摘要
受限于散热条件,为了防止功率器件产生过大的开关损耗,进而减少服役寿命,轨道交通牵引逆变器开关频率通常低于1 kHz。逆变器运行至中、高频区域时,载波比下降导致其输出谐波增加,造成输出性能下降的同时导致电流峰值增大,使得绝缘栅双极晶体管(Insulated-gate Bipolar Transistor,IGBT)产生较大功率损耗,影响行车安全。针对现有低载波比的调制策略较多考虑输出性能的优化,而对IGBT功率损耗抑制考量较少的问题,文章提出一种针对牵引逆变器在五分频下的多目标优化调制策略,保证逆变器输出加权总谐波畸变较小的同时,降低总功率损耗。首先,根据逆变器负载模型建立输出电压与电流的数值与相位关系,根据器件厂商所提供的数据手册,从功率损耗产生机理出发,建立精确的IGBT功率损耗离散计算模型;其次,以逆变器输出电流谐波和功率损耗为优化目标,保证逆变器输出电压基波幅值与参考一致的前提下对开关角进行求解,实现逆变器多目标优化调制的目的。仿真结果表明,在工作区间内,与传统策略相比,所提优化调制策略显著降低了IGBT的功率损耗并保证了较优的输出性能。
Restricted by heat dissipation conditions,the switching frequency of the traction inverters for rail transit typically remains below 1 kHz,to prevent potential shortening of their service lifetime due to excessive switching losses in power devices.Inverter operation in the middle and high-frequency ranges results in a decrease in carrier ratio,leading to amplified output harmonics.This not only lowers output performance but also elevates peak current levels,intensifying power losses within the insulated-gate bipolar transistor(IGBT)and consequently undermining driving safety.Unlike existing modulation strategies to address low carrier ratios,which mostly focus on optimizing output performance while overlooking the suppression of IGBT power losses,this paper presents a multi-objective optimization modulation strategy for traction inverters under five-division frequency.This strategy aims to maintain a low weighted total harmonic distortion(WTHD)in the inverter output while reducing total power losses.Firstly,numerical and phase relationships between the output voltage and current were established based on the inverter load model.A precise discrete calculation model for IGBT power losses was developed based on the data manual provided by the device manufacturer,leveraging the power loss generation mechanism.Subsequently,the switching angles were solved under the premise of ensuring the fundamental amplitude of inverter output voltages aligned with the reference level,to enable multi-objective optimization modulation for inverters,including both inverter output current harmonics and power losses as optimization objectives.Simulation results indicate that within the operating range,the proposed optimization modulation strategy significantly reduced IGBT power losses and remained superior output performance compared to traditional strategies.
作者
金淼鑫
杜京润
范子寅
向超群
JIN Miaoxin;DU Jingrun;FAN Ziyin;XIANG Chaoqun(State Key Laboratory of Heavy-duty and Express High-power Electric Locomotive,Zhuzhou,Hunan 412001,China;CRRC Zhuzhou Locomotive Co.,Ltd.,Zhuzhou,Hunan 412001,China;School of Traffic&Transportation Engineering,Central South University,Changsha,Hunan 410075,China)
出处
《机车电传动》
2024年第2期51-58,共8页
Electric Drive for Locomotives
基金
重载快捷大功率电力机车全国重点实验室开放课题项目(QZKFKT2023-009)。
关键词
变流器
功率损耗
五分频
多目标优化调制
加权总谐波畸变
开关角
converter
power loss
five-division frequency
multi-objective optimization modulation
weighted total harmonic distortion
switching angle
作者简介
通信作者:向超群,男,博士后,副教授,硕士生导师,主要从事电力牵引传动技术方面的研究,E-mail:xcq061017@163.com。
