This paper proposes a novel multi-pulse flexible-topology thyristor rectifier (FTTR) that can operate over a large voltage range while maintaining a low total harmonic distortion (THD) in the input current. The proposed multi-pulse FTTR has two operating modes: parallel mode and series mode. Irrespective of the mode in which it operates, the multi-pulse FTTR maintains the same pulses in the load current. To mitigate the harmonic injection into the AC mains, the topology-switching mechanism is then proposed. In addition, predictive current control is employed to achieve fast current response in both the transience and the transitions between modes. To verify the effectiveness of the multi-pulse FTTR as well as the control scheme, performance analysis based on an 18-pulse FTTR is investigated in detail, including fault tolerance evaluation, current THD analysis based on IEEE standard, and potential applications. Finally, a simulation model and the corresponding laboratory setup are developed. The results from both simulation and experiments demonstrate the feasibility of the proposed multi-pulse FTTR as well as the control scheme.

关键词： Flexible-topology operation,  Multi-pulse thyristor rectifier,  Predictive current control,  Fast current response,  Fault tolerance evaluation