一种适用于HVDC带双无源谐波注入的串联型36脉波整流器

A series-connected 36-pulse rectifier for HVDC with a dual passive harmonic injection method

为了提升海上风电并网HVDC系统中的串联型二极管多脉波整流器的谐波抑制能力,提出一种基于直流回路双无源注入电路的串联型36脉波整流器。该整流器采用两个辅助无源注入电路,通过电流调制后产生电压注入谐波,最终可将交流侧输入相电压由12阶梯波倍增至36阶梯波。分析了双无源注入电路工作原理及特性。在此基础上,推导了整流器交流侧输入电压表达式。并以电压谐波畸变率最小为目标,设计了注入变压器的匝比参数。最后结合工程应用,讨论了辅助无源电路中二极管开路故障时系统的容错能力。理论分析及仿真结果表明,所提出的整流器具有谐波抑制能力强、结构简单、可靠性高和鲁棒性强等优点,更适用于高电压大功率场合。

To improve the harmonic suppression ability of series-connected diode multi-pulse rectifiers in an offshore wind power grid-connected HVDC system,a series-connected 36-pulse rectifier based on a dual passive injection circuit at the DC side is proposed.The rectifier adopts two auxiliary passive injection circuits,which generate voltage injection harmonics after current modulation,and which can double the AC input voltage waveform from 12-step to 36-step.The principle and characteristics of dual passive injection circuits are analyzed in this paper.The input voltage expression at the AC side of the rectifier is derived,and the turn ratio parameters of the injection transformers are designed to minimize the voltage harmonic distortion rate.Finally,the fault-tolerant capability of auxiliary passive circuits with diode open circuit faults is discussed.Theoretical analysis and simulation results show that the proposed rectifier has the advantages of strong harmonic suppression,simple structure,high reliability,and strong robustness,and is more suitable for high-voltage and high-power application.