摘要
鉴于大容量三相交流异步电机在进行变频-工频切换瞬间存在较大的电网冲击电流,提出一种基于电网电压矢量定向的同步切换控制策略,并采用电力电子开关与交流接触器并联的电路拓扑实现电机变频-工频的同步切换。该控制策略在电网电压同步坐标系下检测到变频器输出线电压空间矢量的相位为30°电角度时触发电力电子开关和交流接触器进行同步切换。实验结果表明该控制策略可精确捕获电机同步切换的最佳时刻实现零相位误差切换,电力电子开关可大幅缩短切换时间,提高了切换控制精度和系统对不同电机及负载的适应性。
There is bigger current impacting on grid when the high-capacity three-phase asynchronous motor switches between VF （Variable Frequency） and PF （Power Frequency）, for which, a strategy of synchronous switching control based on grid-voltage vector orientation is developed. The circuit topology of an electronic power switch connected in parallel with an AC contactor is adopted to realize the synchronous switching between VF and PF. The space vector phase of transducer output line voltage is detected in the grid-voltage synchronous coordinates system,and the electronic power switch and AC contactor are triggered when it is 30 degree for the synchronous switching. Experimental results indicate that,the proposed control strategy captures accurately the best moment for the synchronous switching between VF and PF with zero phase-error,which greatly reduces the switching time,increases the control accuracy and enhances the system adaptability to different motors and loads.
出处
《电力自动化设备》
EI
CSCD
北大核心
2013年第4期82-86,共5页
Electric Power Automation Equipment
基金
江苏省社会发展科技支撑计划项目(BE2010654)~~
关键词
异步电机
电网电压矢量定向
变频-工频同步切换
电力电子开关
电网电压同步坐标系
切换
asynchronous machinery
grid-voltage vector orientation
VF-PF synchronous switching
electronic power switch
grid-voltage synchronous coordinates system
switching
