Abstract : This paper introduces the basic structure of general-purpose frequency converters; fault types and causes; fault diagnosis and handling methods, and provides two fault examples. Keywords : Frequency converter, fault diagnosis and handling. General-purpose frequency converters have advantages such as wide speed range, high speed accuracy, fast dynamic response, high operating efficiency, high power factor, convenient operation, and easy interface with other equipment, and their application is becoming increasingly widespread. Paying attention to the fault diagnosis and handling techniques of frequency converters is of great significance to ensuring their normal operation. I. Introduction to General-Purpose Frequency Converters Currently, small and medium capacity general-purpose frequency converters have achieved generalization. Sinusoidal pulse width modulation (SPWM) or voltage vector control frequency converters using high-power self-turn-off switching devices as main switching devices have become the mainstream of general-purpose frequency converters. Frequency converters are divided into two main categories: AC-AC frequency converters and AC-DC-AC frequency converters. Due to the smaller number of power switching components used in the main circuit of voltage-type AC and DC-AC frequency converters, the electrical side generally uses diode rectification, resulting in a high power factor, simple circuitry, and diversified control, they are the most widely used. Their basic structure is shown in Figure 1. The rectifier circuit module converts three-phase AC power into DC power; the inverter circuit module regularly controls the on/off switching of the main switching devices in the inverter to obtain three-phase AC power of any frequency; the intermediate DC link block is used to buffer reactive power; the control circuit module consists of arithmetic circuits, detection circuits, control signal input and output circuits, and drive circuits, mainly responsible for the switching control of the inverter, the voltage control of the rectifier, and various protection functions, and is also the part that frequently experiences failures. [b][align=center]For more details, please click: Inverter Fault Diagnosis and Handling[/align][/b]