火电厂辅机变频器低电压穿越技术在电网应用研究  

Research on Application of Low Voltage Ride Through Technology of Auxiliary Equipment Inverter of Thermal Power Plant in Power Grid

作　　者：张志轩 由新红 马欢 赵康 周宁 李常刚[2] ZHANG Zhixuan;YOU Xinhong;MA Huan;ZHAO Kang;ZHOU Ning;LI Changgang(State Grid Shandong Electric Power Research Institute,Jinan 250003,China;School of Electrical Engineering,Shandong University,Jinan 250061,China)

机构地区：[1]国网山东省电力公司电力科学研究院,山东济南250003 [2]山东大学电气工程学院,山东济南250061

出　　处：《山东电力技术》2020年第12期32-36,共5页Shandong Electric Power

基　　金：国家自然科学基金项目(51407107);国家电网公司科技项目“适用于大电网分析的电力电子设备/集群多场景建模技术研究”(5100-202055388A-0-0-00)。

摘　　要：为防止交直流混联电网频率、电压异常等情况下引发连锁性故障,开展Ⅰ类辅机低电压穿越改造,保证电厂一类辅机在20%、60%和90%额定电压下具备低电压穿越能力。为提高低电压穿越设备在电压支撑过程中的适应性,以二极管为整流桥原件,建立了三相不控整流桥和Boost升压电路。针对现场试验中部分工况下低电压穿越装置的跳闸现象,将整流电路和Boost升压控制系统参数改进调节,并附加缓冲电路。MATLAB仿真结果表明,在不同的工况下,系数调节后的电路具备更低的震荡波峰。To prevent cascading failures caused by abnormal frequency and voltage of AC/DC hybrid power grids,carry out the low voltage ride through transformation of type I auxiliary equipment to ensure that the power plant auxiliary equipment has the ability of low voltage ride through under 20%,60%and 90%of the rated voltage.In order to improve the adaptability of the low voltage ride through equipment in the voltage support process,a three-phase uncontrolled rectifier bridge and a boost circuit are built with diodes as the original rectifier bridge.In view of the tripping of the low voltage ride through device under some working conditions in the field test,the parameters of the rectifier circuit and the boost control system were improved and adjusted,and a buffer circuit was added.MATLAB simulation results show that,under different working conditions,the circuit after coefficient adjustment has a lower oscillation peak.

关 键 词：变频器 低电压穿越 三相整流桥 缓冲电路 

分 类 号：TM461[电气工程—电器]