Frequency conversion speed regulation technology emerged after the advent of thyristors, but it wasn't until the 1970s that frequency converters made their debut. This delay is attributed to the full development of frequency converter technology alongside advancements in power electronic devices, microelectronics, computer technology, and automatic control theory. Progressing from the initial power transistor (GTR) and gate-off thyristor (GTO) to today's intelligent power integrated circuit (PIC) and intelligent power module (IPM). Evolving from the original 8-bit CPU, 16-bit CPU to the modern 32-bit digital signal processor (DSP). Advancing from general V/f control, vector control to direct torque control, intelligent control. At each stage of IT technology development, inverter technology has also advanced. Now, owing to the speed regulation and energy-saving capabilities of frequency converters, coupled with continuous cost reduction, we find ourselves in the era of widespread promotion and application of frequency converters.

The broad utilization of frequency converters will inevitably demand an increasing number of people to acquire proficiency in frequency converter technology. In the near future, frequency converter technology will become as commonplace as ordinary electrical technology. Hence, mastering the application technology of frequency converters will be a prerequisite for every electrician and technician's knowledge base.

In the realm of frequency conversion speed regulation systems, general-purpose frequency converters are more commonly used. "Universal type" is contrasted with "dedicated type." The term "universal" implies compatibility with a general-purpose three-phase asynchronous motor, making it suitable for a variety of performance loads with numerous optional functions. General-purpose inverters are categorized into general-function V/f control general-purpose inverters, high-function V/f control general-purpose inverters, and vector control general-purpose inverters. Over time, general-function V/f control general-purpose inverters are being gradually replaced by advanced functional V/f control and vector control general-purpose inverters.

Both high-function V/f control and vector control can independently control and adjust speed and torque, with vector control offering superior dynamic performance. Its speed regulation capabilities can now rival DC speed regulation. As the speed regulation ratio is not very large (below 1:1000), there is a tendency for vector control to gradually replace DC speed regulation. Therefore, understanding the application of general-purpose inverters is crucial knowledge. The application of frequency converters encompasses the design of frequency conversion speed regulation systems, the selection of frequency converters and peripheral equipment, the installation and debugging of frequency conversion speed regulation systems, the function application and parameter setting of frequency converters, fault diagnosis and processing of frequency converters, and the selection, maintenance, and repair of frequency converters. Among these aspects, the function application and parameter setting of the inverter stand out as a particularly important part. It is knowledge that all engineering and technical personnel involved in inverter technology must master, especially those on the production site and technical staff. Acquiring knowledge of inverter function application and parameter setting is essential.