摘要
采用DAB(双有源全桥变换器)拓扑的直流变压器具有较好的ZVS(零电压开通)特性,为器件直接并联缓冲电容实现无损关断缓冲提供了依据。首先介绍了IGCT-HDCT(基于集成门极换流晶闸管的大容量直流变压器)的结构与运行控制。之后提出了一种基于软换流的黑启动策略,通过将启动过程分为扩展移相启动阶段与单移相启动阶段,实现了IGCT-HDCT黑启动过程中全部器件的ZVS,缓冲电容无浪涌电流产生。通过分析器件关断后的谐振过程,给出了拓展移相启动阶段内移相与系统参数的关系,并证明了单移相启动阶段器件的ZVS特性。通过预测控制以及占空比设计,消除了系统瞬态偏置电流。最后利用1.5kV/2 MW的实验样机验证了所提控制策略的可行性。
The DC transformers with dual active bridge(DAB)topology is characterized by zero voltage switching(ZVS)and provides the basis for realizing lossless turn-off buffer by directly paralleling buffer capacitors.First,the structure and operation control of IGCT-HDCT(IGCT-based high-capacity DC transformer)are introduced.Then,a black startup strategy based on a soft converter is proposed,which divides the start process into the extended phase shift and single phase shift startup to realize the ZVS of all devices during the black startup of IGCT-HDCT and prevent the surge current on the buffer capacitor.By analyzing the resonance process of the device after shutdown,the relationship between the phase shift and the system parameters in the extended phase shift stage is introduced,and the ZVS characteristics of the device in the single phase shift stage are verified.The transient bias current of the system is eliminated by predictive control and duty ratio design.Finally,the feasibility of the proposed control is verified by a 1.5 kV/2 MW prototype.
作者
汤雪腾
马已青
史兴华
裘鹏
黄晓明
赵彪
TANG Xueteng;MA Yiqing;SHI Xinghua;QIU Peng;HUANG Xiaoming;ZHAO Biao(Department of Electrical Engineering,Tsinghua University,Beijing 100000,China;State Grid Zhejiang Electric Power Co.,Ltd.,Hangzhou 310007,China;State Grid Zhejiang Electric Power Co.,Ltd.Research Institute,Hangzhou 310014,China)
出处
《浙江电力》
2023年第6期14-22,共9页
Zhejiang Electric Power
关键词
直流变压器
黑启动
零电压开通
DC transformer
black start
zero voltage switching
