AEROSPACE ELECTRICAL SYSTEMS PAST, PRESENT, AND NEXT STEPS ERIC J. KLINE Engineering Manager Generators & Ram Air Turbines November 28-30, 2016
1 PAST: A BRIEF HISTORY OF ELECTRICAL SYSTEMS 2 Safran Electrical & Power / Confidential / November 2016 / Overview
AIRCRAFT ELECTRICAL POWER SYSTEMS BY ERA 1903 to 1913 No electrical power (0 V DC ) 1913 to 1920 Battery only (6-12 V DC ) 1920 to 1933 External Generators and Battery (12-24 V DC ) 1933 to 1945 Internal Generators and Battery (28 V DC ) 1945 to 1960 400 Hz AC, slip ring exciters (120 V AC, 400 Hz) 1960 to 1976 CSD, Rotor diodes brushless (120 V AC, 400 Hz) 1976 to 1996 IDG 400 Hz AC systems (120 V AC, 400 Hz) 1996 to today CF, VF, VSCF (120 V AC, 360-800 Hz) 1903 1927 1945 1970 2005
HISTORY OF AIRCRAFT ELECTRIC POWER: 1903-1913 1903: Wright Flyer first flight Early aircraft had no electric power on board No lights, no radio, no entertainment system Engines did not require electric power; magnetos for spark ignition Control surfaces entirely mechanical Flights lasted seconds to minutes and were dangerous
HISTORY OF AIRCRAFT ELECTRIC POWER: 1913-1920 Aircraft began to require electricity for radios and lights 1913: first use of wireless telegraphy (morse code) 1915: first use of 2-way voice communication 1916: Marconi Radio Company started production of ground-to-air radio transmitter/receivers 6-12V DC power provided by batteries (charged on ground) Battery charge would last length of flight Technology advancement driven by WW I
HISTORY OF AIRCRAFT ELECTRIC POWER: 1920-1933 Innovations increase electrical load Battery ignition for engines, radios, lights Flights get longer, required generator to re-charge battery 12-24 V DC Technology fueled by inter-war air transport growth (tourism and air mail)
HISTORY OF AIRCRAFT ELECTRIC POWER: 1920-1933 1921: US Army Air Corps bombing demo of USS Alabama.
HISTORY OF AIRCRAFT ELECTRIC POWER: 1920-1933 1921: Ram Air Turbine (RAT) generator on MB-2
HISTORY OF AIRCRAFT ELECTRIC POWER: 1920-1933 1921: RAT generator on Handley-Page W8B
HISTORY OF AIRCRAFT EL ECTRIC POWER: 1920-1933 1927: RAT generator on OX-5 Swallow
HISTORY OF AIRCRAFT EL ECTRIC POWER: 1920-1933 1930: RAT generators Handley-Page HP40
HISTORY OF AIRCRAFT ELECTRIC POWER: 1933-1945 Engine-mounted generators Electric starters Aerial Radar Required 600V power Used Motor-Generator sets to provide high-voltage Technology fueled by WW II 24-28 V DC batteries 120V AC : B-29 drives major changes to electrical system Douglas DC-1 B-17 Transcontinental capability More electric actuators, higher power levels, longer cable runs Need for high voltage to reduce current requirements 3-phase, 120V, 400Hz AC architecture chosen as optimum
HISTORY OF AIRCRAFT ELECTRIC POWER: 1933-1945 Converts 28 V DC to 600 V DC to drive radar loads Two machines built on one common shaft Lots of added weight just to convert voltage Douglas DC-1 B-17
HISTORY OF AIRCRAFT ELECTRIC POWER: 1933-1945 1945: B-29. First AC electrical system. Set standards still widely in use today. 3-phase, 120V, 400Hz AC 28 V DC for some loads Motor-gen set for high voltage radar load
HISTORY OF AIRCRAFT ELECTRIC POWER: 1945-1960 Innovations: 120V 3-phase AC implementation in large aircraft Sundstrand Constant Speed Drive (CSD) Technology driven by jet propulsion and Cold War Larger aircraft have two power busses: 28 VDC and 120V, 400 Hz AC constant frequency Mag-Amp and Carbon Pile voltage regulation B-29 and B-36
HISTORY OF AIRCRAFT ELECTRIC POWER: 1945-1960 Boeing 707 B-47
HISTORY OF AIRCRAFT ELECTRIC POWER: 1960-1975 Innovations: oil cooling, hermetic semiconductors, HiperCo50, Kapton, Nomex Diodes allow first brushless machines with rotating rectifiers Rotating exciters create AC power that is rectified to excite main rotor stage Previosly, slip rings were used to excite main rotor stage First oil-spray cooled machines 2-3x increase in power density Technology is driven by the space race and Cold War - miniaturization Analog generator control units and voltage regulators Concord DC-10 F-111 KC-135
HISTORY OF AIRCRAFT ELECTRIC POWER: 1975-1996 Business dominated by Sundstrand (later United Technologies) due to CSD (constant speed drive) 4-pole, 2-pole IDG s Analog GCUs common First digital GCUs (generator control units) Some competition from VSCF for 400 Hz Westinghouse did initial 737 power system (late-1960s) with VSCF (variable speed, constant frequency) Relied on power electronics, but maturity level was not sufficient Boeing eventually replaced with Sundstrand CSD and CF (constant frequency) generators 757 C-17 757
HISTORY OF AIRCRAFT ELECTRIC POWER: 1996-2016+ Rise of variable frequency (VF) systems: 360-800 Hz Diminishes monopoly of Hamilton-Sundstrand (United Technologies) Re-introduction of VSCF: more capable power electronics High voltage DC on military aircraft: 270V DC Still safety concerns on commercial aircraft, due to fault detection Brushless starter generator (BSG): commutation by power electronics instead of brushes VF systems: Global Express A380 787
MORE ELECTRIC AIRCRAFT: 2011+ Electric Start 100+ kva brushless starter-generators for engine start and power generation Replaces pneumatic start from APU; ducting is heavy, bulky, and difficult to maintain Ventilation Engine bleed air replaced with electric blowers and compressors Increases efficiency and thrust of engines Can be reduced during takeoff an REDUCED WEIGHT, INCREASED EFFICIENCY Actuation: gradual replacement of hydraulic equipment ETRAS: Electric Thrust Reverser Actuation System Electric-Mechanical and Electro-Hydraulic actuators Green Taxi APU powers motor on main landing gear wheels. 3% saving on total fuel burn; significant reduction in NOx, noise, and engine wear Electric Drive Train Helicoptor tail rotors, distributed propulsion for VTOL
2 SAFRAN AT A GLANCE 22 Safran Electrical & Power / Confidential / November 2016 / Overview
SAFRAN AT A GLANCE AN INTERNATIONAL HIGH-TECHNOLOGY GROUP 17.4 BILLION in sales* 2.4 BILLION in adjusted recurring operating income* 2.1 BILLION in R&D expenditures*, equal to nearly 12% of sales Over 900 INITIAL PATENTS filed in 2015 *2015 23 Safran Electrical & Power / Confidential / November 2016 / Overview
SAFRAN CAPABILITIES FOR ELECTRIC PROPULSION Electrical & Power Systems Formed in 2013 to address growing focus on aircraft electrification Distribution, Generation, Starters, Motors, Wiring Systems, System Development Includes former divisions of Goodrich, Lucas, Lear-Siegler, Jack & Heintz Aircraft Engines (formerly Snecma) Includes CFM JV with General Electric CFM-56, LEAP, Silvercrest, components for GE90 Helicopter Engines (formerly Turbomeca) Power Units (formerly Microturbo APUs) Transmissions (formerly Hispano-Suiza) 24 Safran Electrical & Power / Confidential / November 2016 / Overview
SAFRAN ELECTRICAL & POWER 25 COPPER Bird electrical system test facility. Safran Electrical & Power / Confidential / November 2016 / Overview
SAFRAN ELECTRICAL & POWER AT A GLANCE A WORLD LEADER IN ELECTRICAL SYSTEMS A WORLDWIDE CUSTOMER SERVICES NETWORK N 2 WORLDWIDE FOR ELECTRICAL power generation N 1 WORLDWIDE FOR EWIS* and ventilation systems ~ 14, 000 PEOPLE IN 12 COUNTRIES GLOBAL ENGINEERING SERVICES and innovative data & power interconnection systems Comprehensive product portfolio covering all on board electrical systems *EWIS: Electrical Wiring Interconnection Systems (2015 figures) 26 Safran Electrical & Power / Confidential / November 2016 / Overview
AN UNRIVALLED PRODUCT RANGE GENERATION > Variable and constant frequency AC generators > 2-Pole, high speed APU generators > 28VDC Brush and Brushless DC Start Generators DISTRIBUTION > AC and DC distribution > Secondary AC and DC Solid State Power Controller (SSPC) > Circuit breakers > Contactors & Relays ALTERNATE POWER > Auxiliary Power Unit e-apu and MPG (Main Power Generators) > RAT (Ram Air Turbine) product policy from conventional deploy to integrated solutions WIRING > EWIS processes and Tools > All-ATA interface modeling & simulation > One-Stop Shop for configuration control LOADS ELECTRIFICATION > Green Taxiing (APU Supplied) and e-brake > Electric Nacelle (etras- Electrical Thrust Reverser Actuation System, VFN - Variable Fan Nozzle, Anti- Ice functions) > Electric Engine Start > Flight Controls EMA (Electro Mechanical Actuator) INTEGRATION & CERTIFICATION > Complete nose-to-tail electrical power systems for any size of aircraft > Integration of a complete electrical power generation and distribution system and certification process support > Variable frequency fans 27 Safran Electrical & Power / Confidential / November 2016 / Overview
Day/month/year SAFRAN AIRCRAFT ENGINES 28 Safran Electrical & Power / Confidential / November 2016 / Overview
CFM No. 1 engine supplier worldwide for mainline commercial jets (over 100 seats) More than 550 customers worldwide Safran Aircraft Engines & GE, successful partners for over 40 years 50/50 joint company All activities are equally split: design, development, production, sales and support. Partnership extended to 2040 29 Safran Electrical & Power / Confidential / November 2016 / Overview
CFM56, LEAP Combining the best technologies from Safran Aircraft Engines and GE A320 A320NEO A330 More than 29,000 CFM56 engines delivered worldwide B737MAX B777 B737 C929 A380 More than 10,000 engines ordered to date CFM56-5B CFM56-7B Over 29,000 sold. LEAP-1A LEAP-1B LEAP-1C 15% reduction in CO 2 emissions CFM-6 GE90 GP7200 GE s main partner for large turbofans. GE90 The most powerful aero-engine in the world 30 Safran Electrical & Power / Confidential / November 2016 / Overview
Day/month/year SAFRAN HELICOPTER ENGINES Turboshaft engines Helicoptor and VTOL applications 31 Safran Electrical & Power / Confidential / November 2016 / Overview
Day/month/year SAFRAN TRANSMISSION SYSTEMS: A WORLD LEADER IN MECHANICAL POWER TRANSMISSION SYSTEMS 32 Safran Electrical & Power / Confidential / November 2016 / Overview
3 NEXT STEPS, STANDARDS, AND CERTIFICATION 33 Safran Electrical & Power / Confidential / November 2016 / Overview
ELECTRIC PROPULSION ARCHITECTURES Series Parallel All-Electric Battery powered (low energy density limits applications to short flights, unmanned vehicles) Electricity provided by fuel cell; fuel cell TRL (technology readiness level) not currently sufficient. Turbo-Electric Engine powered generator provides electric power to motorized propellers Distributed propulsion where multiple engines are not practical (i.e. X-57 or VTOL applications) Electric Drive Train Some portion of propulsion provided directly by engine Distributed propulsion powered via electrical drive train i.e. Helicoptor tail rotor 34 Safran Electrical & Power / Confidential / November 2016 / Overview
STANDARDS, BEST PRACTICES, SAFETY Power Quality Standards Exist to simplify system integration for airframers But also dumb down envelope based on sometimes outdated limitations New standards will be needed for advanced electrical systems Best Practices for Aerospace Design: SAE ARP4754A Safety: SAE ARP4761 Allowable catastrophic failure probability for a system: 10-9 /flight hr 737 fleet hrs = 13,000 aircraft x 80,000 hr = 10 9 flight hrs So a single system can never demonstrate high enough reliability Plan for redundancy if you hope to certify Why do RATs exist? Because there are common fault modes for electrical system: i.e. fuel Gimli Glider 1982: 767 ran out of fuel. Glided 100+ miles using 20kW of RAT power for control. 18 incidents of RAT deployment for emergency use in past 30 years 35 Safran Electrical & Power / Confidential / November 2016 / Overview
MODERN RAM AIR TURBINE Uses power in airstream to generate electrical or hydraulic power Constant rotational speed via centrifugal governor Power independent of main electrical or hydraulic system Power independent of fuel system 36 Safran Electrical & Power / Confidential / November 2016 / Overview
Thank you! 37 Safran Electrical & Power / Confidential / November 2016 / Overview