中频三相四桥臂逆变器控制策略不平衡负载状态相量模型分析  

Analysis on Control Strategies for Unsymmetrical State of Medium Frequency Three Phase Four Leg Inverter Based on Vector Model

作　　者：陈轶涵 郭鸿浩 陈杰[2] 王成超 马海啸[1] Chen Yihan;Guo Honghao;Chen Jie;Wang Chengchao;Ma Haixiao(College of Automation Nanjing University of Posts & Telecommunications Nanjing 210023 China;College of Automation Engineering Nanjing University of Aeronautics & AstronauticsNanjing 211106 China)

机构地区：[1]南京邮电大学自动化学院,南京210023 [2]南京航空航天大学自动化学院,南京211106

出　　处：《电工技术学报》2019年第9期1912-1923,共12页Transactions of China Electrotechnical Society

基　　金：江苏省自然科学基金青年项目(BK20160894);国家自然科学基金项目(51507083)资助

摘　　要：三相四桥臂逆变器具备不平衡负载工作能力与三相解耦控制功能,但是在中频场合基于模拟控制的四桥臂控制策略较为复杂。该文基于第四桥臂开环、闭环控制方法,结合三次谐波注入控制策略,采用建立主电路电压、电流以及控制环路信号相量模型的方式,通过分析和对比不同控制策略在不平衡负载下的工作特性,得到第四桥臂控制方法与电路参数的关系,总结控制策略设计依据。证明基于三相电流环输出控制信号合成的三次谐波能够在不平衡负载状态实现对第四桥臂大部分零序分量的补偿。在此基础上,提出一种结合三次谐波注入与中线电流闭环的控制方法,该方法在保证直流电压利用率的同时,进一步提高了不平衡负载下三相输出波形质量。该文还通过仿真和实验验证了理论分析的正确性。Three phase four leg inverter has ability to work under unsymmetrical load, also has three phase decoupling character. However, control strategy based on analog circuit in middle-frequency applications is complex. In this thesis, based on control strategies,such as open loop, closed loop and three harmonic injection of fourth leg, vector model consists of voltage, current signals of main and control circuit also can be established. Relationship of control strategies of fourth leg and circuit parameters can be obtained by comparing control characteristics of fourth leg control strategies. In conclusion, it can be proved that third harmonic signal generated by output signals of three phase current loops can compensate most of zero-sequence component of fourth leg under unsymmetrical load. On this basis, in this thesis, the control strategy combines both third harmonic signal injection and closed loop control of fourth leg is proposed, it can not only guarantee the DC voltage utilization, but also improve the quality of output voltage under unsymmetrical load. Simulation and experiment results prove theoretical analysis is correct.

关 键 词：三相四桥臂 相量模型 零序电流 三次谐波注入 

分 类 号：TM614[电气工程—电力系统及自动化] TM76