduces
fuel use, emissions and noise.
• Power Electronics, Intelligent Power Systems, and
alternative sources play a significant role for future More-
Electric-Airplanes
• There remains challenges with efficient large-scale
simulation of more-electric-airplanes.