[Objective] Current sampling serves as a critical component to achieve efficient and stable operation of the motor

and its accuracy directly determines the motor control performance. In brushless direct current motor (BLDCM) control systems

conventional multi-sensor schemes not only increase the hardware costs

but also degrade the closed-loop control accuracy due to sensor parameter drift or characteristic differences. Aiming at the problem of current reconstruction blind zones of single current sensor in the low index modulation regions and sector boundary areas under space vector pulse width modulation (SVPWM)

this paper proposes a midpoint sampling phase-shifting method in the second half cycle of pulse width modulation (PWM). [Methods] By adjusting the phase of the PWM pulse

the phase compensation set two times the minimum sampling time after the falling edge as the actual sampling window and implemented the current sampling operation at the midpoint of the window. This method not only ensured that the minimum sampling time requirement was met

but also reserved a sufficient margin for the signal aberration caused by the switching noise

which effectively reduced the uncertainty of sampling timing and current transient fluctuations. [Results] Simulation and experimental results demonstrated that the proposed method effectively reduced the current reconstruction blind zones in low index modulation regions and sector boundary areas. Compared with the uncompensated phase-shifting method

the accuracy of reconstructed phase current was significantly improved under the proposed compensation method

and the reconstruction error was stabilized at a lower level. The maximum error was reduced from 6.8 A to 1.38 A

which was a reduction of 79.71%

and the total harmonic distortion was reduced from 26.38% to 3.37%

which was a significant effect of harmonic suppression. [Conclusion] The method proposed in this paper effectively addresses the challenge of single-sensor current reconstruction in SVPWM-driven BLDCM systems

while reducing the hardware costs

and provides a feasible reference for the current sampling design of motors.