Optimization and verification of aviation 18 pulse autotransformer rectifier unit

The steady-state output voltage of the currently developed 18 pulse autotransformer rectifier unit (ATRU) does not meet the requirements of the international standard ISO24071 which released in August 2022.To address this issue, this paper proposes an optimization method of symmetrical D-type 18 pulse ATRU, which based on the reasonable design of the number of turns and connection of the autotransformer windings. Theoretical analysis and calculation of the output voltage, input current, equivalent capacity and the winding current of the ATRU are conducted. The results of this paper are verified by a MATLAB simulation model and a 3kW prototype developed in lab and indicate the performance of the optimized ATRU meets the steady-state output voltage requirements of the ISO24071.