摘要
在模块化多电平电压源换流器高压直流输电(MMC-HVDC)系统中,发生在交流输电线路的各类暂态故障或扰动不但会引起与交流系统连接的MMC换流站内上下桥臂不同程度过流、过压现象,也会对对向站的正常运行产生一定程度的负面影响。如何利用MMC换流站内各电气信息实现交流暂态故障或扰动对其运行状态影响程度的评判将是今后MMC-HVDC研究领域的热点问题。针对上述问题,首先分析了交流输电线路暂态故障对站内电压、电流的影响,指出站内各电气信息之间的联系。而后鉴于MMC-HVDC系统阻尼对暂态故障能量传递的抑制作用,考虑故障扰动时站内电压、电流具有变化无规律、频率复杂且扰动特征能量等级低等特点,提出利用Renyi小波包能量熵对交流暂态故障发生时站内电气信息进行特征提取,并根据特征提取结果构建了系统运行状态评判指标集。基于Renyi熵权和灰色关联分析理论,提出了一种双端MMC-HVDC系统运行状态综合评判方法。最后,利用双端31电平MMC-HVDC系统进行了各类交流暂态故障的模拟实验,并基于该方法实现了不同交流暂态故障对MMC-HVDC系统运行状态影响程度的评判,判断结果证明了该方法的有效性。
In MMC-HVDC system, the AC transient faults will bring over-current and overvoltage occurred on arms of rectification and inverter station, as well as abnormal operating state. To evaluate the operating state of MMC-HVDC system is a new issue by using electrical information of MMC when AC transient faults or disturbance occur. To address this issue, this work firstly analyzes the influence of AC transient faults on the electrical signals in MMC in detail, and investigates the relationship of electrical information in MMC. Then, considering system damping, irregular change and complex frequency of the currents and voltages and disturbance feature with low energy in MMC, Renyi wavelet packet energy entropy （RWPEE） is utilized to extract feature of AC transient faults. Based on the feature extraction, the evaluation index set is obtained. In combination of Renyi entropy weight and grey relational analysis, a novel evaluation method is proposed to evaluate operating state of MMC-HVDC system when AC transient faults occur. Finally, 2-terminal 3 l- level MMC-HVDC is used to generate experimental data, and operating state of MMC-HVDC system is evaluated. The experimental results prove the effectiveness of the proposed method.
出处
《仪器仪表学报》
EI
CAS
CSCD
北大核心
2017年第12期3129-3136,共8页
Chinese Journal of Scientific Instrument
基金
国家重点研发计划(2016YFB0900903)
吉林省教育厅"十三五"科学技术研究(JJKH20170098KJ)项目资助
关键词
暂态故障
模块化多电平电压源换流器
高压直流输电
运行状态评判
灰色关联分析
RENYI熵
AC transient faults
modular multilevel converter high voltage direct current （ MMC-HVDC ）
operation state evaluation
grey relational analysis
Renyi entropy
