The invention discloses an iterative phase-locked
limit cycle flux observer, a control method, a control device and a
control system, and the control method comprises the following steps: collecting alpha-beta axis
voltage and current signals of a motor, constructing an IPMSM
mathematical model under an alpha-beta axis, and calculating to obtain a
counter electromotive force vector of the motor; taking the motor back
electromotive force vector as input, acquiring motor
rotor flux linkage information through an iterative phase-locked limit loop
flux linkage observer, and estimating a motor rotating speed and a position
signal according to the motor
rotor flux linkage information; and the rotating speed and the position
signal of the motor are input into a motor closed-
loop control system, so that position-sensorless closed-
loop control of the
permanent magnet synchronous motor is realized. According to the method provided by the invention, the problem of integral drift or phase
lag of a traditional
flux linkage observer can be avoided, the influence of
direct current bias on
flux linkage and position observation precision is effectively suppressed, the dynamic response capability of position sensorless control is remarkably improved, and a position
estimation error generated in a dynamic process is suppressed.