Powering 270 V DC Equipment from 230 V AC Aircraft Bus 2012-01-2223

Aircraft electrical power consumption has dramatically increased in recent years. Technological advancements have led to the replacement of traditional hydraulic and pneumatic systems with electrically powered devices. In addition, new functions such as deicing and entertainment systems have been added, which further increases the demand for electrical power. As power needs increase, voltage or current, or both, must be increased. Increased current can be the least desirable result as it leads to larger and heavier wires. To mitigate the issue of wire weight and distribution losses, the latest “More Electric Aircraft” have adopted 230 V ac as the main power bus voltage. However, this presents a problem as a significant amount of existing electrical aircraft equipment (actuators, pumps, etc.) have been designed to use 270 V dc power, which is obtained by a direct rectification of 115 V ac power. Two hundred seventy volts dc cannot be as simply produced from a 230 V ac bus.

This paper provides details on new practical ATRU topologies that convert 3-phase 230 V ac into 270 V dc. Designs of 12-pulse and 18-pulse ATRUs are addressed. A design example of 230 V ac to 270 V dc ATRU is covered in the paper. Also, performance results from demonstration hardware, including power quality, regulation, efficiency, and reliability are provided.