Revolutionizing Aerospace Power Management: Advancements in Smart Contactors

By Karl Kitts, Serves as senior manager, advanced system architecture for the global aerospace, defense

and

marine business unit of TE Connectivity.

Aerospace power systems are at the crux of an emerging revolution. As our skies become populated with sophisticated increasingly electrified aircraft, a wide array of drones and even electric vertical takeoff and landing (eVTOL) vehicles, a fresh approach to aerospace power management is paramount. Amid this innovative flurry, contactors have been steadily evolving into intelligent power management tools that extend beyond traditional power control, providing insightful diagnostic information that enhances system reliability.

Contactors, traditionally seen as simple electromechanical switches, have undergone remarkable transformation. Contemporary contactors feature integrated electronics, sensors and communication capabilities, redefining their role in aerospace applications. Advanced contactors, commonly referred to as “smart contactors,” have shown promise in not only efficiently managing power flow but also providing fault detection and prediction, thus ensuring optimal performance.

Monitoring and Control: The Backbone of Power Management

Today’s smart contactors seamlessly monitor and control power flow by leveraging a variety of sensing techniques. Resistive sensing, for instance, uses a precision resistor to gauge current flow. Despite its accuracy, resistive sensing has some drawbacks, such as generating excessive heat, particularly in high-current contactors. Other approaches like current transformers (CTs) and Hall-effect sensors measure the magnetic field created by the current to monitor power flow.

Hall-effect sensors, in particular, offer several benefits, including excellent isolation between primary and secondary circuits, high accuracy, superior dynamic performance and exceptional reliability. Despite the type of sensor chosen, supporting electronics are vital to collecting information, thereby making intelligent decisions on system configuration.

Smart contactors offer the ability to react autonomously to overload fault conditions, delivering rapid response times. What’s more, these contactors can be customized for specific load requirements through various means like connector pin programming, DIP switches, external resistor additions or software coding, underscoring their flexibility.

Broadening Horizons: Beyond Overcurrent Protection

While overcurrent detection is a primary role for smart contactors, these advanced devices can also detect a variety of other fault types. For instance, phase faults, including loss of phase and improper phase rotation, can be sensed to ensure efficient three-phase power delivery. Leakages and ground faults can be detected via multiple sensors along the wiring path, helping identify faults and prevent electrical failures.

Arc fault detection is another critical feature of modern smart contactors. Traditional protective devices often overlook these faults, which can lead to overheating. Arc faults detection is a powerful tool that allows preemptive measures, averting potential system damage.

Redefining Contactors: Solid-State Revolution

The advent of power semiconductors has paved the way for solid-state relays, an exciting development for contactor technology. By replacing power contacts with metal-oxidesemiconductor field-effect transistors (MOSFETs), the solid-state approach promises enhanced reliability due to the elimination of moving parts. However, the increased thermal output of these devices necessitates careful heat management strategies to avoid failure.

The “hot-switching” challenge associated with contactors has gained prominence with the industry’s push toward more electric aircraft

(MEA). This is where hybrid contactors come into play. A hybrid contactor combines the low ON resistance of an electromechanical contactor with the non-arcing power switching of power electronics. This technology can substantially increase the hot-switching life for high-voltage DC (HVDC) contactors.

Another promising innovation is the SolidState Power Controller (SSPC), which merges a full solid-state power switch with monitoring and communication features. These smart devices can be configured remotely, thereby improving system reliability and availability.

From Sensing to Prediction: The Future of Contactors

With integrated microcontrollers, smart contactors and SSPCs can collect and analyze crucial operational data, enabling fault prediction and offering timely, flexible responses. The monitoring of real-time current and voltage levels can provide insight into the health of the contactor as well as the overall aircraft electrical system. For instance, observing data related to running currents, temperature and the number of cycles can enable predictive maintenance, thus extending the life of the contactor.

This data-driven approach extends beyond contactor health. For instance, initial power-up current draw can reveal inrush currents to motors or pumps, providing insight into components like bearing wear. This intelligence can help schedule timely lubrication and maintenance tasks, preventing potential component failure.

When compared over time, this operational data can reveal significant insights into system health. Spotting trends in sensor data can enable early detection of faults in the wiring system, further ensuring system reliability.

Harnessing Data: Enhancing System Health and Predictive Maintenance

Aerospace is a domain that presents several unique challenges. Contactors must function in demanding environments and ensuring their optimal performance is crucial for safe and efficient aircraft operations. A comprehensive approach to monitoring and data analysis can provide a holistic understanding of the system’s health.

The concept of harnessing data for better predictive maintenance can be scaled up, using multiple devices and additional sensors throughout the wiring system to create a holistic “big picture” overview. This data can then be utilized for advanced analysis and prediction, fostering a comparison of conditions across the system and allowing for the anticipation of potential problems.

Integrated Assemblies: The Future of Aerospace Power Management

As contactors become increasingly complex and sophisticated, many industry players are opting for custom-designed, applicationspecific power panels as an all-encompassing power management and distribution solution. These panels, which house not just relays and contactors but also control electronics, can provide advanced monitoring and control capabilities. These plug-and-play solutions exemplify the future of power distribution in the aerospace industry, integrating all required components in a compact, custom package.

Embracing Intelligent Power Management for Aerospace Applications

In a rapidly evolving aerospace landscape, smart contactors, hybrids and SSPCs are revolutionizing power management. By harnessing the power of integrated electronics, sensors and advanced communication features, these next-gen devices are taking on a central role in power distribution, fault management and system health analysis.

In this era of advanced digital technology, it’s vital to embrace these technological strides, redefining the potential of power management in the aerospace industry. As the skies become more congested with diverse aircraft types, including those operating new missions, ensuring efficient power management and fault prediction will be key to maintaining the high standards of safety and reliability for which the aerospace industry is renowned.

Technology often has a habit of advancing at an ever-accelerating pace, especially in a field as dynamic and critical as aerospace. The future, it seems, lies in smart contactors and SSPCs, which are revolutionizing the power management landscape by effectively marrying traditional contactor technology with advanced digital capabilities.

A significant shift observed in this domain is the move toward hybrid contactor designs. These intelligent devices blend the low ON resistance advantage of traditional electromechanical contactors with the non-arcing power switching capabilities of power electronics. This combination not only eliminates a significant wear-out mechanism within the contactor but also drastically enhances the hot-switching life for High Voltage Direct Current (HVDC) contactors, providing an attractive solution for applications requiring numerous hot-switching cycles.

On the other hand, SSPCs are emerging as highly effective power management tools. An SSPC brings together a full solid-state power switch and multiple monitoring and communications capabilities. This combination offers an integrated overcurrent trip curve that guards the wiring interconnects and the load against excessive current draw or short circuits. SSPCs can communicate for command and status over a vehicle data bus, enhancing system reliability and availability. High voltage

SSPCs even come equipped with a built-in precharge feature, which allows efficient power up while reducing surge currents.

The transition from traditional contactors to these advanced technologies is driven by the constant quest for efficiency, reliability and longevity in the aerospace sector. Not only do these solutions offer enhanced performance, but their intelligent, data-driven operations allow for predictive maintenance, thus reducing unplanned downtime and extending system life.

As a new era emerges, it’s evident that the aerospace industry is standing on the cusp of a significant shift in power management. Smart contactors, hybrids and SSPCs, coupled with advanced data analysis, are poised to redefine the understanding of system health and application of predictive maintenance. Such advancements are expected to further bolster the industry’s laudable commitment to safety, reliability and efficiency in the skies.

Karl Kitts serves as senior manager, advanced system architecture for the global aerospace, defense and marine business unit of TE Connectivity. With more than 35 years’ experience, his expertise is in high-current military and aerospace power distribution, electrical relays and power contactors, electronics circuit protection, HVDC relays, sensors, time delays and solid-state devices. Connect with Karl Kitts at www.DesignSmarterFaster.com.