asokatechnologies@gmail.com 09347143789/09949240245

Search This Blog

Friday 5 March 2021

Analysis of the Three-Phase Inverter Power Efficiency of a BLDC Motor Drive Using Conventional Six-Step and Inverted Pulsewidth Modulation Driving Schemes

ABSTRACT:

 In this paper, the three-phase inverter power efficiency of a brushless DC (BLDC) motor drive

is analyzed theoretically and verified experimentally. An inverted pulsewidth modulation driving scheme has higher power efficiency than a conventional six-step driving scheme, particularly under low rotor speed due to less diode conduction power loss of Sync metal–oxide–semiconductor field-effect transistors (MOSFETs). However, the difference in the power efficiency decreases as the rotor speed increases; for a rotor speed above 1000 r/min, the difference in the power efficiency is negligible. In addition, the power efficiency of the inverted driving scheme drops further than one for the conventional six-step driving scheme with sampling frequency increase. It is due to the additional switching power loss of Sync MOSFET. The theoretical analysis of power loss in a three-phase inverter verifies the experimental results.

KEYWORDS:

1.      Brushless dc (BLDC)

2.      Inverted pulsewidth modulation (PWM)

3.      Power efficiency

4.       Power loss

5.      Three-phase inverter

SOFTWARE: MATLAB/SIMULINK

 CONCLUSION:

In this paper, two different driving schemes for a BLDC motor drive, conventional six-step and inverted PWM, are analyzed in terms of power efficiency and loss to facilitate the understanding of the type and amount of the power loss in a three-phase inverter driving BLDC motor. Besides the conduction and switching power loss of HS and LS MOSFETs, the additional conduction and switching power loss from Sync MOSFET driven by an inverted PWM driving scheme must be compared to the conduction power loss from the diode of Sync MOSFET to select the more power-efficient driving scheme of the two schemes studied. The power efficiency of the three-phase inverter driven by the inverted PWM driving scheme is greater than that driven by the conventional six-step  driving scheme, particularly in the low rotor speed range. This is due to the reduction of the Sync MOSFET diode conduction power loss in the three-phase inverter driven by the inverted PWM driving scheme.

REFERENCES:

[1] J. Shao, D. Nolan, and T. Hopkins, “A novel direct back EMF detection for sensorless brushless DC (BLDC) motor drives,” in Proc. 17th Annu. IEEE Appl. Power Electron. Conf. Expo., Dallas, TX, USA, vol. 1, Mar. 2002, pp. 33–37.

[2] P. Yedamale, “Brushless DC (BLDC) motor fundamentals,” Microchip Technol. Inc., Chandler, AZ, USA, Appl. Note. 20:3-15, 2003.

[3] M. R. Rahman and P. Zhou, “Analysis of brushless permanent magnet synchronous motors,” IEEE Trans. Ind. Electron., vol. 43, no. 2, pp. 256–267, Apr. 1996.

[4] A. Hughes and W. Drury, Electric Motors and Drives: Fundamentals, Types and Applications. Oxford, U.K.: Newnes, 2013.

[5] J. S. Lawler, J. M. Bailey, J. W. McKeever, and J. Pinto, “Limitations of the conventional phase advance method for constant power operation of the brushless DC motor,” in Proc. IEEE Southeast Con, Apr. 2002, pp. 174–180.