Performance comparison of two FPE sensorless control methods on a direct torque controlled interior permanent magnet synchronous motor drive

This paper proposes a simplified Fundamental PWM Excitation (FPE) sensorless control method on IPMSMS direct torque control drives. This method is based on a five-segment PWM and the measurement of two active voltage vectors and one zero voltage vector during the first half of each PWM modulation cycle in order to obtain di/dts and estimate the rotor position therefrom. Compared to the conventional FPE, this method requires one fewer zero vectors for PWM pulse extension at high speed and high load. This reduces the current and flux ripples. The simulation results are shown to verify the effectiveness of the proposed FPE sensorless control and the performance comparison between proposed FPE and conventional FPE. Experiment results shows the accuracy of current derivative estimation under this simplified FPE method and compare the estimated rotor position with a shaft encoder.