ISO INTERNATIONAL STANDARD 1540 Third edition 2006-02-15 Aerospace Characteristics of aircraft electrical systems Aéronautique Caractéristiques des systemes électriques a bord des aeronefs Reference number ISO 1540:2006(E) @ISO2006 E"eqr[tkijvgf"d["WPG.'E1"1gpqxc."8I"4:226"Ocftkf.'Urckp*cm'tkijv "tgugtxgf+"Ygf"Hgd36*27<56<75*WVE*4246 ISO1540:2006(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The Iso Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by IsO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below @ISO2006 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, Iso's member body in the country of the requester ISO copyright office Case postale 56: CH-1211 Geneva 20 Tel.+ 4122 749 0111 Fax + 41 22 749 09 47 E-mail [email protected] Web www.iso.org Published in Switzerland ii Iso2006-All rights reserved E"eqr[tkijvgf"d["WPG.'E1"1gpqxc."8I"4:226"Ocftkf.'Urckp*cm'tkijvu'tgugtxgf+*"Ygf"Hgd’36*27<56<75"WVE"4246 knnitrawintiInfi ISO 1540:2006(E) Contents Page Foreword.. iv Introduction .. V 1 Scope 2 Normative references.. 3 Terms and definitions.. 4 Requirements applicable to all systems .... 10 4.1 4.2 On-aircraft power sources 4.3 External power sources .... 11 4.4 Source/distribution system coordination.... 11 4.5 Utilization equipment.... 11 5 Constant frequency (CF) a.c. power system characteristics 5.1 General characteristics . 12 5.2 Steady-state characteristics.. 13 5.3 Transient characteristics. 13 6 Variable frequency (VF) a.c. power system characteristics. 15 6.1 General characteristics..... 6.2 Consideration of CF power characteristics 15 6.3 Steady-state characteristics..... 15 6.4 Transient characteristics... 7 D.C. power system characteristics . 7.1 Generalcharacteristics 7.2 Steady-state characteristics 19 7.3 Transient characteristics . 20 8 Requirements allocation .. 21 9 Utilization equipment restrictions. 21 9.1 21 9.2 A.C. power utilization .. 21 9.3 Power factor ...... 21 9.4 Load switching transients 22 9.5 Inrush current.. 22 9.6 Input current modulation . 22 9.7 Input current distortion .. 22 9.8 Maximum input capacitance.. 10 Power quality associated assumptions and background 24 10.1 General. .24 10.2 Background to the document scope .... 25 10.3 A.C. power system assumptions ....... 25 10.4 A.C. source equipment assumptions 29 10.5 D.C. system assumptions .... 31 10.6 D.C. engine starting power quality.. 32 10.7 27o V d.. input power...... ii ISO 1540:2006(E) Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards bodies (isO member bodies). The work of preparing International Standards is normally carried out through IsO International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization International Standards are drafted in accordance with the rules given in the ISO/lEc Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. IsO shall not be held responsible for identifying any or all such patent rights. ISO 1540 was prepared by Technical Committee ISO/TC