A common mode noise suppression method based on three-phase AC motor drive system

Abstract

The present invention discloses a three-phase AC motor driving system for suppressing common-mode noise and a method, wherein the driving system comprises a DC power supply, a DC bus capacitor, a three-phase inverter, an additional bridge arm and an additional inductor. Based on a control system, the present invention provides a common mode noise suppression method, which realizes the suppressionof common-mode current and common-mode electromagnetic interference noise generated when the inverter drives the motor by real-time phase shifting of the pulse width modulation signal under the traditional SPWM modulation algorithm and adding the switching action of the additional bridge arm at the same time, thereby solving the problem of the common-mode noise when the inverter drives the three-phase AC motor. The system can select a small-capacity and low-cost switch tube to form an additional bridge arm, and achieve the effect of reducing the common-mode current and suppressing the common-mode noise, realizing the protection of the motor winding and the bearing insulation, and improving the system reliability.

Description

technical field [0001] The invention belongs to the field of AC motor and drive control, and more specifically relates to a common-mode noise suppression method based on a three-phase AC motor drive system. Background technique [0002] With the development of modern motor and power electronic control technology, AC motor frequency conversion speed regulation system driven by power electronic inverter has been widely used in the fields of industrial servo and traffic traction. Because the frequency conversion speed regulation function of the system is generally realized by the pulse width modulation technology combined with the high-speed switching characteristics of the inverter, there is a common-mode voltage characterized by high-frequency pulse sequences at the end of the motor winding. The common-mode current generated by the common-mode voltage is conducted along the motor winding, and is conducted to the ground terminal through the stray capacitance between the motor ...

AI Technical Summary

Problems solved by technology

[0003] Aiming at the above defects or improvement needs of the prior art, the present invention provides a common-mode noise suppression method based on a three-phase AC motor drive system, thereby solving the common-mode noise problem existing in inverter-driven three-phase AC motors

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