Eighteen-pulse rectifiers for harmonic mitigation

Multi-pulses rectifiers are one of the technical solutions for harmonic mitigation in AC adjustable speed drives. 12-pulse, 18-pulse and 24-pulse rectifier topologies are used in various technical applications. The paper presents results from experimental measurements and results from simulations for two topologies of the eighteen-pulse rectifiers: with Dy1z1+20
⁰
z1−20
⁰
and with Dd0diii0+20
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diii0−20
⁰
transformers. To simulate the behavior of the both eighteen-pulse rectifiers under various levels of voltage distortion a program written in FORTRAN in EMTP-ATP simulation program has been developed. Both experimental measurements and simulations demonstrate their high harmonic mitigation effectiveness. A comparison of the eighteen-pulse rectifiers with some other techniques for harmonic mitigation is also shown in the paper.