This paper deals with position vector control of Two Phase Induction Machine (TPIM). Indirect Rotor-Field Oriented Control -IRFOC was used as a vector control scheme. Each phase of induction motor is fed independently by single phase full-bridge inverter. A general model of control system of the two-phase induction machine including a position loop is proposed in the paper. The virtual high frequency injection method for position estimation without using sensor of the position is also proposed in the paper. A computer simulation and experimental verification of the position vector control of two-phase induction motor drive is realized and results are presented. I. [NTRODUCTION Two-phase induction motors (T PIMs) are one of widely used motors. To achieve a variable speed operation a power electronics inverter can be used. Indirect Rotor-Field Oriented Control (IRFOC) is modern technique for high perfonnance control of the PWM inverter fed TP[M. The cost reduction of the semiconductor switches and efficient use of the energy, even for low-power application, has stimulated the investigation of different two-phase motor drive schemes [1 .1 -[3]. [n these schemes the single-phase motor drive, wIthout startup and running capacitor, is treated as an asymmetric two-phase machine. This paper investigates the use of the scheme in Fig. 1 to feed independently each phase of TPIM. The field oriented strategy is based on the papers [4 ]-[7] and it will be described in the next section. The importance of the virtual high frequency injection method is in injecting of the high frequency signal in the model of the machine, not in the real motor. 8* Fig. 1 Block diagram of position vector control algorithm II. POSITION VECTOR CONTROL Model of TP[M is explained in [8]-[[ 0] and therefore the motor and control algorithm will not be described in great detail in this paper. The proposed control algorithm scheme of IRFOC is depicted in Fig. 1. Where: Wsl = W,-W is the slip frequency, Ws = db/dt is the synchronous frequency brfis the position of the rotor flux vector. Then, isd/ controls the rotor flux and i,q/ controls the electromagnetic torque. As an example, Fig. [ shows the block diagram of [RFOC which has been adapted for the two phase machine. [n this diagram Te * and !{Jr * represents the reference electromagnetic torque and amplitude of the rotor flux, respectively.The d o r t block performs the coordinate transformation from the reference frame aligned along with the rotor-flux vector to the stationary reference frame. Furthermore, is/ and ist represents the reference currents supplied to the PI stator current controllers which must be imposed on the machine windings. [t can be seen that the two current controllers provide control voltages Vsd and Vsq. These voltages are supplemented by decoupling voltages Ed and Eq respectively to produce voltage commands. The full-bridge PWM inverters can be controlled by the unipolar SPWM technique or eight quadrant space vector PWM technique [11].