Method for detecting position of rotor of electrically excited synchronous motor without sensor in whole process based on excitation current pulse response

The invention relates to a method for detecting the position of a rotor of an electrically excited synchronous motor without a sensor in a whole process based on excitation current pulse response, belonging to the field of control of motors. The problem that injection of a high-frequency signal from a stator side is limited by a frequency converter control method can be solved. The method disclosed by the invention comprises the following steps of: (1), adopting a triggering strategy of an excitation bridge circuit, such that a pulse signal having a fixed frequency is superposed on excitation current on the basis of a direct-current component, wherein the fixed frequency of the pulse signal is fh; (2), acquiring three-phase counter electromotive force line voltage of the motor, and extracting the pulse signal, the frequency of which is fh; (3), extracting envelope lines eAB_h, eBC_h and eCA_h of three-phase high-frequency signal induced electromotive force of the pulse signal, the frequency of which is fh; an