1results about How to "Eliminates DC bias" patented technology

The invention belongs to the technical field of motor control, and particularly relates to a sensorless back electromotive force observation method for a permanent magnet synchronous motor. The method comprises the following steps: S1, constructing a linear expansion state observer by taking the back electromotive force of a voltage model of the permanent magnet synchronous motor as an expansion state; s2, introducing an internal model item related to the fundamental frequency of the counter electromotive force into the linear expansion state observer to carry out frequency domain design, and obtaining an initial counter electromotive force observer; and S3, introducing a non-linear adaptive item into the initial back electromotive force observer, constructing a weighting function, activating the non-linear adaptive item by using the weighting function, obtaining a final back electromotive force observer, and realizing observation of the back electromotive force. According to the invention, rotor position observation with high dynamic speed and high steady-state precision can be realized.