1、Designation: F2840 11Standard Practice forDesign and Manufacture of Electric Propulsion Units forLight Sport Aircraft1This standard is issued under the fixed designation F2840; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the ye
2、ar of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers minimum requirements for thedesign and manufacture of Electric Propulsion Units (EPU)
3、forlight sport aircraft, VFR use. The EPU shall as a minimumconsist of the electric motor, associated controllers, discon-nects and wiring, an Energy Storage Device (ESD) such as abattery or capacitor, or both, and EPU monitoring gauges andmeters. Optional onboard charging devices, in-flight chargin
4、gdevices or other technology may be included.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regula
5、tory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2F2245 Specification for Design and Performance of a LightSport AirplaneF2279 Practice for QualityAssurance in the Manufacture ofFixed Wing Light Sport Aircraft2.2 Other Standards:EASA CRI F-58 Lithium Battery Installations3SAE
6、J2344 Guidelines for Electric Vehicle Safety43. Significance and Use3.1 This specification provides designers and manufacturersof electric propulsion for light sport aircraft design referencesand criteria to use in designing and manufacturing EPUs.3.2 Declaration of compliance is based on testing an
7、ddocumentation during the design, ground testing and flighttesting of the EPU by the manufacturer or under the manufac-turers guidance.3.3 Manufacturers of the EPUs are encouraged to reviewand incorporate appropriate standards and lessons learned fromground based systems as documented in SAE J2344 a
8、nd EASACRI F-58 (see Appendix X2).3.4 Electric aircraft may contain potentially hazardous levelof electrical voltage or current. It is important to protectpersons from exposure to this hazard. Under normal operatingconditions, adequate electrical isolation is achieved throughphysical separation mean
9、s such as the use of insulated wire,enclosures, or other barriers to direct contact. There areconditions or events that can occur outside normal operationthat can cause this protection to be degraded. Some meansshould be provided to detect degraded isolation or ground fault.In addition, processes or
10、 hardware, or both, should be providedto allow for controlled access to the high voltage system formaintenance or repair. A number of alternative means may beused to achieve these electrical safety goals including auto-matic hazardous voltage disconnects, manual disconnects,interlock systems, specia
11、l tools and grounding. The intention ofall these means is either to prevent inadvertent contact withhazardous voltages or to prevent damage or injury from theuncontrolled release of electric energy. Lightning strikes arenot addressed in this Standard Practice because LSA aircraftare limited to VMC f
12、light only.4. Electric Propulsion Unit (EPU) Model Designation4.1 Electric Propulsion Parts ListA detailed parts list isrequired for each electric propulsion unit qualified in accor-dance with this specification.4.2 New Electric Propulsion Unit Model Designations:4.2.1 Each new EPU must be qualified
13、 in accordance withthis practice.4.2.2 Design or configuration changes that impact the in-stallation interface, performance, or operability of the EPUrequire a new EPU model designation.1This practice is under the jurisdiction of ASTM Committee F37 on Light SportAircraft and is the direct responsibi
14、lity of Subcommittee F37.20 on Airplane.Current edition approved March 1, 2011. Published April 2011. DOI: 10.1520/F2840-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, r
15、efer to the standards Document Summary page onthe ASTM website.3Available from European Aviation Safety Agency (EASA), Postfach 10 12 53,D-50452 Koeln, Germany, http:/easa.europa.eu/home.php.4Available from SAE International (SAE), 400 Commonwealth Dr., Warrendale,PA 15096-0001, http:/www.sae.org.1C
16、opyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.3 Design Changes of PartsEach design change of a partor component of an EPU model qualified to this specificationshall be evaluated to the requirements of this specification.5. Data Req
17、uirements5.1 Retained DataThe following data and informationshall be retained on file at the manufacturers facility oralternative business entity for a minimum of 18 years afterproduction is discontinued.5.1.1 Drawings, reference specifications and other technicaldata that define the EPU configurati
18、on.5.1.2 Primary material and process (M energy storage devices(ESD); light sport aircraft (LSA)F2840 114APPENDIXES(Nonmandatory Information)X1. ELECTRIC PROPULSION TECHNOLOGY CONCEPTSX1.1 Electric Aircraft (EA)An aircraft that uses one ormore electric motors for propulsion. Depending on the type of
19、aircraft, motion may be by propellers, driven by a ducted fan,or any other means of converting electricity to propulsion.X1.2 Electric Propulsion Unit (EPU)Any electric motorand all associated devices used to provide thrust for an electricaircraft.X1.3 Energy Storage Device (ESD)Any manner thatstore
20、s some form of energy that can be drawn upon at a latertime to perform some useful operation. Typical energy storagedevices include but are not limited to: batteries, fuel cells orcapacitors.X1.4 In-flight Electrical Emergency (IEE)Any emer-gency caused by a malfunction or damage to the EPU or ESD.X
21、1.5 Brushless DC MotorA synchronous electric motorwhich is powered by direct current electricity and which has anelectronically controlled commutation system, instead of amechanical commutation system based on brushes. In suchmotors, current and torque, voltage and rpm are linearlyrelated.X1.6 Brush
22、ed DC MotorAn internally commutated elec-tric motor designed to be run from a DC power source.X1.7 Lithium-Polymer BatteriesLithium-ion polymerbatteries, polymer lithium ion or more commonly lithiumpolymer rechargeable batteries which have technologicallyevolved from lithium ion batteries. Typically
23、 a lithium-saltelectrolyte is held in a solid polymer composite such aspolyethylene oxide or polyacrylonitrile, although different cellchemistries are possible. Lithium polymer batteries have veryhigh energy densities.X1.8 Motor ControllerA device or devices that serves togovern the performance of a
24、n electric motor. It could include amanual or automatic means for starting or stopping the motor,selecting direction of rotation, selecting and regulating motorspeeds, regulating or limiting the torque and protecting againstoverloads and faults.X1.9 BatteryA device composed of electrochemical cellsu
25、sed to convert chemical energy to electrical energy.X1.10 CapacitorsA passive electrical device consistingof a pair of conductors separated by a dielectric (insulator).When a potential difference (voltage) exists across the conduc-tors, an electric field is present in the dielectric. This fieldstore
26、s energy.X1.11 IsolationThe electrical resistance between the bat-tery high voltage system and any airframe conductivestructure.X2. ADVANCED TECHNOLOGY BATTERIESINTRODUCTIONSeveral industry and governmental agencies have developed technical guidelines regarding the useof advanced technology batterie
27、s in both ground and air vehicles. In the United States, the Society ofAutomotive Engineers (SAE) has issued SAE J2344, covering ground vehicles. The reader isencouraged to review this document for reference. In Europe, EASA (European Aviation SafetyAgency) has identified in its document EASACRI F-5
28、8 a number of best practices deemed appropriatefor the inclusion of advanced technology batteries (ATB) for use in manned electric aircraft. Asynopsis of EASA CRI F-58 follows:X2.1 OverchargingLi batteries in general are signifi-cantly more susceptible to internal failures that can result inself-sus
29、tained increases in temperature and pressure (that is,thermal runaway) than their Ni-Cd and lead acid counterparts.This is especially true for over charging which causes heatingand destabilization of the components of the cell which cancause the formation of highly unstable metallic lithium whichcan
30、 ignite resulting in a self-sustaining fire or explosion.Certain types of Li batteries pose a potential safety problembecause of the instability and flammability of the organicelectrolyte employed by the cell of some Li battery types. Theseverity of thermal runaways increases with increasing battery
31、capacity, due to the high amount of electrolyte in largerbatteries. Therefore the ground charging of lithiumATB shouldbe approached with the same care, concern, and safety as thegasoline or jet fueling of aircraft.X2.2 Over Discharging:X2.2.1 Discharge of some versions of the Li cell beyond acertain
32、 voltage can cause corrosion of the electrodes of the cellresulting in loss of battery capacity that cannot be reversed byrecharging. This loss of capacity may not be detected by theF2840 115simple voltage measurements commonly available to flightcrews as a means of checking battery status, a proble
33、m sharedwith Ni-Cd batteries.X2.2.2 Safe cell temperatures and pressures must be main-tained during any probable charging or discharging condition,or during any failure of the charging or battery monitoringsystem not shown to be extremely remote. The lithium batteryinstallation must be designed to p
34、reclude explosion in the eventof those failures. Lithium batteries must be designed topreclude the occurrence of self sustaining uncontrolled in-creases in temperature or pressure. No explosive or toxicgasses emitted by any lithium battery in normal operation or asthe result of any failure of the ba
35、ttery charging or monitoringsystem, or battery installation not shown to be extremelyremote, may accumulate in hazardous quantities within theairplane. No corrosive fluids or gasses that may escape fromany lithium battery may damage surrounding airplane struc-tures or adjacent essential equipment. E
36、ach lithium batteryinstallation must have provisions to prevent any hazardouseffect on the structure or essential systems that may be causedby the maximum amount of heat the battery can generateduring a short circuit of the battery or of its individual cells.Lithium battery installations must have a
37、 system to control thecharging rate of the battery automatically so as to preventbattery overheating or overcharging. A battery temperaturesensing and over-temperature warning system with a means forautomatically disconnecting the battery from its chargingsource in the event of an over-temperature c
38、ondition should beincluded. A battery failure sensing system and warning systemwith a means for automatically disconnecting the battery fromits charging source in the event of battery failure should beincluded in the EPU design. A lithium battery installationwhose function is required for safe opera
39、tion of the airplane,must incorporate a monitoring and warning feature that willprovide an indication to the appropriate flight crew members,whenever the capacity and state of charge (SOC) of thebatteries have fallen below levels considered acceptable forflight. The operational manual for the ESD (l
40、ithium ATBs)must contain procedures for lithium batteries in spares storageto prevent replacement of batteries whose function is requiredfor safe flight, with batteries that have experienced degradedcharge retention or other damage due to prolonged storage atlow SOC.X2.3 Flammability of Cell Compone
41、nts:X2.3.1 Unlike Ni-Cd and lead acid cells, some types oflithium cells employ, in a liquid state, electrolytes that areknown to be flammable. This material can serve as a source offuel for an external fire in the event of a breach of the cellcontainer. In comparison to the flammability of conventio
42、nalfuels such as gasoline or jet fuel, this characteristic of lithiumbatteries should not be overly alarming except to say thatvigilance should be maintained in the use of ATBs to guardagainst fire hazard complacency.X2.3.2 It is envisaged that the core science of ATBs willcontinue to evolve in the
43、future, and that the Committees workwill evolve with the science, that tailoring of requirements maybe made such that more elegant and robust EPU and ESDdesigns can flourish. It is the intent that the work of thisCommittee not only establish technical order by the issuance ofspecifications, but also
44、 to advance the aeronautical sciences.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the r
45、iskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of t
46、his standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmak
47、e your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).F2840 116
