摘要
模块化直流固态变压器(DC-SST)可以实现不同直流电压等级之间的电气隔离、电压变换和功率传输,在直流配电系统中具有重要的作用。对不同调制策略下DC-SST系统内高频变压器的电压、电流特性和功率传输能力进行了对比分析,验证了准方波调制策略下DC-SST系统能保证高效的电能传输能力。在此基础上,对准方波调制下DC-SST系统的子模块工作模态进行了分析,推导了系统的软开关约束条件,并研究了系统的子模块均压策略和总体控制策略。最后,在MATLAB中对准方波调制下DC-SST系统的控制策略进行仿真并验证其有效性。
DC solid state transformer(DC-SST)based on modular multilevel converter,which plays an important role in the DC distribution system,can achieve electrical isolation,voltage conversion and power transmission between different DC voltage levels.The voltage,current characteristics and power transmission capacity of high-frequency transformer of DC-SST system among different modulation strategies were analyzed and compared.It is verified that the DC-SST system based on quasi-square-wave modulation can guarantee the efficient power transmission.On this basis,the working modes of sub-module of DC-SST system based on quasi-square-wave modulation were researched and the system’s soft-switching conditions were deduced.Moreover,a voltage-balancing strategy of sub-module and overall control method were analyzed.The effectiveness of the control method was validated in MATLAB.
作者
汪泓
孙海翔
季振东
WANG Hong;SUN Haixiang;JI Zhendong(School of Electrical Engineering,Southeast University,Nanjing 210096,China;Nanjing University of Science and Technology,Nanjing 210094,China)
出处
《电器与能效管理技术》
2018年第20期36-43,共8页
Electrical & Energy Management Technology
基金
国家自然科学基金(51707098)
江苏省自然科学基金(BK20170841)
关键词
直流固态变压器
准方波调制策略
软开关
子模块均压策略
DC solid state transformer
quasi-square-wave modulation strategy
soft-switching
voltage-balancing strategy of sub-module
