一种能消除直流偏置和稳态误差的电压型磁链观测器

电压型磁链观测器由于物理概念清晰、简单易用而备受关注.然而它固有的初值误差和直流偏置问题,使用已有的低通滤波器(LPF)等方法很难彻底解决,而且会带来稳态误差.本文在已有方法的基础上,提出了一种使用低通滤波器和高通滤波器(HPF)串联代替纯积分求解定子磁链的新方法,更有效地消除了初值误差和直流偏置的影响,并利用时间相量分析的方法,推出稳态误差的补偿公式,实现了磁链观测零偏置和稳态无误差.该方法简单明了,易于在数字系统中实现.仿真和试验结果都显示,直接转矩控制的低速性能有了显著提高,这也证明了新观测器的有效性.

Method for elimination of DC offset and steady state error for voltage module flux observer

The flux observer based on voltage has been obtained more attention for its clear concept and simple usage.However,the inherent initial value error and DC offset problem can not be completely removed using the existing low pass filter(LPF) method.Besides,LPF also brings steady state error.In the proposed method,the pure integrator is replaced by low pass filter and high pass filter(HPF) in series to eliminate the initial value error and DC offset effect,and the steady state error can be compensated completely.So the flux has no amplitude and phase error.The compensation formula is derived with time phasor method.The novel observer is simple and easier to apply to digital system.Both simulation and experimental results show that the induction motor performance in low speed region has been improved remarkably.This also verifies the effectiveness of the novel observer.