An Adjustable Wide-Range Speed-Control Method for Sensorless IPMSM Drive Systems

Abstract

This paper proposes an adjustable wide-range speed-control method for sensorless IPMSM drive systems from standstill, low-speeds, middle-speeds, and high-speeds in the flux-weakening region. A sensorless method and an online parameter estimation method based on the measurement of current-slope under SVPWM with an extension compensation are proposed. The estimated rotor position, rotor speed, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d-q</i> axis inductances, magnetic flux, and torque of the IPMSM are precisely computed by using a current-slope measurement, and then a closed-loop speed control sensorless IPMSM drive system is implemented without requiring any external high-frequency signal injection or a complicated observer. In addition, to achieve a high-performance sensorless IPMSM drive system, the estimated parameters are used for real-time maximum torque per ampere control and flux-weakening control. Finally, the proposed sensorless IPMSM drive system provides a wide operation range from 1 r/min to 3000 r/min with excellent performance in constant-torque regions and flux-weakening regions. A digital signal processor, made by Texas Instrument, type TMS 320F2802, is employed to realize the control algorithm and estimation algorithm. Experimental results show the proposed sensorless IPMSM drive system achieves satisfactory responses, including <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\pm \,{\mathrm {2.5}}^{\circ }$ </tex-math></inline-formula> of electrical position estimation errors, good dynamic responses, and good tracking responses.