E.T.S. de Ingenieros Industriales
New challenges for the Active and Isolated Rectifier Units (High performance TRUs) to support the MEA concept are demanding deep changes compared with the conventional TRUs. INDRA and CEI-UPM, the consortium that is presenting this proposal, has a wide experience in the area of high performance TRUs for the new aircraft requirements The basic architecture that allows for these high performance TRUs has three stages: 1) EMI filter to meet the EMI standards, 2) Active Three-Phase rectifier to control the demanded sinusoidal current (THD and PFC) as well as control the output dc voltage (VBUS DC) and 3) isolated dc/dc converter that provides galvanic isolation, adapts the voltage and power to the
specifications (28V) and it can be in charged of some control capabilities (battery charge mode, voltage source mode, current source mode, some protections).
Within this project, this basic architecture will be considered and compared with the multiphase solution (several converters shifted and operating in parallel) as well as some active and isolated rectifiers proposed in the state of the art. For the isolated dc/dc stage, advanced topology solutions with soft transitions will be analysed since they allow to operate at higher
frequencies, reducing the weight of the final unit. A topology recently proposed by UPM-CEI  is really appropriate for this application since it presents almost zero switching losses.
A review of the state of the art has been done and the consortium is proposing to meet about 1.5kW/kg for the whole EMI + AC/DC + isolated DC/DC. This objective is based on the experience in previous project, and it is a goal beyond of the state of the art (about +20% or +25% higher power/weight ratio). It is doable thanks to the use of high frequencies combined with soft switching techniques. Besides, the use of new SiC and GaN semiconductors will be analysed and consider in the design since they allow for higher temperature operation as well as higher frequencies.