一种带自学习功能的DC-BANK系统投切控制策略研究

Design of switch controller strategy of DC-BANK

电网"晃电"易导致变频器低压跳闸,给连续型生产企业造成严重影响。针对传统DC-BANK系统"晃电"检测智能化程序低,固定压差投切方案不能充分减小投切动作对电机正常工作的影响,设计一种含电网电能质量监测、带自学习功能的投切控制策略。仿真结果表明,新型带自学习功能的DC-BANK系统投切控制器不再局限于单纯依靠对母线电压中东的检测,对电压暂降反应更快。基于该控制器对于母线电压跌落的预判和近压投切能减小固定压差投切对于电机系统正常工作的影响,有利于系统的持续稳定工作,适用于对电能质量要求更高的变频器系统抗"晃电"改造。

VFD trips when voltage sags occur, which brings serious influence to continuous production. With a low inteUigentialize degree on flicker detection, fixed voltage switch strategy is unable to minimize the impact the switching movement has on the working state of the motor. A new switch strategy with grid power quality detection and self-learning function is designed. Simulation shows that with higher reaction speed, the new switch strategy of DC-BANK system is no longer limited to busbar voltage detection. Based on the previewing of voltage sag on busbar and switching with a closer voltage, the new sw^tch strategy creates less impact on the VFD-motor system and is able to meet the demands of anti-flicker circuit transformation of VFD in high quality required situation.