摘要
多电平有源中点钳位(ANPC)逆变器具有功率器件电压应力小、电流谐波低和器件损耗可调控等优点,被广泛应用于工业驱动中。针对四电平ANPC(4L-ANPC)逆变器的控制与调制研究相对较少,现有的调制方案实现复杂,中点电压(NPV)控制难度较大。因此,该文针对三相4L-ANPC逆变器,提出一种改进的有限集模型预测电流控制(FS-MPCC)算法,避免了复杂的调制过程。首先,使用仅包含电流误差的代价函数对位于六边形顶点的6个大电压矢量进行寻优;其次,对参与第一步寻优的大矢量划分扇区,使用包含电流误差和电容电压误差的代价函数对最优大矢量所在扇区的所有电压矢量滚动寻优,得到目标电压矢量并作用于逆变器;最后,仿真和实验结果表明,与传统的FS-MPCC相比,所提方法在降低系统计算负担的同时,还具有较好的控制性能和电容电压平衡能力。
Multi-level inverters can generate high-quality stepped AC voltage with advantages such as low harmonic content,switch state redundancy,and small common mode voltage,which is suitable for various power applications.Compared to cascaded H-bridge multi-level inverters,the active neutral point clamped(ANPC)inverter uses few power semiconductors without multiple independent DC sources and is cost-effective for low to medium-voltage applications.Furthermore,compared to diode-based passive,neutral point clamped(NPC)inverters,the ANPC inverter can better distribute power losses among power semiconductors,resulting in higher reliability.To effectively control a four-level ANPC(4L-ANPC)inverter and avoid using complex modulation strategies,this paper proposes an improved finite set model predictive current control(FS-MPCC)algorithm that adopts a two-step voltage vector selection mechanism to achieve excellent control performance and ensure capacitor voltage balance.Firstly,the improved FS-MPCC evaluates the six large voltage vectors(LVVs)at the outer layer of the four-level voltage vector hexagon.The LVV that minimizes the cost function containing only current errors is selected as the optimal LVV.The LVV does not affect the neutral point(NP)capacitor voltage and cannot suppress neutral point voltage(NPV)fluctuations.In addition,the spatial position of the optimal LVV may not be closest to the reference voltage vector.Directly applying the optimal LVV can cause increased harmonic currents and reduced control system stability.Therefore,in the second stage,the optimal LVV obtained in the first stage is used as the central voltage vector,and all voltage vectors within a 60°range are optimized.The second-stage voltage vectors(13 voltage vectors)include medium voltage vectors(MVVs)and small voltage vectors(SVVs)that can affect the neutral point potential.Each candidate voltage vector is substituted into a cost function with current and capacitor voltage errors for rolling optimization.The final target voltage vector is obtain
作者
向超群
杜京润
Zhang Xinan
席振
丁颢
Xiang Chaoqun;Du Jingrun;Zhang Xinan;Xi Zhen;Ding Hao(School of Traffic and Transportation Engineering Central South University,Changsha 410075 China;Department of Electrical and Electronic Engineering School of Engineering The University of Western Australia,Crawley WA6009 Australia)
出处
《电工技术学报》
EI
CSCD
北大核心
2024年第18期5826-5838,共13页
Transactions of China Electrotechnical Society
基金
国家自然科学基金资助项目(52002409)。
关键词
四电平
有源中点钳位逆变器
有限集模型预测电流控制
电容电压平衡
代价函数
Four-level
active neutral point clamped inverter
finite set model predictive current control
capacitor voltage balance
cost function
