基于超级电容型MMC系统的电铁负序补偿控制策略  

Negative sequence compensation control strategy for electrified railways with super-capacitor integrated MMC

作　　者：罗忠游 赵普志 段玉 秦艳辉 陈天舒 LUO Zhongyou;ZHAO Puzhi;DUAN Yu;QIN Yanhui;CHEN Tianshu(Electric Power Research Institute,State Grid Xinjiang Electric Power Co.,Ltd.,Urumqi,Xinjiang 830011,China;State Grid Xinjiang Electric Power Co.,Ltd.,Urumqi,Xinjiang 830063,China;School of Electrical Engineering,Southwest Jiaotong University,Chengdu,Sichuan 611756,China)

机构地区：[1]国网新疆电力有限公司电力科学研究院,新疆乌鲁木齐830011 [2]国网新疆电力有限公司,新疆乌鲁木齐830063 [3]西南交通大学电气工程学院,四川成都611756

出　　处：《机车电传动》2023年第4期98-106,共9页Electric Drive for Locomotives

基　　金：国网新疆电力有限公司科技项目(5230DK220009);国家自然科学基金项目(52277126)。

摘　　要：为了解决单相电铁负荷在三相电网中引起以负序为主的电能质量问题,文章以超级电容储能型模块化多电平变流器(SC-MMC)系统为对象,以变流器精确补偿负序电流与储能高效利用再生制动能量为调控手段,提出一种适用电铁负序补偿的控制策略,在MMC的子模块中分散接入超级电容储能装置,协调MMC与储能装置共同补偿负序,提高系统的可靠性与灵活性。首先,以主电路拓扑结构和负序补偿原理为基础,分析储能型模块化多电平系统的工作原理;然后,基于单相等效电路构建系统数学模型并结合机车负荷特性与超级电容荷电状态(SOC)划分充电、放电、平衡工作模式;最后,提出分层协调控制策略,其中上层能量管理判断工作模式并以相关国标限值为约束计算各端口参考功率,下层端口电流控制实现各端口的功率跟踪并协调不同工作模式间的动态切换。案例分析表明:SC-MMC系统在不同的机车负荷水平和超级电容SOC下能够有效实现电网负序的补偿,并协调控制超级电容与MMC参与补偿。In order to solve the power quality issue caused by dominant negative sequences,which result from single-phase loads of electrified railways in the three-phase grids,this paper presented a control strategy of compensation for negative sequences particularly suitable for electrified railways,taking the super-capacitor integrated modular multilevel converter(SC-MMC)system as the object,and leveraging precise compensation of negative sequence current by converters and efficient utilization of regenerative braking energy through energy storage facilities as the regulation means.Aimed to improve system reliability and flexibility,the MMC sub-modules were connected with super-capacitor storage devices in a decentralized pattern,to coordinate the MMC and energy storage devices for joint negative sequence compensation.This study began with an analysis of the working theory of the energy storage modular multilevel system,based on the main circuit topology and negative sequence compensation principle.Then,a system mathematical model was constructed based on a single-phase equivalent circuit and working modes were divided into charging,discharging,and balancing,taking into account the locomotive load characteristics and super-capacitor state of charge(SOC).Finally,a hierarchical coordinated control strategy was proposed,among which energy management is designed at the upper layer to identify working modes and calculate reference power for each port within the limits specified in relevant national standards,while port current control was designed at the lower layer to enable power tracking for each port and dynamic switching coordination between different operating modes.The case study shows the effectiveness of the SC-MMC system in compensating for negative sequences in the grid under different locomotive load levels and super-capacitor SOC scenarios,and coordinated control of the super-capacitor and MMC to contribute to compensation.

关 键 词：超级电容储能系统 模块化多电平变流器 电能质量 分层协调控制 

分 类 号：U223.5[交通运输工程—道路与铁道工程]