A Model Predictive Direct Torque Control Method for Eliminating the Effect of Common-Mode Voltage in Open-Winding Motors

Abstract

The invention discloses a model-predicted direct torque control method for eliminating the influence of the common-mode voltage of an open-winding motor. Further derive the leakage current i L Loop voltage, zero sequence current i 0 The relationship between the loop voltage and the two common-mode voltages; according to the leakage current i L loop and zero sequence i 0 According to the characteristics of the loop, the requirement that the common-mode voltage does not affect the two loops is obtained, and the voltage vectors that meet the requirements are selected to form a complete control system voltage vector set; the voltage vector set is combined with the motor predictive control model and the cost function to obtain The optimal voltage vector when the cost function is minimized is applied to the inverter to control the motor; the invention can simultaneously eliminate the influence of the common-mode voltage on the zero-sequence current that affects the efficiency and the leakage current that affects the life, and can Increase the operating efficiency of the motor and extend the life of the motor.

Description

technical field [0001] The invention relates to the technical field of motor control, in particular to a model predictive direct torque control method capable of eliminating the influence of the common-mode voltage of an open-winding motor. Background technique [0002] In a three-phase motor drive system, when the motor is driven by an inverter using PWM technology, there is a common-mode voltage at the neutral point of the motor winding, and the common-mode voltage generates leakage current through the parasitic capacitive impedance, which will affect the shaft and The bearing causes damage and affects the life of the motor; if there is a zero-sequence path in the system, the common-mode voltage will generate a zero-sequence current, resulting in additional motor loss and heat, reducing the efficiency and stable operation of the system. [0003] In recent years, due to the advantages of high output power, multiple voltage vectors, and strong fault tolerance, open-winding m...

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Problems solved by technology

However, when the inverters connected to both ends of the open-winding motor share a power supply, due to the existence of the zero-sequence path, the common-mode voltage will cause zero-sequence current, so the influence of the common-mode voltage must be eliminated in the single-supply open-winding system. In order to effectively improve the efficiency of the system

[0004] Due to the different mechanisms and ways of common-mode voltage’s influence on leakage current and zero-sequence current, these two influences will exist simultaneously in single-supply open-winding motors. At present, there are few literatures that can use simple and easy-to-implement methods to simultaneously reduce The influence of these two aspects

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