摘要
针对传统Z源逆变器电容电压应力高、启动冲击电流大、存在非正常工作状态、能量无法双向流动等缺点,提出了一种改进高性能双向Z源变流器拓扑。将改进型Z源逆变器中的二极管用一个带有反并联二极管的全控开关代替,通过对全控开关的控制,使Z源电感中的电流可反向流动,电感电压始终被钳位在电容电压,进而消除传统和改进型Z源逆变器在小电感或轻载下出现的非正常工作状态,保持直流链电压稳定。此外,控制电感电流的反向流动还可实现能量由交流侧向直流侧回馈。在理论分析的基础上,提出了一种改进型空间电压矢量调制策略。仿真结果表明,所提拓扑的电容电压应力和启动冲击电流比传统拓扑的更小,可在纯无功负载下运行,并可实现能量的双向流动。
To overcome the shortcomings of traditional Z-source inverter such as high capacitor voltage stress, high inrush current in start-up process, presence of abnormal working state, and unidirectional power flow, we have proposed a to- pology of improved high-performance bi-directional Z-source converter by replacing the diode with a full-controlled switch which has an anti-paralleled diode. By controlling this switch, the inductor current of Z source can flow reversely, and the inductor voltage is clamped to capacitor voltage. This method eliminates abnormal state at light load or small Z-source inductor conditions in traditional Z-source or improved Z-source inverter, and keeps DC link voltage stable. In addition, the proposed converter can implement dual power flow control by controlling the direction of the inductor cur- rent. On the basis of theoretical analysis, we put forward an improved space vector pulse width modulation strategy. The simulation results indicate that the proposed topology not only reserves the advantages of low capacitor voltage stress and small start-up inrush current, but also realizes the operation at reactive load and dual power flow.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2015年第10期3240-3248,共9页
High Voltage Engineering
基金
国家高技术研究发展计划(863计划)(2014AA052004)
国家电网公司科技项目(DG71–15–039)
国家自然科学基金(51207010)~~
关键词
Z源
变流器
轻载
双向流动
电压畸变
空间电压矢量
Z-source
converter
light load
bi-directional power flow
voltage distortion
SVPWM
