摘要
针对基于模块化多电平换流器的高压直流输电系统(MMC-HVDC),提出了一种采用分段解析公式计算换流站阀损耗的方法。首先,通过移除最近电平逼近中的取整函数,将桥臂电压转化成理想的光滑波形,根据桥臂电流过零点时刻,对换流阀通态损耗进行分段解析计算。其次,将开关损耗分为必要开关损耗和附加开关损耗。对于前者,通过引入变化率函数进行分段解析计算;对于后者,给出了估算其大小的方法。随后,给出了使用分段解析公式计算MMC-HVDC阀损耗的详细流程。最后,基于时域仿真软件PSCAD/EMTDC下搭建的300 MW/±150kV数字仿真模型,验证了所提方法的有效性。
Based on the modular multilevel converter high voltage direct current（MMC-HVDC） system,a piecewise analytical formula method for valve loss calculation of converters is proposed.Firstly,the arm voltage is transformed into a smooth waveform after removing the nearest integer function.Under this simplification,the conduction losses can be precisely generalized as piecewise analytical formulas right at the instant the arm current crosses zero.Secondly,the switching losses are divided into two parts： the essential switching losses and the additional switching losses.As a result of the introduction of the changing rate function,the essential switching losses are also generalized as piecewise analytical formulas.For the additional switching losses,a method is adopted to estimate the value.The procedures of the proposed methodology for valve loss evaluation of MMC-HVDC are given.Finally,case studies have been carried out based on a 300 MW/±150 kV MMC-HVDC.The results show that the proposed methodology is efficient and effective.
出处
《电力系统自动化》
EI
CSCD
北大核心
2013年第15期109-116,151,共9页
Automation of Electric Power Systems
基金
国家高技术研究发展计划(863计划)资助项目(2012AA051704)~~
关键词
模块化多电平换流器
高压直流输电
阀损耗
分段解析方法
modular multilevel converter
high voltage direct current transmission
valve loss
piecewise analytical method
