This Aerospace Information Report presents an overview of the application and control of fixed and variable displacement pumps with the emphasis on the controls most commonly used on variable displacement pumps. It describes various options to control the operation of hydraulic pumps in terms of controlling the pump output pressure and/or flow and assisting in the selection of the pump.
This SAE Aerospace Standard (AS) establishes the minimum performance standards for an AC to AC converter power sources in aerospace electric power systems. AC to AC converters are designed and used as a subsystem to deliver various ac voltage levels within power distribution systems for general aviation applications, cockpit lighting and aircraft cabin interiors.
This SAE Standard specifies the ESD test methods and procedures necessary to evaluate electronic modules intended for vehicle use. It describes test procedures for evaluating electronic modules in complete vehicles. A procedure for verifying the simulator that is used to generate the electrostatic discharges is given in Appendix A. Functional status classifications for immunity to ESD are given in Appendix B.
Abstract Projected capacitive touchscreen (PCAP) became popular thanks to the introduction of the Apple iPhone, iPad and iPod. Electrical field generated for touch detection is known to be impaired by external fields, for example Cold Cathode Fluorescent Lamp, USB charger or AMLCD driving. Commercial product shall live with this issue, but the high intensity radiated field required for avionics application is several orders of magnitude higher than required for commercial product. In such an environment, standard touchscreens could have hazardous behavior. Thanks to the unique 20 years' experience on projected capacitive technology (Aircraft fighter), we designed a new projected capacitive touchscreen, based on a ruggedized touch controller and dedicated ASIC, able to operate in extreme electromagnetic environment.
This AIR is intended to provide basic guidance on the methodologies that should be utilized when contemplating the design and development of rechargeable lithium battery systems for utilization onboard aircraft. These guidelines will apply to “installed” equipment which would be part of the original or supplemental type certification or military airframe qualification.
This SAE Standard specifies the test methods and procedures for testing passenger cars and commercial vehicles to magnetic fields generated by power transmission lines and generating stations. SAE J551-1 specifies general information, definitions, practical use, and basic principles of the test procedure.
This document shall provide the fundamental safety considerations in pursuing the design of a 48/60 VDC aircraft electrical system. This departure from the current standard of 28 VDC will provide the benefits of reducing the operational weight and fuel consumption of the aircraft by increasing the DC system voltage level.
This SAE Aerospace Recommended Practice (ARP) provides guidance for the verification and certification of a “commercial” fixed wing aircraft fuel tank inerting system (FTIS) and will provide technical references and data regarding ground and flight testing of an FTIS. The intent of this ARP is to address issues associated with the verification requirements based on current regulatory guidance per AC25.981-2C
Measurement of Radiated Emissions from Integrated Circuits -- Surface Scan Method (Loop Probe Method) 10 MHz to 3 GHz
This SAE Recommended Practice defines a method for evaluating the near field electric or magnetic component of the electromagnetic field at the surface of an integrated circuit (IC). This technique is capable of providing a detailed pattern of the RF sources internal to the IC. The resolution of the pattern is determined by the characteristics of the probes used and the precision of the mechanical probe positioner. The method is usable over the 10 MHz to 3 GHz frequency range with existing probe technology. The probe is mechanically scanned according to a programmed pattern in a plane parallel or perpendicular to the IC surface and the data is computer processed to provide a color-enhanced representation of field strength at the scan frequency. This procedure is applicable to measurements from an IC mounted on any circuit board that is accessible to the scan probe. For comparisons, the standardized test board shall be used.
This SAE Aerospace Standard (AS) covers the general requirements for the design, manufacture, and test of Solid State Power Controllers (SSPCs) of both dc and ac ratings for use in electrical power systems. SSPCs conforming to this standard are intended for use in controlling the making and breaking of power circuits for electrically operated equipment and devices, and for providing overload and short-circuit protection.
Abstract Electromagnetic interference (EMI) is a common problem in power electronics systems. Pulse-width modulation (PWM) control of semiconductor devices in a power converter circuit creates discontinuity in voltage and current with rich harmonics over a broad frequency range, creating both conducted and radiated noise. The increase in switching speed enabled by new power semiconductor devices helps to reduce converter size and reduce switching losses, but further exacerbates the EMI problem. Complying with regulatory EMI emission limits requires the use of EMI filters in almost all power converter designs, and EMI filters are often the dominant elements for system volume, weight, and cost. Electromagnetic interference (EMI) filtering is a critical driver for volume and weight for many applications, particularly in airborne and other mobile platforms.
Abstract Electromagnetic compatibility (EMC) is becoming more important in power converters and motor drives as seen in hybrid electric vehicles (HEV) to achieve higher reliability of the vehicle and its components. Electromagnetic interference (EMI) of the electronic components for a vehicle are evaluated and validated at a component-level test bench; however, it is sometimes observed that the EMI level of the components can be changed in a vehicle-level test due to differences in the vehicle's configuration (cable routing, connecting location etc.). In this presentation, a vehicle-level EMC simulation methodology is introduced to estimate radiated emissions from a vehicle. The comparison between the simulation and measurement results is also presented and discussed.
Abstract Transportation systems use wireless technology to link vehicles and mobile devices to each other, and to the transportation infrastructure. This paper presents an advanced approach supporting and establishing a future testing and certification framework for vehicles and applications that can leverage wireless communications for the transportation environment. Assessing such integrated communication systems performance will realize the full potential of connected vehicles, travelers and infrastructure. To reach this potential, connected vehicle equipment and applications must meet minimum performance requirements, conform to common technical standards, and interoperate with one another. Over-The-Air Testing and Certification method provides formal means of verifying that a vehicle integrating specific communication technology fulfills the End-User's expectations and complies with Standards and Regulations.
Electromagnetic Compatibility Measurement Procedure for Vehicle Components - Part 13: Immunity to Electrostatic Discharge
This SAE Standard specifies the test methods and procedures necessary to evaluate electrical components intended for automotive use to the threat of Electrostatic Discharges (ESDs). It describes test procedures for evaluating electrical components on the bench in the powered mode and for the packaging and handling non-powered mode. A procedure for calibrating the simulator that is used for electrostatic discharges is given in Appendix A. An example of how to calculate the RC Time Constant is given in Appendix B. Functional Performance Status Classifications for immunity to ESD and Sensitivity classificatins for ESD sensitive devices are given in Appendix C.
The standard will apply to (but not necessarily be limited to) cables, line impedance stabilization networks, pre-amplifiers, attenuators, current probes, etc.
Performance Levels and Methods of Measurement of Electromagnetic Compatibility of Vehicles, Boats (up to 15 m), and Machines (16.6 Hz to 18 GHz)
This SAE Standard covers the measurement of radio frequency radiated emissions and immunity. Each part details the requirements for a specific type of electromagnetic compatibility (EMC) test and the applicable frequency range of the test method. The methods are applicable to a vehicle, boat, machine or device powered by an internal combustion engine or battery powered electric motor. Operation of all engines or motors (main and auxiliary) of a vehicle, boat, machine or device is included. All equipment normally operating when the vehicle, boat, machine or device is in operation is included. Operator controlled equipment is included or excluded as specified in the individual document parts. As a special case, CISPR 12 applies to battery powered floor finishing equipment, but robot carpet sweepers are excluded. By reference, IEC CISPR 12 and CISPR 25 are adopted as the standards for the measurement of vehicle emissions.
This specification covers constant displacement hydraulic motors, generally remotely mounted, using hydraulic fluid under pressure as the energy transfer medium for driving various accessories. Hydraulic motors shall be suitable for use in aircraft hydraulic systems conforming to and as defined in MIL-H-5440 and MIL-H-8891 as applicable.
Abstract This paper describes a high-speed electrical machine for an aircraft starter-generator. A surface mounted permanent magnet machine is designed to have minimal rotor losses and a novel cooling system for the stator. An inner stator sleeve is adopted to allow for a flooded stator whilst minimizing rotor windage losses. Different slot-pole combinations are compared in view of attaining an optimal combination that provides minimum losses whilst satisfying the electromagnetic, mechanical and thermal constraints.
Impact of Cable Bundles and Systems' Integration Rules Dedicated to Metallic Aircraft on the Electromagnetic Immunity of Systems in Composite Aircraft
Abstract Advanced commercial aircraft increasingly use more composite or hybrid (metal and composite) materials in structural elements and, despite technological challenges to be overcome, composites remain the future of the aviation industry. Composite and hybrid aircraft today are equipped with digital systems such as fly by wire for reliable operations no matter what the flying environment is. These systems are however very sensitive to electromagnetic energy. During flight, aircraft can face High Intensity Radiated Fields (HIRF), static electricity, or lightning. The coupling of any of these threats with airframe structure induces electromagnetic energy that can impair the operation of avionics and navigation systems. This paper focuses on systems susceptibility in composite aircraft and concludes that the same electromagnetic rules dedicated to all metal aircraft for systems and wiring integration cannot be applied directly as such for composite aircraft.
This AIR intends to better document and tabulate electrical load dynamics that influence power source capacity, power quality and stabiltiy.
This SAE Aerospace Recommended Practice (ARP) is an application guide for fixed and variable displacement hydraulic motors. It provides details of the characteristics of fixed and variable displacement hydraulic motors, architectures, circuit designs, controls, and typical applications. The applications include airborne and defense vehicles with emphasis on high performance applications.
This SAE Aerospace Standard (AS) establishes the minimum performance standards for equipment used as secondary alternating current (AC) electrical power sources in aerospace electric power systems.
This SAE Aerospace Recommended Practice (ARP) defines lightning strike zones and provides guidelines for locating them on particular aircraft, together with examples. The zone definitions and location guidelines described herein are applicable to Parts 23, 25, 27, and 29 aircraft. The zone location guidelines and examples are representative of in-flight lightning exposures.
SAE ARP to provide guidance and best practices for demonstrating civil aircraft electromagnetic compatibility (EMC). Incorporate EMC guidance for large transport airplanes, business airplanes, small airplanes, small helicopters, and transport helicopters. Provide guidance that considers compliance with aircraft safety requirements, and also considers intended performance of non-required and non-essential aircraft systems. Provide guidance on aircraft equipment EMC qualification, aircraft system and wiring installation, and aircraft EMC tests.
This SAE Standard defines a method for evaluating the immunity of automotive electrical/electronic devices to radiated electromagnetic fields coupled to the vehicle wiring harness. The method, called Bulk Current Injection (BCI), uses a current probe to inject RF onto the wiring harness in the frequency range of 1 to 400 MHz. BCI is one of a number of test methods that can be used to simulate the electromagnetic field.
This SAE Aerospace Recommended Practice (ARP) establishes software capability guidelines for computer controlled test equipment, hereinafter referred to as automatic test equipment (ATE), for testing hydraulic components. A typical ATE system is shown. The items herein have been selected as potential features which may or may not be applicable to a particular application. This document does not address software development requirements, qualification procedures, or hardware design requirements, but encourages users to refer to existing documents for guidance on such issues.
Electromagnetic Compatibility Measurement Procedure for Vehicle Components - Immunity to AC Power Line Electric Fields
This SAE Recommended Practice covers the recommended testing techniques for the determination of electric field immunity of an automotive electronic device when the device and its wiring harness is exposed to a power line electric field. This technique uses a parallel plate field generator and a high voltage, low current voltage source to produce the field.
Abstract There are certain products which ask for Isolation requirement to be met. To meet this requirement, we usually make use of Isolated DC - DC converter which is an easy & compact solution. Usually this leads to severe electromagnetic interference issues which badly impact the Certification/Qualification of the product. This is due to the in-built transformer in the Isolated DC - DC converter device, which switches at high frequency, in the range of mega hertz. Considerable amount of time and money is spent in debugging and resolving these issues. This paper is intended to address these issues with solutions, which will help the designer to take care at the Design stage, thereby saving time & money, the important parameters of the project cost. A set of experiments & analysis were conducted to find the root-cause of the issue.
In the sensitive automotive applications like the safety restraint systems (SRS), twisted lines can be used to link the components of the system because of their property of reduction of the electromagnetic interference (EMI) coupling. Compared to the parallel lines, the twisted lines present the drawback to consume more copper in their manufacturing due to the greater length of their conductors. A parametric study based on the numerical modeling and the measurement of twisted lines is conducted in order to analyze the effect of the twisting pitch and of the untwisted part of these lines on the level of EMI coupling. This study will enable to optimize these two parameters in order to reduce the level of EMI coupling as well as the length of the conductors of the lines.
Abstract This work presents a physical model that calculates the efficiency maps of the inverter-fed Permanent Magnet Synchronous Machine (PMSM) drive. The corresponding electrical machine and its controller are implemented based on the two-phase (d-q) equivalent circuits that take into account the copper loss as well as the iron loss of the PMSM. A control strategy that optimizes the machine efficiency is applied in the controller to maximize the possible output torque. In addition, the model applies an analytical method to predict the losses of the voltage source inverter. Consequently, the efficiency maps within the entire operating region of the PMSM drive can be derived from the simulation results, and they are used to represent electric drives in the system simulation model of electric vehicles (EVs).