Siemens frequency converters, with their strong brand effect, have broken the monopoly position of Japanese brand frequency converters in the Chinese market. According to statistics from professional market research institutions, Siemens' high and low voltage frequency converters have already ranked first in the Chinese market.   The earliest use of Siemens frequency converters in the Chinese market was in the steel industry. However, at that time, motor speed regulation was mainly based on DC speed regulation, and the application of frequency converters was still an emerging market. However, with the continuous development of electronic components and the continuous maturity of control theory, frequency conversion speed regulation has gradually replaced DC speed regulation and become the mainstream of driving products, Siemens frequency converters have achieved large-scale development in this huge Chinese market due to their strong brand effect. Siemens' successful development in the Chinese frequency converter market can be said to be a perfect combination of Siemens brand and technology. The early Siemens inverters we can encounter in the Chinese market were mainly SIMOVERT A for current sources and SIMOVERT P for voltage sources. These inverters also entered the Chinese market together mainly due to the introduction of equipment, and there are still a small number of them in use. Later, the main products sold in the Chinese market were MICRO MASTER and MIDI MASTER, as well as the most successful series of Siemens inverters, SIMOVERT MASTERDRIVE, That is what we often refer to as the 6SE70 series. It not only provides AC frequency converters for general use, but also provides DC bus solutions with multiple motor drives required for special industries such as papermaking and chemical fiber. Of course, Siemens has also launched an ECO frequency converter that, in my personal opinion, has been technically unsuccessful but has been quite successful in the market. The technical failure is mainly due to its high failure rate, and the market success is mainly due to its surpassing Fuji frequency converter to become the first brand in the Chinese market. Currently, Siemens' main models in the Chinese market are the MM420 and MM440.6SE70 series.