Motor rotor position detection method and device, chip and motor control system

The invention provides a motor rotor position detection method and device, a chip and a motor control system. When the motor rotor position detection method is used for detecting the position of a motor, a chip controls a three-phase inverter to output a voltage signal through an injected rotating high-frequency voltage signal, and the chip receives three-phase stator current output to a permanent magnet synchronous motor by the three-phase inverter in the current period. Secondly, band-pass filtering is carried out on the three-phase stator current through a chip according to the electrical angular frequency of the permanent magnet synchronous motor in the last period to obtain a corresponding high-frequency component; thirdly, converting the high-frequency component into a high-frequency synchronous rotating coordinate system through a chip, and performing low-pass filtering to obtain a corresponding low-frequency component; and finally, determining the rotor position of the motor in the current period through a chip according to the low-frequency component and an angle error value determined by the rotor position of the permanent magnet synchronous motor in the previous period, thereby reducing the phase shift caused by filtering, and further reducing the error of the rotor position information.