SAE AIR7502-2021 PDF

Full title and description

SAE AIR7502 — Aircraft Electrical Voltage Level Definitions. This SAE Aerospace Information Report defines standardized voltage-level names and recommended voltage ranges for current and future aircraft electrical architectures to support increasing electrification, hybrid-electric and electric propulsion applications.

Abstract

This information report documents agreed voltage-level definitions for aircraft electrical systems, provides rationale for selected levels and lists candidate supply voltages (for example 0–270 VDC, ±135 VDC, ±270 VDC, 0–540 VDC and higher) so industry stakeholders have a common vocabulary and baseline when designing, qualifying and certifying higher-voltage aircraft systems as electrification increases.

General information

• Status: Issued.
• Publication date: January 27, 2021.
• Publisher: SAE International.
• ICS / categories: Aircraft electrical systems; electric power; high-voltage systems; wiring and insulation; aerospace terminology.
• Edition / version: Original issue (AIR7502, 2021).
• Number of pages: 3 pages (information report length).

Scope

The report sets forth aircraft electrical voltage level definitions and provides the committee’s rationale for those levels. It is intended to establish consistent names and numeric ranges for nominal supply voltages used in conventional, more-electric, hybrid and electric aircraft programs so designers, integrators and certification authorities can reference a common baseline when addressing system architecture, safety and wiring design considerations.

Key topics and requirements

• Definitions of standardized voltage levels and naming conventions for aircraft DC and bipolar bus voltages (including candidate ranges such as 0–270 VDC, ±135 VDC, ±270 VDC and 0–540 VDC).
• Rationale for selecting particular voltage ranges in the context of power density, wiring mass, insulation and safety trade-offs.
• Guidance to help harmonize system-level discussions across OEMs, suppliers and regulatory stakeholders when specifying electrical architectures for electrified aircraft.
• Implications for wiring, insulation selection and EWIS design that follow from adopting higher nominal voltages (refer to companion reports addressing wiring impacts).

Typical use and users

Used by aerospace electrical systems engineers, power systems architects, EWIS designers, aircraft OEMs, suppliers of power electronics and wiring, certification engineers and standards committees to align terminology, select candidate supply voltages and evaluate system-level impacts as programs migrate to higher-voltage architectures.

Related standards

Companion and related documents include SAE AIR7506 (Impact of High Voltage on Wiring) which addresses wiring and insulation effects of increased system voltages; industry wiring and installation standards (for example AS50881 and related EWIS guidance) and other SAE ARPs and AIRs addressing high-voltage design, corona, insulation and certification considerations for electrified aircraft.

Keywords

Aircraft voltage levels, electrical architecture, high voltage, hybrid-electric aircraft, electrification, EWIS, insulation, voltage definitions, SAE AIR7502.

FAQ

Q: What is this standard?

A: SAE AIR7502 is an SAE Aerospace Information Report that defines standardized names and numeric ranges for aircraft electrical voltage levels to support common industry terminology and system design for more-electric and electrified aircraft programs.

Q: What does it cover?

A: It documents voltage-level definitions, gives the committee’s rationale for chosen ranges and lists candidate supply voltages used when evaluating higher-voltage aircraft electrical systems and propulsion concepts.

Q: Who typically uses it?

A: Aerospace electrical and systems engineers, EWIS designers, OEMs, suppliers of power electronics and wiring, certification engineers and standards committees use it as a reference for voltage-level terminology and initial architecture discussions.

Q: Is it current or superseded?

A: The original AIR7502 was issued January 27, 2021. Users should check SAE International for any revisions or amendments after 2021; companion reports and later revisions may expand or update guidance.

Q: Is it part of a series?

A: AIR7502 is part of SAE’s set of aerospace information reports addressing high-voltage and electrification topics (for example AIR7506 addressing wiring impacts); it complements other SAE ARPs/AIRs and industry EWIS standards that together support high-voltage aircraft system development.

Q: What are the key keywords?

A: Aircraft voltage levels, high voltage, electrified aircraft, EWIS, insulation, power architecture, SAE AIR7502.