摘要
如何提高系统起动输出转矩、抑制起动电流是大容量变频调速系统中存在的一个难题。由于半导体器件电流耐量的掣肘,在起动之前通过预励磁方案有效建立起电机内部磁场以减小起动电流、增加起动转矩就成为提高起动性能的行之有效的方法。本文研究了大容量三电平变频调速系统在6000V/2750kW大机组平台上所面临的起动问题,分析了直流预励磁所面临的困难,并采用交流预励磁予以解决。仿真和试验结果表明交流预励磁更利于实现平稳起动。
To increase the starting torque and impress the initial current is a bottleneck in high power adjustable speed drive system. Due to the current restriction of the semiconductor devices, to establish the electromagnetic fields in the induction motor is the key point for starting performance. In this paper, the 6000V/1250kW three-level neutral point clamped （NPC） inverter is applied to the 6000V/2750kW machine sets, and the difficulty of applying DC pre-excitation in this system is studied, then it is solved with AC pre-current. Simulation and experimental results show that the AC pre-excitation is more feasible in this system.
出处
《电工技术学报》
EI
CSCD
北大核心
2007年第11期91-97,共7页
Transactions of China Electrotechnical Society
关键词
直流预励磁
交流预励磁
三电平变频调速系统
起动转矩
异步电机
DC pre-excitation, AC pre-excitation, three-level adjustable speed drive system,starting torque, induction motor
