In this paper a new position sensorless approach for brushless direct current (BLDC) motor drive using synchronous reference frame (SRF)-PLL method is utilized with zero DC offset. The rotor angular position is estimated with SRF-PLL from the terminal voltages of the motor. It is found that for a BLDC motor, the phase of the terminal voltage defines the rotor position. Therefore, the conventional back EMF ZCP-based method can be replaced by SRF-PLL for position estimation, which offers good accuracy, enhanced filtering, and robustness under the DC link voltage variation. The estimated position is converted to virtual commutation signals. The presence of a DC offset in the input of PLL causes oscillation in fundamental frequency, which adds error in position estimation. This error degrades motor performance with additional current and torque ripples. Therefore, a DC offset rejection technique is added with a conventional SRF-PLL for further improvement in motor drive performance for EV applications.
Improved SRF-PLL Based Position Sensorless BLDC Motor in EV Drive With DC Offset Rejection
2023-11-28
1321628 byte
Conference paper
Electronic Resource
English
Bi-directional Position and Speed Estimation Algorithm for Sensorless Control of BLDC Motor
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