The invention discloses a PMSM 
rotary transformer zero position initial angle calibration method and calibration 
system. The PMSM 
rotary transformer zero position initial angle calibration method comprises steps of connecting an PMSM, on which a 
rotary transformer is installed, to a driving motor, enabling a motor 
stator of the PMSM to perform three-phase 
short circuit, using the driving motor to drive the PMSM to rotate forward and maintain at a preset rotation speed, using an 
electronic control unit to perform sampling on 
three phase current Ia, Ib and I c and a rotary 
transformer reading phi read at a same moment, using the rotary 
transformer reading phi read to perform Park conversion on 
three phase current Ia, Ib and Ic to obtain current vectors Is,p, calculating a 
vector angle theta p corresponding the 
current vector Is,p, using the driving motor to drive the PMSM to rotate backwards and maintaining the rotation at a preset rotation speed, using the 
electronic control unit to 
record a 
vector angle theta n corresponding to a 
current vector Is,n when the motor is rotated backwards, and calculating that a practical electric rotation angle theta 0 corresponding to the rotary 
transformer reading zero point angle is a zero position initial angle according to a formula theta 0=(thetap+thetan) / 2-180 degree.