计及主动冗余的海上直流风电机组并网混合MMC损耗建模与分析  

Power Loss Modeling and Analysis of Hybrid MMCs with Active Redundancy for Offshore DC Wind Turbines

作　　者：李辉[1] 谢翔杰 吴优 Alasdair McDonald 杨微 LI Hui;XIE Xiangjie;WU You;Alasdair McDonald;YANG Wei(State Key Laboratory of Power Transmission Equipment&System Security and New Technology,Chongqing University,Chongqing 400044,China;Faculty of Engineering,University of Strathclyde,Glasgow G11XW,UK;CSIC(Chongqing)Haizhuang Windpower Equipment Co.,Ltd.,Chongqing 401122,China)

机构地区：[1]重庆大学输配电装备及系统安全与新技术国家重点实验室,重庆400044 [2]思克莱德大学工程学院,格拉斯哥G11XW [3]中船重工(重庆)海装风电设备有限公司,重庆401122

出　　处：《高电压技术》2021年第8期2655-2667,共13页High Voltage Engineering

基　　金：国家自然科学基金(51761135014,51675354);中央高校基本科研业务费(2019CDXYDQ0010)。

摘　　要：针对仿真计算法难以在设计初期快速评估混合模块化多电平变流器(hybrid modular multilevel converter,HMMC)损耗,而现有解析模型主要针对单一结构子模块(submodule,SM)组成的模块化多电平变流器(modular multilevel converter,MMC)且未考虑主动冗余对损耗影响的问题,提出了一种计及主动冗余的损耗解析模型。首先,考虑固定电平(fixed level,FL)与电压均分(voltage sharing,VS)2种主动冗余模式,分析半桥与全桥SM的调制策略;然后根据SM功率器件的导通与开关状态,建立不同冗余模式下HMMC损耗的解析模型;最后,以10 MW、10 kV的海上直流风电机组HMMC为例,通过仿真验证所提损耗模型的有效性,并分析比较不同冗余模式及SM结构对HMMC损耗的影响。结果表明:额定风速下,HMMC总损耗随冗余半桥SM(half-bridge SM,HBSM)或全桥SM(full-bridge SM,FBSM)的增加基本呈线性关系;相比FL模式,VS模式下总损耗随冗余HBSM变化较小,但受冗余FBSM影响较大。研究可为海上直流风电机组并网MMC的损耗计算提供理论依据。The simulation method is not applicable to rapidly assessing the power loss of hybrid modular multilevel converter(HMMC)at initial design stage,and existing analytical models mainly focus on the modular multilevel converter(MMC)constituted by submodules(SMs)with the same structure,without taking into account the impacts of active redundancy.Therefore,we proposed an analytical power loss model for HMMC with active redundancy.Firstly,both fixed level(FL)and voltage sharing(VS)redundancy modes were taken into consideration,and the modulation strategies of half-and full-bridge SMs were analyzed.Then,according to the conduction and switching states of power devices in SMs,the analytical approach to power loss of HMMC with different redundancy modes was derived.Finally,by taking a 10 MW and 10 kV MMC as an example,the efficacy of the proposed model was verified through simulations.Moreover,the influences of different redundancy modes and SM structures on power loss were analyzed and compared.The results show that,at the rated wind speed,the total loss of HMMC almost linearly increases with the increase of redundant half-bridge SMs(HBSMs)or full-bridge SMs(FBSMs).Compared with that in the FL mode,the total loss change with redundant HBSMs is slighter in the VS mode,which becomes greater with redundant FBSMs.The research can provide a theoretical basis for the loss calculation of grid-connected MMC for offshore DC wind turbine.

关 键 词：海上直流风电机组 模块化多电平变流器 主动冗余 混合子模块 损耗计算 

分 类 号：TM315[电气工程—电机]