Improving dynamics of vector controlled IM drive by resampling SVM under low frequency ratio

Field Oriented Control (FOC) technique is one of the most frequently applied algorithm to control the torque and the speed of a three-phase electric drive. The paper focuses on high speed or high-pole count motor FOC drives when both the sampling over reference frequency ratio F and the carrier over reference frequency m_f is low. The paper presents that the stability range of a speed sensor-less FOC motor drive can be extended by recalculating the reference signal of the Space Vector Modulation algorithm at the negative peak of the carrier signal as well by approximating the rotor flux angle change over one half carrier period. The result was verified by computer simulations and laboratory measurements.