级联H桥型并网逆变器的低电压穿越控制研究  

Research on the Low Voltage Ride Through Control of Cascaded H-bridge Grid-connected Inverter

作　　者：林珊 赵涛[2] 邱富修 LIN Shan;ZHAO Tao;QIU Fu-xiu(Guangzhou Metro Design and Research Institute Co.,Lid.,Guangzhou510010,China;Qingdao University,Qingdao 266071,China)

机构地区：[1]广州地铁设计研究院股份有限公司,广东广州510010 [2]青岛大学,山东青岛266071

出　　处：《电力电子技术》2025年第3期14-18,共5页Power Electronics

基　　金：国家自然科学基金青年项目(52307209);山东省自然科学基金青年项目(ZR2022QE057)。

摘　　要：三相级联H桥(CHB)光伏并网逆变器在低电压穿越(LVRT)过程中存在有功功率回流问题,可能导致系统无平衡工作点,无法满足并网标准。现有方法在特定运行条件下可以解决这一问题,然而在相间短路故障时仍存在较大的有功功率回流区域。因此,本文提出了一种提高CHB光伏逆变器LVRT性能的谐波补偿策略。具体而言,将非故障相的调制电压扩展为三相对称电压,然后计算其最大和最小值谐波电压,将其作为零序电压补偿给三相CHB光伏逆变器。最后,通过低压小功率样机的实验结果验证了所提策略的有效性和可行性。Three-phase cascadedH-bridge(CHB)photovoltaic grid-connected inverter suffers from active power back-flow during low voltage ride through(LVRT),which may cause the system to have an unbalanced operating point and can not meet the grid connection standards.The existing methods can solve this problem under specific operating con-ditions,however,there still exists a large active power backflow area during inter-phase short-circuit faults.Therefore,a harmonic compensation strategy is proposed to improve the LVRT performance of CHBphotovoltaic inverters.Specif-ically,the modulation voltage of the non-fault phase is extended to a three-phase symmetrical voltage,and then its maximum and minimum harmonic voltages are calculated,which are used as zero-sequence voltage compensation to the three-phase CHBphotovoltaic inverter.Finally,the effectiveness and feasibility of the proposed strategy are verified through experimental results of a low-voltage low-power prototype.

关 键 词：并网逆变器 光伏 低电压穿越 

分 类 号：TM464[电气工程—电器]