摘要
电力电子变压器除了能实现传统变压器的变压/隔离功能之外,还需要根据用户需求提供一些额外功能,其中之一是多输出功能,即给多个独立的交/直流负载供电。因为负载不平衡工况会对电力电子变压器的运行提出挑战,因此当设计一台具有多输出功能的电力电子变压器时,需要确定合适的拓扑与控制策略。本文对三种电力电子变压器拓扑的补偿不平衡负载的能力进行了比较,包括:独立相连接拓扑,交叉相连接拓扑与自平衡拓扑。独立相连接拓扑通过在输入级中注入零序分量来实现不平衡负载的补偿;交叉相连接拓扑通过输入级调制度以及无功分量注入实现不平衡负载的补偿;自平衡拓扑通过拓扑自身的连接方法以及多端口高频变压器实现不平衡负载的补偿,拓扑较为复杂。本文分析了上述三种电力电子变压器拓扑的原理以及控制策略,并在SIMULINK中验证了这几种拓扑补偿不平衡负载的功能。
Power Electronic Transformer （PET） can provide not only voltage level transform and isolation, but also some additional functions. The multi-output function, enabling the PET to drive multiple loads, is one of these ad- ditional functions. When driving multiple loads, there will be unbalanced load condition, which would bring chal- lenge to the PET＇s operation. Therefore, topologies and control strategies suitable for multi-load PET needs to be studied. This paper compares three different topologies on unbalanced load compensation capability, including se- perate-phase-connected topology, cross-phase-connected topology and self-balancing topology. The seperate-phase- connected topology handles the unbalanced load by zero sequence voltage/current injection into the input stage. The cross-phase-connected topology handles the unbalanced load by adjusting the modulation indexes of modules within a input stage cluster or injecting reactive component into the input stage. The self-balancing topology handles the unbalanced load by the topology itself and the use of multi-winding high frequency transformer. This paper ana- lyzes the operation principle and control strategy of these three topologies. The unbalanced load compensation func- tion of the three topologies is verified by Simulink.
出处
《电工电能新技术》
CSCD
北大核心
2017年第5期11-20,共10页
Advanced Technology of Electrical Engineering and Energy
关键词
电力电子变压器
多输出
不平衡负载
拓扑
power electronic transformer
multi-output
unbalanced load
topology
