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In recent years, More-Electric and All-Electric Architectures are being adopted extensively for next generation of aircraft. In this new architecture, many systems rely primarily on the use of electrical energy. Hence, there is a significant increase in the demand of electrical energy that is managed by the electric power system of the aircraft. A significant increase in demand of electrical power is also observed during recent years of aircraft development. In the More-Electric Architecture, aircraft systems are heavily dependent on electric energy. This fact results in higher extraction of mechanical power from the engine via power take off shafts as opposed to energy extraction via bleed air. The balance of extracted energies has shifted from pneumatic extraction to mechanical extraction and conversion into electrical power. The transition to the use of increased levels of electrical power leads to increased complexity and criticality of the electrical system of the aircraft.

New trends in design of electric power systems for the next generation of aircraft, (more electric aircraft, variable frequency electric power systems, etc.), require new technologies for DC power supply and AC/DC conversion. Advancement in power electronics and in power distribution technologies favor the development of concepts of power distribution and conversion with improved electric power performances. This paper presents the main characteristics and performances related to design and integration of the Honeywell Regulated Transformer Rectifier Unit (RTRU) in a DC electric power system. The design requirements for this new concept RTRU were developed from studies and analysis of existing and foreseen future power systems needs. Conclusions and recommendations on the use and integration of the RTRU were developed based on studies, simulation, analysis and testing.

Widely used in turbo-prop and business jets, Variable Frequency (VF) Electrical Power Systems are beginning to gain acceptance in the aviation industry. Commercial jet aviation manufacturers and systems integrators are interested because of the potential cost and weight savings VF systems offer. However, compatibility with conventional utility equipment that operates on 400Hz, fixed frequency (FF) still remains an issue in converting to VF power. This paper addresses considerations for the use of VF power in aircraft electrical power systems. It primarily identifies some of the difficult areas associated in the conversion over to VF using legacy equipment. The paper also provides the results of testing and modeling, and suggests alternate system configurations in adapting utilization equipment for VF use.

This paper presents the main characteristics related to the design and integration of the Electrical Power Generation and Distribution System (EPGDS) performed by Allied Signal Aerospace Canada for the Bombardier - deHavilland DHC-8 Series 400 airplane. It provides an overview of the system, and describes the development process and the various technical challenges along the way. The EPGDS comprises of a variable frequency AC Power Subsystem and a DC Power Subsystem. Since the commercial aviation industry is showing increasing interest in variable frequency power systems, this paper provides some focus on the use of variable frequency AC power on the Dash 8 platform and its impact on frequency sensitive equipment.