An Improved Finite Control Set Model Predictive Current Control with CMV Reduction for Three-Phase VSIs

Abstract

In the motor control systems fed by voltage source inverters (VSIs), common-mode voltage (CMV) will damage the insulation and bearing of the motors and then shorten the service life of the motors. With the popularization of the model predictive current control (MPCC), CMV reduction methods based on MPCC have become a research hotspot. Among them, the CMV reduction method based on synthesized zero virtual voltage vector (zero V <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> ) is simpler and more convenient. However, the existing method of synthesizing zero V <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> s with two opposite voltage vectors has the problem of increasing the change rate of output voltage (dv/dt). The high dv/dt of VSIs will result in overvoltage at the motor terminals and further aggravating the motor insulation damage. For this purpose, an improved CMV reduction method based on FCS-MPCC is proposed to reduce the dv/dt in this paper. Instead of synthesizing zero V <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> s with two opposite voltage vectors, all of the six active voltage vectors were used to synthesize zero V <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> s to realize dv/dt reduction. Meanwhile, the proposed method can maintain good current control performance. Simulations are carried out to verify the effectiveness of the proposed method.