构建虚拟桥臂数学模型的MMC阀损耗快速计算方法研究  

Power Loss Calculation for MMC Valves on Virtual Arm Mathematical Model

作　　者：李探 尹诗媛 姚志 陈东 尹太元 王璋 LI Tan;YIN Shiyuan;YAO Zhi;CHEN Dong;YIN Taiyuan;WANG Zhang(State Grid Economic and Technological Research Institute,Changping District,Beijing 102209,China;State Key Laboratory of Electrical Insulation and Power Equipment(Xi’an Jiaotong University),Xi’an 710049,Shaanxi Province,China;State Grid Ningxia EPRI,Yinchuan 750001,Ningxia Hui Autonomous Region,China)

机构地区：[1]国网经济技术研究院有限公司,北京市昌平区102209 [2]电力设备电气绝缘国家重点实验室(西安交通大学),陕西省西安市710049 [3]国网宁夏电科院,宁夏回族自治区银川市750001

出　　处：《电网技术》2019年第12期4509-4516,共8页Power System Technology

基　　金：国家电网公司科技项目(52010118000B)~~

摘　　要：准确计算MMC阀损耗对柔性直流输电工程设计具有重要意义。目前计算MMC阀损耗的方法存在数学解析计算不准确或者需要运行电磁仿真而耗时过长的问题。提出了一种简化的MMC仿真模型:虚拟桥臂数学模型(virtualarm mathematical model,VAMM),基于此模型能够准确快速的计算出不同工况、不同调制及均压策略下的瞬时功率损耗。文章首先介绍了虚拟桥臂数学模型的基本结构,然后推导了MMC阀损耗计算的通用方法,并给出了基于VAMM的阀损耗计算步骤;其次通过与11电平的MMC详细开关仿真模型对比,验证了VAMM的准确性;之后以某柔直工程换流站作为算例,给出了瞬时功率损耗计算结果,并与使用传统数学解析计算方法得到的结果进行了对比;最后分析了不同工况下阀损耗的分布特性。Present methods for modular multi-level converter(MMC) valve loss estimation are either inaccurate or time consuming. This paper proposed a virtual arm mathematical model(VAMM). Based on this model, the valve loss of MMC was calculated accurately and quickly. This calculation method is valid for various operating conditions, different modulation and voltage balancing strategies. Firstly, basic VAMM structure was presented and the mathematical equations for evaluating valve loss were deduced. Then comparison with 11-level detailed switching model was performed to verify accuracy of VAMM. Finally, the proposed method was applied to valve loss analysis of a real MMC-flexible HVDC system with results showing good agreement with traditional analytic calculation method. The distribution characteristics of valve loss under various operating conditions were also analyzed.

关 键 词：模块化多电平换流器 阀损耗 开关损耗 通态损耗 柔性直流输电 

分 类 号：TM721[电气工程—电力系统及自动化]