Electrical System Protection Device of an aircraft

The advancement in aircraft technology has resulted in the substitution of hydraulic, pneumatic, and electronic devices with electrical ones. The development of all electrical aircraft has opened up new prospects in control electronics and mobile devices. The category of safety systems and the management of loads by solid-state power controllers are among the core areas of growth, owing to the increased use of these devices in electrical power delivery in modern aircraft such as the B787. As a result, this paper is obligated to address aircraft electrical device safety technology in onboard platforms. In addition talk about the virtual test, bench developed to analyze the potential problems that could occur when using solid state power controllers (SSPC) in protection devices.

The electrical systems used in the aircraft provide better performance, high general efficiency, and lower maintenance. However, the power electronic devices (PDS) have a significant role in the new power distribution systems because of the high rate at which power is transferred to the load. The protection mechanisms of these new PDS are replacing the traditional security devices. In the new architectures of the all electrical aircraft, very high voltage levels have to coexist with the old voltage levels and the devices powered by these old voltages. As a result, these structures comprise of a primary high voltage main distribution and secondary distribution buses that control the conventional levels of voltage. The new designs appearing in the electrical aircraft power electronic devices depend largely on power electronic. It is evident that the increase in power electric demand provokes an increase in the alternating current and direct current of the primary distribution. Therefore the main aim is to minimize the conduction losses, and reduce the wire size by decreasing the levels of current; these will also result in reduced weight and volume of the aircraft (Izquierdo et al., 2011).

The onboard protection devices that have been used to control current levels and detect faults include the arc fault circuit breaker, circuit breaker, remote controlled circuit breaker, and solid state power controllers. The most popular wire protection equipment in the 28 dc voltage and 115 ac voltage design of the PDS is the circuit breaker. However, the circuit breaker cannot reveal the arc failure because of its limited time duration. The reason why SSPC has evolved is that it combines the role of connecting loads to the main bus and the function of protecting the electric mountings from overloads and short circuits. SSPC also boasts other characteristics such as low power dissipation, remote control capability, and high reliability. The use SSPC technology has improved the PDS monitoring and wire protection (Izquierdo et al., 2011).

In addition to onboard protection, the electrical systems of the aircraft need to be protected from lightning. It is terrifying to fly during an electrical storm, with lightning paths moving from cloud to ground; an aircraft flying in the rain can sometimes form part of the path. Traditionally, the aircraft frames were made of aluminium which accommodated the lightning paths. Recent trends have pushed manufacturers to use composite materials to construct their structures. Although they are attractive, light and more fuel efficient, their lightning protection capability should also be considered. Researchers are therefore exploring the possibility of using silicon carbide based equipment to protect aircraft electrical systems (Ford, 2015).

References

Izquierdo, D., Barrado, A., Raga, C., Sanz, M., & Lázaro, A. (2011). Protection devices for aircraft electrical power distribution systems: State of the art. IEEE Transactions on Aerospace and Electronic Systems, 47(3), 1538-1550.

Ford, J. (2015). Silicon carbide based devices to protect aircraft electrical systems. Retrieved September 2, 2017, from https://www.theengineer.co.uk/issues/march-2015-online/silicon-carbide-based-devices-to-protect-aircraft-electrical-systems/