Rotor Position Extraction by Carrier Frequency Component Method (Cfcm) in Space Vector Modulation (Svm) for Ipm Drives

No Thumbnail Available



Journal Title

Journal ISSN

Volume Title


Addis Ababa University


Sensorless drive of interior permanent magnet (IPM) synchronous motors is possible because the motors’ rotor position information is attached to stator inductance (due to magnetic saliency) and back electromotive force (EMF). The vector controlled sensorless drive, which uses the inductance variation of this motor, comprises a cascaded feedback and single loop SISO control systems. A cascade PI controller is introduced. The inner feedback loop performs the control of q-axis voltage according to the required q-axis current obtained from speed controlling outer loop. The position of the motor is obtained by using high frequency injected signal component of the stator’s currents. High frequency signals increase the bandwidth and reliability of the band pass filter. But further increase in injection frequency results higher THD. In order to find the exact position of the rotor from this saliency, two stationary reference frames are used. PI controller is also introduced for the single loop d-axis feedback system. This loop operates the regulation of the d-axis current for MTPA operation. An SVPWM is used to generate an efficient VSI switching sequence from the reference voltages obtained from the vector controller. The performance of this PWM technique is compared with the sinusoidal PWM in terms of total harmonic distortion (THD) and DC bus voltage conversion ratio. The d-q frame mathematical model of IPMSM, transformed using Park’s and Clarke’s transformation, is investigated on SIMULINK® SimPowerSystems™. The models are based on a per-unit (pu) analysis. Simulation results show that, SVPWM has a 22% low THD value than SPWM, and it improves the DC bus voltage conversion by 7%. The rotor’s position is successfully extracted from the high frequency component of rotor current for different motor operations, and the speed response of the control of the drive system is smooth. Key Words: Interior Permanent Magnet (IPM) Motor, Vector Controlled Motor Drives, Space Vector Pulse width Modulated (SVPWM) voltage source inverter, SIMULINK®



Interior Permanent Magnet (IPM) Motor; Vector Controlled Motor Drives;Space Vector Pulse width Modulated (SVPWM) voltage source inverter; SIMULINK® SimPowerSystems™/ MATLAB