Optimum Design of an 18-Pulse Phase Shifting Autotransformer Rectifier to Improve the Power Quality of Cascaded H-Bridge Motor Driver

Abstract

Due to its simplicity, efficiency, and dependability, the multipulse rectifier is widely used in electrical systems. In the presented work, an optimum design of an 18-pulse rectifier is achieved by comparing the most used configurations on the market. The 18-phase shifting autotransformer (18-PSAT) rectifier is a cheaper alternative to conventional rectifiers to reduce system harmonics. After a thorough study of the market needs and available use, this paper discusses four different structures that provide harmonic levels according to IEEE 519 limitations. An innovative 18-PSAT is shown, studied, simulated, produced, and tested with low power loss rates. The Delta differential configuration primarily emphasises lowering the loss power rating for improved power quality. With its simple structure, easy assembly, and direct connection to diodes, the proposed Delta differential configuration provides higher power quality and can cancel harmonics. To determine which 18-PSAT rectifier unit has the best weight, size, and power quality, a comparison of the selected topologies is made. A comprehensive comparison of each topology has simulation results showing current, voltage, and total harmonic distortion (THD) using MATLAB Simulink. The simulation results show that the total harmonic distortion is under 2.9 % when adopting the suggested Delta differential configuration topology. Compared to other designs, the suggested 18-pulse layout reduces overall cost and footprint by a large margin. It is also demonstrated that the DC load power is about 85 % of the recommended rectifier rating.