Patent ID: 7342378
Filing Date: 2008-03-11
Classification: H02P

Abstract:
1. A motor driving apparatus including an inverter for driving a synchronous motor as a load by inputting a DC and converting it to a three-phase AC by power semiconductor switching devices, a driving circuit for driving said power semiconductor switching devices of said inverter and a motor controller for outputting an inverter driving signal to said driving circuit, said motor driving apparatus comprising: a first pulse generator for generating a signal that brings said power semiconductor switching devices of said inverter to an OFF level; a second pulse generator for inputting the signal of said first pulse generator and generating a signal after the passage of a predetermined wait time; an induced voltage detector for inputting the signal of said second pulse generator and detecting a terminal voltage of said synchronous motor as said load; a phase calculator for inputting an output of said induced voltage detector and calculating a phase of said induced voltage; a rotating direction estimator for outputting a rotating direction estimation value of said motor from the output of said phase calculator; and a rotor position calculator for inputting the phase of said induced voltage and said rotating direction estimation value, and outputting the rotor position estimation value to said motor controller.