The background of the birth of frequency conversion technology is the extensive demand for stepless speed regulation of AC motors. The traditional DC speed regulation technology is limited by its large size and high failure rate.
After the 60s of the 20th century, thyristors and their upgraded products were widely used in power electronic devices. However, its speed regulation performance is far from meeting the needs. In 1968, high-tech enterprises represented by Danfoss began mass production of frequency converters, opening a new era of frequency converter industrialization.
Since the 70s of the 20th century, the research on pulse width modulation variable voltage conversion (PWM-VVVF) speed regulation has made a breakthrough, and the improvement of microprocessor technology after the 80s of the 20th century has made it easy to implement various optimization algorithms.
In the middle and late 80s of the 20th century, VVVF inverter technology in developed countries such as the United States, Japan, Germany, and Britain was put into practice, and the commodity was put into the market and widely used. The earliest inverters may have been developed by the Japanese who bought a British patent. However, the United States and Germany rely on the advantages of electronic component production and electronic technology, and high-end products quickly seize the market.
Compared with the development of foreign inverters, the application of inverters in China started late, and it was not widely promoted until the late 90s of the 20th century. The development status of domestic frequency conversion technology can be summarized as: the overall technology of frequency converter is relatively backward, and there is a big gap compared with the advanced achievements made by foreign countries in frequency conversion speed regulation research; At present, the key power devices required in the production of inverters can hardly be produced by domestic manufacturers, resulting in our core technology being subject to foreign countries and must rely on imports; The main products are concentrated in low-voltage products and low-end markets. Due to the low level of product reliability and process, the current domestic inverter products are mainly oriented to the low voltage and performance requirements of the market, and the high performance and high power market is mainly occupied by large foreign companies.
After entering the 21st century, domestic inverters have gradually risen and have gradually seized the high-end market. Shanghai and Shenzhen have become the forefront of the development of domestic inverters.