电网技术2025，Vol.49Issue(7)：2989-2998,中插86-中插89,14.DOI:10.13335/j.1000-3673.pst.2024.0724
基于dq坐标变换的换流器差动保护方法
Differential Protection Method for Converters Based on dq Transformation
摘要
Abstract
A differential protection method for converters based on dq transformation is proposed to address the problem of existing converter protections having insufficient sensitivity and not even recognizing all types of faults.This method synchronously obtains the AC side currents of the converter in two ways,namely direct measurement and indirect calculation,where the relationship between the bridge arm currents and the AC side currents of the converter derives the calculated currents.Then,the currents obtained in both ways are transformed from three-phase currents to the dq-axis current.Furthermore,differential currents are calculated using the dq-axis current,and protection criteria for d-axis and q-axis are constructed,respectively.Moreover,the differential criteria of d-axis and q-axis are set to an OR logical relationship.A complete protection scheme,including return logic,has been designed based on this.The proposed method can reflect all types of faults in the entire converter area and improve protection sensitivity by dq-axis current that appears in direct current form.A simulation model of an AC-DC hybrid grid with four converter stations is built in PSCAD.The performance of the proposed protection scheme is verified and compared with existing differential protections.The simulation results show that the proposed protection can comprehensively reflect the faults in the converter area than pole current differential protection,and it can withstand 1000 Ω transition resistance,which proves that the proposed protection possesses a higher sensitivity than differential protection of the bridge phase unit.关键词
交直流混联电网/换流器保护/差动保护/dq变换Key words
AC-DC hybrid grids/converter protection/current differential protection/dq coordinate transformation分类
信息技术与安全科学引用本文复制引用
杜庆秀,刘益青,高伟聪,颜迪,邹贵彬..基于dq坐标变换的换流器差动保护方法[J].电网技术,2025,49(7):2989-2998,中插86-中插89,14.基金项目
国家自然科学基金项目(52077124) （52077124）
山东省自然科学基金项目(ZR2022ME097).Project Supported by National Natural Science Foundation of China(NSFC)(52077124) （ZR2022ME097）
Shandong Provincial Natural Science Foundation,China(ZR2022ME097). （ZR2022ME097）
