Harmonic Mitigation in Multi-Pulse Rectification: A Comparative Study of 12-, 18-, and 24-Pulse Systems

In the evolution of the modern "More Electric Aircrafts" (MEAs) concept, higher-pulse rectification systems using differential fork autotransformers play a pivotal role. These systems align with the MEAs concept, which aims to replace traditional hydraulic and pneumatic systems with electric alternatives. The reason is that MEAs prioritize weight reduction to enhance fuel efficiency and reduce emissions. Higher-pulse rectifiers achieve this by minimizing losses and optimizing power conversion. Additionally, they mitigate harmonics, ensuring a clean power supply to critical avionic components. These systems also regulate voltage effectively, contributing to overall system stability. Furthermore, their compliance with IEEE-519 standards ensures their safe and efficient operation. Keeping in view the above applications, a comparative study of 12-, 18-, and 24-pulse rectification systems was carried out using different autotransformer topologies. The simulation and hardware results are presented for validation. The voltage and current waveforms were meticulously analyzed for each topology, emphasizing the pivotal role played by the differential fork autotransformer design. By quantifying the total harmonic distortion (THD) levels using MATLAB simulations, intriguing insights were revealed. Notably, the 24-pulse system emerged as the clear winner in harmonic mitigation, showcasing its superior waveform quality and reduced harmonic content. However, the 18-pulse configuration also exhibited a commendable performance, surpassing the 12-pulse counterpart.