Development of a highly reliable power electronic unit for helicopters

This paper introduces a concept for a reliable and miniaturized power control unit (PCU). With this PCU, an electro-mechanical actuator (EMA) is controlled. This EMA is intended to be used in a swashplateless helicopter control system. As this is a safety relevant part of the helicopter, the PCU needs to work reliably under challenging ambient and operating conditions. At the same time, the whole assembly including heat sink, DCB with power electronic switches, driver board, dc-link and cabling needs to fit into 3.2 litres installation space. All the points mentioned necessitate a careful choice of components and packaging materials to achieve the claimed reliability in limited space.