四端口电力电子变压器高压交流端口的低电压穿越功能  

Low voltage ride through function for the high voltage AC ports of four-port power electronic transformers

作　　者：聂浩哲 沈瑜[1] 赵争鸣[1] 文武松 袁立强[1] NIE Haozhe;SHEN Yu;ZHAO Zhengming;WEN Wusong;YUAN Liqiang(State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment,Department of Electrical Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学电机工程与应用电子技术系,电力系统及发电设备安全控制和仿真国家重点实验室,北京100084

出　　处：《清华大学学报（自然科学版）》2021年第10期1097-1105,共9页Journal of Tsinghua University(Science and Technology)

基　　金：国家重点研发计划(2017YFB0903203)。

摘　　要：随着电力电子变压器在电力系统中的应用,其运行安全性和稳定性也开始受到广泛的关注和研究。并网点短路故障引起的电力电子变压器交流端口电压跌落问题会造成电力系统严重失稳,并使电网的故障恢复困难。针对一种模块化四端口电力电子变压器,该文从能量的角度分析了其高压交流端口发生电压跌落问题时的失稳机理。为了维持电力电子变压器在故障期间的安全稳定运行,提出了一种低电压穿越控制方案,通过切换电力电子变压器的功率平衡端口与端口控制策略,实现了电力电子变压器的低电压穿越功能。基于DSIM仿真平台对所提的低电压穿越控制方案进行验证,证明了该方案能够有效提高电力电子变压器的运行安全性和稳定性,实现了真正意义上的多端口电力电子设备的低电压穿越功能。The widespread use of power electronic transformers in power systems has led to more research on their operational safety and stability. The voltage sag in the alternating current(AC) port of the power electronic transformer caused by a short circuit fault of the grid connection point can lead to serious instabilities which can slow the power grid recovery. The instability mechanism of the high voltage AC port of a modular four-port power electronic transformer is analyzed in terms of the energy characteristics when a voltage sag fault occurs. Then, a low voltage ride through control scheme is given to maintain safe, stable operation of the power electronic transformer during the fault. This scheme provides a low voltage ride through function by switching the power balance port and the power electronic transformer control strategy. Finally, this low voltage ride through control scheme is verified using DSIM simulations which shows that the scheme effectively improves the safety and stability of the power electronic transformer and provides low voltage ride through in multi-port power electronic equipment.

关 键 词：电力电子变压器 低电压穿越 功率平衡 直流母线稳压控制 DSIM电力电子仿真 

分 类 号：TM743[电气工程—电力系统及自动化]