Abstract: A method for determining an initial rotor position of a permanent magnet synchronous motor (PMSM) includes: generating a plurality of transient currents by applying a plurality of voltages to each phase stator winding of a three phase stator winding of the PMSM; generating three phase current differences according to the plurality of transient currents; determining a first zone in which the initial rotor position of the PMSM is located according to the three phase current differences, wherein angles between 0-360 degrees are divided into a plurality of zones, and the first zone is selected from the plurality of zones; calculating three line current differences according to the three phase current differences; and determining the initial rotor position of the PMSM according to the first zone and the three line current differences.

Abstract: A method for determining an initial rotor position of a permanent magnet synchronous motor (PMSM) includes: generating a plurality of transient currents by applying a plurality of voltages to each phase stator winding of a three phase stator winding of the PMSM; generating three phase current differences according to the plurality of transient currents; determining a first zone in which the initial rotor position of the PMSM is located according to the three phase current differences, wherein angles between 0-360 degrees are divided into a plurality of zones, and the first zone is selected from the plurality of zones; calculating three line current differences according to the three phase current differences; and determining the initial rotor position of the PMSM according to the first zone and the three line current differences.

Abstract: A method for determining zero crossing occurrence in an alternating current (AC) signal with constant frequency of a permanent magnet synchronous motor (PMSM) includes: sampling the AC signal to obtain a plurality of data points; starting to count a number of consecutive data points that have sampled values with a same sign in a detection range, to generate a count value, wherein the consecutive data points are included in the plurality of data points; determining whether the count value is equal to a zero crossing determination value; and in response to the count value being equal to the zero crossing determination value, determining that a zero crossing occurs at a last data point of the consecutive data points.