The application of high-power power electronics technology in power systems has become increasingly widespread. High voltage and high-power variable frequency speed regulation technology is one of the most effective means to solve the energy waste problem caused by traditional driving methods. Electronic power transformers, as a new type of power transformer, have the potential to meet many new requirements of future power systems. When the converter serves as the power supply for the motor, the common mode voltage it generates has a lot of negative effects on the motor, leading to a reduction in motor life and an increase in corresponding industrial costs. Studying the characteristics of common mode voltage and the measures to suppress common mode voltage are of great practical significance. This article first introduces the basic composition and working principle of high-voltage frequency converters, points out the advantages of universal AC-DC-AC frequency converters, and introduces several widely used topology structures. Analyzed the mechanism of common mode voltage generation in a universal AC-DC-AC inverter two-level inverter and three-level inverter. By analyzing the common mode voltage circuit, the relationship between the common mode voltage of the converter and the common mode voltage of the motor was obtained, thus transforming the study of the common mode voltage of the motor into the study of the common mode voltage of the converter. In terms of measures to suppress common mode voltage, this article mainly introduces them from two perspectives: hardware and software. The introduction of hardware measures is also from two aspects: active and passive. The article lists several typical hardware measure structures and briefly explains their working principles. The software measures focus on the reduction or elimination strategy of the common mode voltage of the converter itself. For three-level converters, the suppression measures of common mode voltage are introduced from two aspects: sine pulse width modulation (SPWM) strategy and space vector modulation (SVM) strategy.