具有中点电压平衡与零序电流抑制的T型三电平逆变器供电六相PMSM-DTC  

Six-Phase PMSM-DTC Control with Midpoint Voltage Balance and Zero-Sequence Current Suppression Powered by T-Type Three-Level Inverter

作　　者：黄德猛 周扬忠 屈艾文[1] 禹春敏 Huang Demeng;Zhou Yangzhong;Qu Aiwen;Yu Chunmin(Fujian Key Laboratory of New Energy Generation and Power Conversion,Fuzhou University,Fuzhou 350116,China)

机构地区：[1]福州大学福建省新能源发电与电能变换重点实验室,福州350116

出　　处：《电工技术学报》2024年第20期6371-6385,共15页Transactions of China Electrotechnical Society

基　　金：福建省自然科学基金重点资助项目-数控机床电主轴五自由度磁悬浮双定子无轴承磁通切换电机驱动控制关键技术研究(2021J02023)。

摘　　要：在三电平六相电机驱动系统中,存在中点电压不平衡及零序电流导致定子电流畸变等问题。为此,该文针对T型三电平逆变器供电的六相永磁同步电机,提出一种具有中点电压平衡与零序电流抑制功能的直接转矩控制(DTC)策略。为实现DTC的快速构建,该策略基于两电平三相电机DTC结构,利用精简后的开关状态,在六相绕组轴线上分别合成满足控制要求的4个电压矢量,然后通过两个滞环比较器结合简单的扇区划分,确定最优电压矢量所在轴线,同时构建中点电压与零序电流控制平面,并对系统在控制平面所处扇区进行判断。在此基础上,根据最优电压矢量所在绕组的相电流iy的极性,实现最优电压矢量的选择,并进一步构建DTC最优开关矢量表。最后,通过实验结果验证了所提控制策略的可行性和有效性。The three-level multi-phase drive system combines the advantages of multi-phase motors and three-level inverters.However,midpoint voltage imbalance and excessive zero-sequence current exist.Midpoint voltage imbalance can lead to output voltage distortion,while excessive zero-sequence current can cause distortion of the stator current and increased losses.Direct torque control(DTC)requires minimal dependence on motor parameters,with a simple algorithm and strong adaptability to load changes.However,research based on DTC theory is still relatively rare.The symmetrical six-phase permanent magnet synchronous motor(PMSM)has high efficiency,a fast response rate among multi-phase motors,and superior fault tolerance.Therefore,this paper proposes a DTC strategy for a symmetrical six-phase PMSM powered by a T-type three-level inverter to balance midpoint voltage and suppress zero-sequence current.Firstly,by using a spatial vector projection method to remove the redundant switching states in the switching state,the switching states are reduced from 729 to 189.Secondly,based on the three-phase PMSM-DTC structure powered by the two-level inverter,the scheme synthesizes four voltage vectors to meet the control requirements on the six-phase axis using the simplified switching state.In addition,by combining flux linkage and torque hysteresis comparator with simple sector division,the axis of the optimal voltage vector is determined,and the midpoint voltage and zero-sequence current control plane are constructed.The sector where the system is located in the control plane is judged.According to the polarity of the winding phase current iy of the optimal voltage vector,the optimal voltage vector selection is realized,and the optimal switch vector table of DTC is further constructed.Steady-state comparative experiments are conducted.Compared to the traditional approach,the proposed method maintains a balanced midpoint voltage,effectively suppresses zero-sequence current to approximately 0 A,and significantly sinusoidalize phase curr

关 键 词：T型三电平逆变器 六相永磁同步电机 直接转矩控制 中点电压平衡 零序电流抑制 

分 类 号：TM301.2[电气工程—电机]