基于磁链补偿偏差解耦的大功率感应电机直流预励磁起动方法∗

摘要

With the analysis of the problems caused by the high-power induction motor start, including the large impact current, the small output torque, and the damage to the power grid、motor and switch device, a scheme on induction motor DC pre-excitation start based on flux compensation and deviation decoupling was proposed. Before the induction motor start set the excitation current and the torque current by pre-excitation, which established a magnetic field in advance, in the whole dynamic process utilizing flux error compensation to maintain a stable flux, deviation decoupling could be a good guarantee for the excitation and torque control. The simulation results showed that this scheme could made the rotating magnetic chain establish fast and steady, which achieved a good decoupling effect of the whole control system, could effectively reduce the start current, the effect of suppressing peak current was obvious and the output torque responsed quickly.%针对大功率感应电机起动时会出现较大冲击电流，转矩响应较慢，造成电网、电机和开关器件的损害等问题，分析其起动电流过大的主要原因，提出一种基于磁链补偿偏差解耦的感应电机直流预励磁起动方法，通过预励磁对励磁电流和转矩电流进行设定，使电机起动前提前建立励磁磁场，整个动态过程中利用磁链误差补偿来保持磁链的稳定，偏差解耦可以很好地保证对励磁和转矩的控制。仿真结果表明，该方法能够使旋转磁链快速稳定地建立，实现整个控制系统的良好解耦效果，能有效地减小起动电流，对尖峰电流的抑制效果明显，并且转矩有较快的响应速度。