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### 提高弱电网下LCL型并网逆变器稳定性的改进电网电压前馈策略 *

1. 1. 西安理工大学自动化与信息工程学院 西安 710048
2. 国网昌吉换流站 昌吉 831100
• 收稿日期:2019-05-05 出版日期:2019-06-25 发布日期:2019-10-25
• 作者简介:于文倩,女,1995年生,硕士研究生,主要研究方向为有源电力滤波器的应用设计。 E-mail： 736481556@qq.com。|同向前,男,1961年生,教授,博士研究生导师,主要研究方向为电力电子技术在电力系统中的应用。E-mail： lstong@mail.xaut.edu.cn
• 基金资助:
*国家自然科学基金资助项目(51677151)

### An Improved Grid Voltage Feedforward Strategy for LCL-type Grid-connected Inverters in Weak Grid

YU Wenqian1,TONG Xiangqian1,YAN Cong1,JIAO Pan2

1. 1. Faculty of Automation and Information Engineering, Xi’an University of Technology, Xi’an 710048 China;
2. State Grid Changji Converter Station, Changji 831100 China
• Received:2019-05-05 Online:2019-06-25 Published:2019-10-25

Abstract:

Grid-connected inverters often use grid voltage feedforward control to improve the suppression capability and startup performance of the system. When the grid behaves a weak grid, the direct proportional feedforward control of the grid voltage will weaken the stability margin of the grid-connected inverter control system. Based on the comparative analysis of the open-loop frequency characteristics of no feedforward and direct proportional feedforward control under weak grids, an improved feedforward scheme is proposed with a lag transfer function for frequency selective in the voltage feedforward channel. Thus the system stability margin improves obviously. Finally, the verification is carried out on a set of LCL-type grid-connected inverter experimental platform. The experimental results demonstrate that the adaptability of improved voltage feedforward strategy under weak grid is more stronger.