系统强度支撑型可塑变流器(一):暂态电流安全及电磁暂态验证  

System Strength Supported Flexible Converter (I): Transient Current Safety and Electromagnetic Transient Verification

作　　者：杜毅 孙华东 郑超 DU Yi;SUN Huadong;ZHENG Chao(State Key Laboratory of Power Grid Safety and Energy Conservation(China Electric Power Research Institute),Haidian District,Beijing 100192,China)

机构地区：[1]电网安全与节能国家重点实验室(中国电力科学研究院有限公司),北京市海淀区100192

出　　处：《中国电机工程学报》2024年第22期8693-8706,I0001,共15页PROCEEDINGS OF THE CHINESE SOCIETY FOR ELECTRICAL ENGINEERING

基　　金：中国电力科学研究院有限公司自有项目“支撑大电网安全稳定性的新型电力电子设备拓扑结构研究”(XT83-21-018);国家自然科学基金集成项目(U216660003)。

摘　　要：电力电子器件弱过流能力是构网型技术应用的关键制约因素之一。如何在电流限幅约束下既保证变流器自身设备安全性,又充分发挥其电网支撑能力是尚未解决的难题。为此,该文针对系统强度支撑型可塑变流器(system strength supported flexible converter,SSS FC),提出一种基于内电势矢量重塑(potential vector remodeling,PVR)的新型控制框架。首先,在分析SSS FC的暂态过流机理的基础上,给出基于PVR控制的暂态电流抑制新方法,其依据变流器并网端口电压矢量直接改变功率同步控制约束的内电势实现限流,主要包括启动判据、幅相补偿计算以及分相虚拟构建等环节;然后,通过建立SSS FC各电压矢量轨迹与时域暂态电流的理论模型,分析幅相补偿机制对SSS FC暂态特性的改善效果;最后,通过电磁暂态仿真验证各类对称与不对称电网故障下所提方法保证SSS FC本体安全的有效性。The insufficient overcurrent capability of power electronic devices is one of the key factors restricting the application of grid-forming(GFM)voltage source converter(VSC).Ensuring the transient safety of VSCs while maintaining their voltage support capability under current limiting constraints remains an outstanding issue.Therefore,this paper proposes a new control framework based on potential vector remolding(PVR)for a system strength supported flexible converter(SSS FC).The proposed method focuses on analyzing the transient overcurrent mechanism of SSS FC.It introduces a novel approach for transient current suppression through PVR control.This approach limits the current by directly modifying the internal potential of power synchronization control constraints using the voltage vector at the grid-connected port of the converter.The method includes the starting criterion,amplitude-phase compensation calculation,and phase-separated virtual coordinate construction.By utilizing theoretical models of voltage vector trajectory and transient current in the time domain,the effectiveness of amplitude-phase compensation to improve the transient characteristics of SSS FC is analyzed.Finally,electromagnetic transient simulation results show the effectiveness of the proposed method in ensuring the safety of SSS FC under various types of symmetrical and asymmetric grid faults.

关 键 词：系统强度支撑 电压源型变流器 暂态电流抑制 控制策略 内电势矢量重塑 

分 类 号：TM71[电气工程—电力系统及自动化]