Which country invented the inverter?
There are two kinds of PFC, one is passive PFC (also called passive PFC), and the other is active PFC (also called active PFC). Passive PFC generally uses the inductance compensation method for the phase between the fundamental voltage and current of the AC input is decreased to improve the power factor, but the passive power factor PFC is not very high, can reach 0.7~0.8; PFC by active inductor and capacitor and electronic components, small size, power factor could be very high, but the cost is higher a passive PFC.
Since 1960s, thyristor and its upgrade products have been widely used in power electronic devices. But its speed performance is far from meeting the needs. In 1968, the high-tech enterprises represented by Danfoss began to batch produce frequency converters and opened a new era of inverter industrialization.The beginning of 1970s, PWM VVVF (PWMVVVF) speed research get breakthrough, in 1980s after the microprocessor technology is perfect makes the algorithm easier to achieve.In the middle and late 1980s, VVVF converter technology in developed countries, such as America, Japan, Germany and Britain, was practical and the products were put into market and widely used. The earliest converters could have been bought by British and developed by British patent. However, the United States and Germany, with the advantages of electronic components production and electronic technology, high-end products quickly seize the market.Entered in twenty-first Century, the domestic inverter gradually rise, has gradually seize the high-end market. Shanghai and Shenzhen to become the forefront of domestic inverter development, emerged as Huichuan inverter, inverter, AMB inverter, frequency converters and a number of well-known domestic inverter. The AMB inverter was established in 1998, is one of China's first production of inverter manufacturers. Over the past decade, as the cornerstone to AMB rich cultural heritage, to support growth, enterprise quality system ISO9000 TUV earlier passed the certification, was awarded the "national high tech enterprise", has been appraised as "China user satisfaction of the ten domestic brands inverter".
The frequency converter is the electric energy control device that transforms the power frequency power to another frequency by the on-off function of the power semiconductor device.The frequency converter is mainly composed of rectifier (AC DC converter), filter, inverter (DC AC converter), brake unit, drive unit, detection unit, micro processing unit and so on.PFC is the term "power factor", which is mainly used to characterize the efficiency of electronic products in the utilization of electric energy. The higher the power factor, the higher the efficiency of power utilization.
PC power supply using bridge rectifier, capacitor filter circuit will make the traditional AC input current waveform distortion, inject a large amount of high harmonics to the power grid, so the grid side power factor is not high, only about 0.6, and caused serious harmonic pollution and interference on the power grid and other electrical equipment. As early as the early 80s, the harm caused by higher harmonic currents caused by such devices has attracted much attention. In 1982, the International Electrotechnical Commission formulated the IEC55 2 specification (revised standard harmonic limit later is IEC1000 - 3 - 2), the power electronic technology, many workers began to harmonic filtering and power factor correction (PFC) technology research. The introduction of PFC circuit in electronic power supply can greatly improve the utilization efficiency of electric energy.
The frequency converter is not developed by a certain individual, it is the research result of a large number of scientific research workers.The background of inverter technology is the wide demand of AC motor stepless speed regulation. The traditional DC speed regulation technology is limited because of its large size and high failure rate.
