基于NPC五电平和H桥混合级联的10 kV静止无功发生器  

A 10 kV static var generator based on a hybrid cascaded five-level NPC and H-bridge converter

作　　者：杜少通[1,2] 吴鹏昆 周娟 朱军[1] 谭兴国[1] 郭向伟[1] DU Shaotong;WU Pengkun;ZHOU Juan;ZHU Jun;TAN Xingguo;GUO Xiangwei(School of Electrical Engineering and Automation,Henan Polytechnic University,Jiaozuo 454003,China;Henan Key Laboratory of Intelligent Detection and Control of Coal Mine Equipment,Jiaozuo 454003,China;School of Electrical Engineering,China University of Mining and Technology,Xuzhou 221116,China)

机构地区：[1]河南理工大学电气工程与自动化学院,河南焦作454003 [2]河南省煤矿装备智能检测与控制重点实验室,河南焦作454003 [3]中国矿业大学电气工程学院,江苏徐州221116

出　　处：《电力系统保护与控制》2025年第6期87-100,共14页Power System Protection and Control

基　　金：国家自然科学基金项目资助(52267018);河南省科技攻关计划项目资助(232102240096)。

摘　　要：针对10 kV电网的级联型静止无功发生器存在器件数量多、耐受电网电压不平衡能力弱的缺点,提出新的混合级联型静止无功发生器(new hybrid cascade static var generator,NHC-SVG)拓扑并建立控制系统。NHC-SVG拓扑由五电平中点嵌位型(neutral-point clamped,NPC)功率单元和H桥级联型功率单元混合级联构成。首先采用最近电平逼近调制与载波相移调制混合实现NHC-SVG的调制。其次,基于调制输出波形建立NPC五电平功率单元中点电位的数学模型,找到中点电位失衡的原因。并采用调节NPC功率单元电平变化时刻相对应的触发角度和注入二倍频谐波电流的方法实现中点电位平衡,进而建立NHC-SVG控制系统。最后以电网电压平衡且直流侧取10%的裕量为设计条件,对10 kV/5 Mvar的NHC-SVG进行算例分析和仿真研究。结果验证了NHC-SVG的有效性,且其补偿额定电流时可耐受电网电压不平衡度大于4。A new hybrid cascaded static var generator(NHC-SVG)topology and corresponding control system are established to address the shortcomings of the cascaded static var generator in the 10 kV power grid,such as large numbers of components and a weak ability to withstand voltage imbalance in the grid.The NHC-SVG topology consists of a five-level neutral point clamped(NPC)power unit and an H-bridge cascaded(CHB)power unit in a hybrid cascade configuration.First,the modulation of the NHC-SVG is achieved by combining the nearest-level approximation modulation with carrier phase-shift modulation.Then,based on the modulated output waveform,a mathematical model of the midpoint potential of the five-level NPC power unit is established to identify the cause of the midpoint potential imbalance.By adjusting the trigger angle corresponding to the level transition time of the NPC power unit and injecting a second harmonic current,midpoint potential balance is achieved,thus establishing the NHC-SVG control system.Finally,taking the voltage balance of the power grid and a 10%margin on the DC side as the design condition,a 10 kV/5 Mvar NHC-SVG is studied and simulated.The results verify the effectiveness of the NHC-SVG and its ability to withstand grid voltage imbalance greater than 4 while compensating for the rated current.

关 键 词：五电平 混合级联 静止无功发生器 电压控制 电压不平衡 

分 类 号：TM7[电气工程—电力系统及自动化]