Commutation torque ripple suppression device and suppression method for brushless DC motor

Abstract

The present invention provides a commutation torque ripple suppression device and a suppression method for a brushless DC motor. The device comprises two power switches (S1 and S2), a power diode (VD) and a capacitor (C). The collector of the second power switch (S2) is connected in series with the cathode of the capacitor (C). The anode of the capacitor (C) is connected with the cathode of the power diode (VD). The emitter of the second power switch (S2) is connected with the negative electrode of a power supply. The collector of the first power switch (S1) and the anode of the power diode (VD) are connected with the positive electrode of the power supply. The emitter of the first power switch (S1) is connected with the cathode of the capacitor (C). According to the technical scheme of the invention, the advantages of fewer components, simple control method, low cost and easy implementation are realized. If the device breaks down, the normal operation of the motor is not influenced at all. Therefore, the fault tolerance rate is high. The device and a bus are connected in parallel, so that the transformation and the upgrading of existing equipment are facilitated.

Description

technical field [0001] The invention relates to a brushless DC motor control device, and the invention also relates to a brushless DC motor control method. Specifically, it is a device and method for suppressing commutation torque ripple of a brushless DC motor. Background technique [0002] Brushless DC motors have been widely used in various industrial fields due to their high power density, high torque, high power factor, simple control, and low maintenance cost. However, due to the torque ripple of the motor, its application in the high-precision field is limited. [0003] The main causes of torque ripple are as follows: [0004] 1. There are errors in the manufacturing process, which will lead to periodic torque ripple. [0005] 2. The PWM modulation method will cause small-amplitude high-frequency torque ripple. [0006] 3. Commutation torque pulsation, which accounts for about 50% of the total pulsation, is the most serious factor affecting the brushless DC motor....

AI Technical Summary

Problems solved by technology

[0004] 1. There are errors in the manufacturing process, which will lead to periodic torque ripple

[0005] 2. The PWM modulation method will cause small-amplitude high-frequency torque ripple

[0006] 3. Commutation torque pulsation, which accounts for about 50% of the total pulsation, is the most serious factor affecting the brushless DC motor

If the drop rate of the off-phase current is not equal to the rise rate of the on-phase current, it will cause fluctuations in the non-commutation current, resulting in commutation torque ripple

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