SENSORLESS MOTOR ROTOR ANGLE CORRECTION METHOD AND SYSTEM

A sensorless motor rotor angle correction method includes: outputting a direct-axis pulse voltage to generate a direct-axis current and a quadrature-axis current; determining whether an angle difference is zero; outputting a positive direct-axis excitation voltage when the angle difference is zero, and recording an excitation time required to reach a predetermined positive current value; outputting a negative direct-axis excitation voltage, so that the direct-axis current returns to an initial current value; outputting a negative direct-axis excitation voltage for the excitation time to obtain a maximum negative current value; outputting a positive excitation voltage, so that the direct-axis current returns to the initial current value; correcting an orientation of a synchronous rotation coordinate axis if the maximum negative current value is greater than the predetermined positive current value.