Abstract
A new position sensorless control method is proposed for interior permanent magnet (IPM) synchronous motor drives at low speed and standstill. The method utilizes the dependence of inductance on rotor position in IPM. To estimate the position error directly, high frequency waves are injected to the motor voltage. The estimation is achieved by using ripple components of the motor current caused by injected waves. The controller directly estimates the error of rotor position, and adjusts the phase angle to the rotor position. At the initial position estimation, it is possible to estimate the initial rotor position including the direction of the magnetization. The basic idea, computer simulation and experimental results are discussed in this paper.
