Key points are not available for this paper at this time.
A variable speed drive system is studied which consists of the inverter-fed permanent magnet field synchronous motor without a rotor position sensor and a rotating speed sensor. A method is explained, which determines the rotor position angles at a standstill or at rotating conditions and the speed at several conditions by measuring the instantaneous values of phase voltages and currents. The experimental results obtained by a prototype drive system without a rotor position and a speed sensor are compared with the those obtained by an ordinary DC brushless servo system with a rotor position sensor and a tachogenerator.
Watanabe et al. (Mon,) studied this question.