基于磁链控制的异步电机V/F控制系统直流预励磁起动方法

DC Pre-Excitation Start Strategy Based on the Flux Control for V/F Controlled Induction Motor Drive System

结合常规的直流预励磁方法提出了一种适用于变频器-异步电机VVVF控制系统的起动方法,以解决中大容量通用变频调速系统起动电流过大的问题。该方法的本质是电机磁链控制,以直流预励磁建立的磁链为初始状态,然后在起动过程中根据定子电流的无功分量反馈值修正输出电压,维持稳定的圆形旋转磁链。这种方法解决了常规直流预励磁方法有效作用时间短的问题,能提高电流对称性与转矩的稳定性,对整个起动过程中尖峰电流抑制效果明显,且实验效果在380V/315kW异步电机上得到验证。

Based on traditional DC pre-excitation, the paper proposes a start strategy for V/F controlled induction motor drive system to depress the inrush current in high/middle power adjustable speed drives start-up process. During the start-up process the output voltage is adjusted according to the fluctuation of feedback reactive current. The flux whose initial value is built by DC pre-excitation is kept in a circle track during the whole start process. Compared to traditional DC pre-excitation, the proposed method is capable of depressing the torque jerk and inrush current in the whole start process and improve the current symmetry. The experiments on the 315kW ASD systems validated the effectiveness of the proposed design methods.