Three-phase AC motor driving system suppressing common-mode noise

Abstract

The present invention discloses a three-phase AC motor driving system suppressing common-mode noise, wherein the system comprises two sets of three-phase inverters, an additional load circuit, a driving control circuit, a sampling feedback circuit and two additional parallel bridge arms and correspondingly coupling inductors. Based on the control system, the present invention provides a common mode noise suppression method, which can reduce the common mode current and EMI noise generated by a general inverter driving motor when the maximum DC bus voltage utilization rate is achieved so as to suppress the problems of continuing damaging the components of motor insulators and bearings, thus resolving the technical problem of common-mode noise of an inverter-driven three-phase AC motor. The system of the invention can select an additional bridge arm with a small capacity and low cost switch tube, and can achieve the beneficial effects of reducing the common mode current, suppressing the common mode noise, protecting the motor winding and the bearing insulation, and improving the system reliability.

Description

technical field [0001] The invention belongs to the field of AC motors and drive control, and more specifically relates to a three-phase AC motor drive system capable of suppressing common-mode noise. 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 field of servo and traffic traction. Because the system's frequency conversion and speed regulation function is realized by 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 winding end of the motor. 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 winding and the casing or the bea...

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Problems solved by technology

[0003] Aiming at the above defects or improvement needs of the prior art, the present invention provides a three-phase AC motor drive system that suppresses common-mode noise. The common-mode current and electromagnetic interference noise generated when the inverter drives the motor suppresses the problem of continuous damage to the motor insulation and bearings, thereby solving the technical problem of the common-mode noise of the three-phase AC motor driven by the inverter

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