Abstract: This paper mainly introduces the asynchronous motor control strategy based on a cascaded multilevel high-voltage frequency converter. First, it introduces the circuit topology and basic principles of the multilevel frequency converter, as well as its carrier phase-shift SPWM control. Then, it introduces the widely used variable voltage frequency conversion control of asynchronous motors and presents simulation waveforms and experimental results. Finally, it focuses on the principle of vector control and the principle of sensorless vector control based on a model reference adaptive system, and verifies the results through simulation. Keywords: Multilevel; Carrier phase shift; Model reference adaptive system; Sensorless vector control 0 Introduction Energy-saving engineering for motor systems is one of the ten key national energy-saving projects launched by the National Development and Reform Commission during the "Eleventh Five-Year Plan" period. Frequency converters are the core components in energy saving of motor systems, and can efficiently utilize energy by adjusting the speed of the motor. High-voltage frequency converters, in particular, are used for high-voltage, high-power motors, and their energy-saving effect is even more significant, showing great market potential in China. Research on high-voltage, high-power frequency converters has attracted increasing attention. High-voltage, high-power frequency converters are mainly voltage source type, and their circuit structures are mainly of four types: (1) high-low-high two-level, mainly composed of input step-down transformer, low-voltage frequency converter, and output step-up transformer; (2) IGB directly connected in series two-level; (3) diode midpoint clamped three-level; (4) power unit series multi-level. Among them, the power unit series multi-level frequency converter has many advantages such as high power factor, low input and output harmonics, easy modularization, suitability for domestic power grid, and high reliability, so it is currently the most widely used. High-voltage asynchronous motors are mostly controlled by multi-level high-voltage frequency converters. Currently, the main control methods include variable-voltage variable-frequency (VVVF) control and rotor field-oriented vector control (VCo). VVVF is the most widely used method due to its simplicity and mature technology. VC and sensorless vector control (SVC) based on VVVF have attracted much attention due to their better steady-state and dynamic performance compared to VVVF. This paper studies the control strategies of high-voltage asynchronous motors, analyzes the principles and characteristics of VVVF, VC, and SVC, and presents simulation results. For details, please click: Asynchronous Motor Control Strategy Based on Cascaded Multi-Level High-Voltage Frequency Converter