A Series-connected 24-pulse Rectifier for Direct-drive Wind Power Generation System

In traditional direct-drive wind power generation systems based on diode rectification units, the nonlinearity of rectifying diodes can lead to severe harmonic pollution. In order to improve the harmonic suppression capability of the diode rectification unit, this paper proposes a 24-pulse rectifier based on passive harmonic suppression method on the DC side. This rectifier utilizes a passive harmonic suppression circuit to modulate and generate square wave circulating currents, increasing the number of rectifier pulses from 12 to 24. Firstly, the working principle of the diode rectifier is analyzed. Secondly, the mechanism of harmonic suppression in the rectifier is explained, and the turns ratio of the injection transformer is designed and optimized with the objective of minimizing current harmonics. Theoretical analysis and simulation verification demonstrate that this rectifier has strong harmonic suppression capability and high reliability, making it suitable for direct-drive wind power generation systems.