单相PET级联整流SVPWM均压边界及拓展方法
Voltage Balancing Boundary and Extension Method of SVPWM for Single-phase Cascaded Rectifier Based on PET
王顺 1马兰 1朱磊磊 1杨帆 1谢锡锋 2舒泽亮1
作者信息
- 1. 西南交通大学电气工程学院,成都 610031
- 2. 西南交通大学电气工程学院,成都 610031;广西水利电力职业技术学院,南宁 530023
- 折叠
摘要
电力电子变压器(power electronic transformer,PET)是交直流配电系统互联的重要接口设备,然而后级等效负载不平衡将造成前级整流器各模块的电压偏移.针对单相级联H桥整流器空间矢量调制均压失效问题,推导出基于最优矢量选择均压策略的边界计算方法.根据计算所得的负载不平衡度限制边界与级联模块数、调制度以及功率因数的关系,提出了变调制度和功率因数的控制策略以增加均压能力.该策略通过改变直流电压或降低功率因数来重建更宽的均压工作范围,确保原不平衡度均压极限的系统稳定运行.最后,通过三模块级联整流器的仿真与实验验证了该均压边界的正确性,以及所提均压拓展方法保障极端不平衡负载条件下均压的有效性.
Abstract
Power electronic transformer is an important interface device for connecting AC/DC power distribution sys-tems in the renewable energy generation grid.However,the DC voltage of the front-stage single-phase cascaded H-bridge rectifier will deviate because of the back-stage unbalanced load.In this paper,the voltage balancing boundary based on the optimal vector selection strategy is derived to solve the problem that space vector pulse width modulation(SVPWM)fails to balance the voltage.According to the relationships between the load unbalance index boundary and the number of cascade cells,modulation index,and power factors,a control strategy is proposed.The voltage balancing capability can be improved by changing the modulation index or power factors.Therefore,to ensure stable operation under severe un-balanced load conditions,a wider voltage balancing range is established by changing the DC voltage reference or reducing power factors.The balancing boundary and the effectiveness of the proposed expansion method,which guaran-tees equalization under extremely unbalanced conditions,are verified by simulation and experimental results with a three-cell cascaded rectifier.
关键词
电力电子变压器/单相级联H桥整流器/直流电压均衡/均压边界/负载不平衡限制边界Key words
power electronic transformer/single-phase cascaded H-bridge rectifier/DC voltage balance/voltage bal-ancing boundary/boundary of load unbalance index引用本文复制引用
基金项目
国家自然科学基金(52077183)
广西壮族自治区高等学校高水平创新团队及卓越学者计划(桂教人才[2020]6号)
出版年
2024
国家科技期刊平台
NSTL
万方数据