Initial rotor position estimation for surface permanent magnet synchronous motor

This paper presents an estimation method of initial rotor position for a surface permanent magnet synchronous motor. The principle of the estimation is based on the variation of the current response caused by the magnetic saturation of the stator core when the voltage vector is applied to the motor. This method can be performed without motor parameters and the additional hardware. A decision method of the optimum voltage vector applied to the motor is also proposed to accurately implement the estimation. Experimental results show that the initial rotor position can be estimated without rotating the rotor by using the optimum voltage vector.