A 24-pulse Rectifier with A Single-phase Uncontrolled Rectifier in Series at DC Side

In order to optimize the power quality of a 12-pulse rectifier, a 24-pulse rectifier topology based on a single-phase uncontrolled rectifier cascaded at DC side is designed in this paper. The scheme achieves a significant improvement in system performance by integrating an interphase reactor with auxiliary windings and a single-phase uncontrolled rectifier module on the basis of the traditional 12-pulse rectifier. The output current of the main power bridge is modulated by the additional SUR at DC side, which doubles the number of input current step waves based on the relationship between the currents on the AC and DC sides. The pulse number of output voltage is increased from 12 to 24 steps by superposing the output voltages of the SUR and the main rectifier bridge. The experimental results show that the pulse number doubling effect can be achieved by only configuring a small-capacity SUR module, and the scheme effectively suppresses the harmonic components of the input-side current and the ripple coefficient of the output-side voltage while maintaining the symmetry of the topology and easy-to-implement performance. The modelling and analysis results based on the simulation platform fully verify the correctness and effectiveness of the proposed method.