Avionics

Avionics Power Standards Compliance Testing

Avionics power standards compliance testing, refers to a crucial process within the aviation industry. It refers to the evaluation and verification of power-related aspects of avionics systems to ensure their compliance with established standards and specifications. In an industry where safety and reliability are vital, this process plays a key role in ensuring the performance of avionics equipment, which in turn promotes the safe operation of aircraft.

Key Aspects of Compliance Testing for Avionics Power Standards

Voltage and Current Requirements

Testing avionics systems to verify that they operate within specified limits for voltage and current is essential. This covers not only normal operating conditions, but also sudden events and power fluctuations that may occur during aircraft operations.

Power supply stability

Ensuring that the power supply to avionics components remains stable and within acceptable tolerances under various conditions. This should take into account changes in load, temperature and environmental conditions.

Response to transient events

Assess how avionics systems respond to sudden changes in power supply, such as during engine start-up or shutdown. The aim is to ensure that they can handle these transient events without failure.

Power factor correction Checking compliance with power factor correction standards to improve energy use efficiency and minimise harmonic distortion in electrical systems.

EMI/RFI Emissions

Evaluating avionics equipment for electromagnetic interference (EMI) and radio frequency interference (RFI) emissions. This ensures that these emissions do not adversely affect other aircraft systems or communication frequencies.

Integrity of Power Distribution

Testing the integrity of the power distribution system to confirm that power is distributed evenly and reliably to all avionics components. Influence of Environmental Factors Consider the influence of environmental conditions, such as extreme temperatures, on the performance of avionics power systems.

Compliance with Specific Standards

Ensure that avionics power systems comply with relevant industry standards and regulations. This considers standards specified by organisations such as RTCA, SAE and others.

Power consumption

Assess the total power consumption of avionics systems to optimise energy use and support efficient aircraft operations.

The Test Process and Significant Role in Aviation

Compliance with power standards is a process performed in laboratory environments, often by manufacturers during the development and certification phases of avionics systems. These tests are not only crucial for initial certification but are also repeated regularly during routine maintenance to ensure compliance with power standards throughout the operational life of the aircraft. The process aims to ensure the safety and reliability of aircraft systems. Since power-related problems can have a significant impact on the performance of avionics equipment, and therefore flight safety, compliance testing is invaluable within the aviation industry. It helps maintain standards designed to provide passengers and crew with a high level of safety and security while travelling by air.

Standards testing for avionics

As aircraft electronics evolve, so do power requirements. Aircraft systems have grown from their original 115Vac L-N / 208Vac L-L at 400Hz fixed frequency to advanced on-board power systems operating at 115Vac and 230Vac and frequencies from 360 to 800Hz. This approach is known as 'wild' frequency. It simplifies the mechanical complexity of motor-driven electric generators. Onboard generators can now vary frequency with engine speed. Today, there are a number of standards for AC and DC power in space that both commercial and military aircraft systems must comply with. Commercial test standards for avionics such as DO-160 and EuroCAE 14 have a large number of immunity tests for AC current to be performed on airborne electronics.

More recently, several commercial aircraft manufacturers have developed their own version of these test standards, largely based on DO-160. Examples include Airbus ABD0100.1.8 (A380), ABD0100.1.8.1 (A350), Airbus AMD24C (A400M) and Boeing B787 (Dreamliner).Military avionics must comply with standards such as MIL-STD-704.These standards evolve in the same way as commercial standards. The products of, for example, Pacific Power Source have grown from being able to power avionics at 115 Vac and 400 Hz to full AC Power Compliance Test systems today. Sophisticated Windows operating software manages the test sets and provides product compliance documentation.