Method for observing speed of permanent magnet motor

Abstract

The invention discloses a method for observing the speed of a permanent magnet motor, and relates to the field of speed observation and speed control for motors. The method comprises the steps of combining the rotor position acquired by an absolute type encoder with three parts of a designed kalman observer, observing the rotating speed of a rotor and a load torque of the motor, and using the observed rotating speed as feedback signals of a rotating speed ring of a permanent magnet synchronous motor control system; regarding the suddenly changed load torque of a permanent magnet synchronous motor as a system disturbance variable, using the motor load torque observed by the constructed kalman observer as feed-forward signals of a current loop, and constructing a feed-forward control system; acquiring the switching sequence of an inverter through a current controller and a space vector pulse width modulation method, then acquiring three-phase voltage inputting into the permanent magnet synchronous motor, and finally enabling the permanent magnet motor to rotate by a certain rotating speed. The method disclosed by the invention adopts the load torque acquired by the adaptive kalman observer, thereby being capable of timely reflecting load variation conditions of the system, carrying out feed-forward control on the estimated load torque, and being capable of improving an accurate tracking ability for the rotating speed.

Description

technical field [0001] The invention relates to the fields of motor speed observation and speed control, in particular to a permanent magnet motor speed observation method. Background technique [0002] For the permanent magnet synchronous motor (PMSM) servo system, the rotor position and speed of the motor are essential feedback quantities in the closed-loop control system. In traditional position measurement methods, position signals are mostly obtained through optical encoders. Optical encoders are generally divided into incremental encoders, absolute encoders and hybrid encoders. Among them, the absolute encoder can directly obtain the binary code of the absolute position of the rotor, and each position has a unique binary code. Compared with other encoders, absolute encoders have obvious advantages in anti-interference ability and positioning ability, so they have been widely used in high-precision mechanical equipment and other places. [0003] Due to quantization n...

AI Technical Summary

Problems solved by technology

However, because the traditional Kalman filtering algorithm needs to conduct multiple experiments on the noise parameters in order to have a good observation effect, this will undoubtedly reduce the work efficiency. Therefore, it is urgent to find a method to solve or replace this problem

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