Inverter classification by purpose
Inverters are used in many industries and can be divided into the following categories according to their uses.
(1) General purpose inverter
The so-called general-purpose frequency converter refers to the frequency converter that is used in conjunction with ordinary cage asynchronous motors, can adapt to various loads of different nature, and has a variety of optional functions.
Its main feature is the use of a voltage source AC-DC-AC main loop structure, in which a diode rectifier is used to rectify the constant intermediate DC voltage from the AC power source, and the AC output from the intermediate voltage to the variable voltage and frequency conversion adopts fully controlled switching devices or It can only power the pulse width modulation inverter composed of wood blocks.
It has occupied most of the market of 0.5~500KV*A medium and small-capacity variable frequency speed regulation devices in the world. At present, the development trend of general-purpose inverters is integration of main control, miniaturization, low electromagnetic noise, specialization, and systemization.
(2) High-performance dedicated inverter
Dedicated inverters emerged with the large-scale promotion of inverters in the original equipment manufacturer (0EM) industry. It includes existing controllers (PLC, single-chip or other controllers) and integrated solutions for adding inverters. In the general frequency converter technology, the industry-specific design of software and hardware was carried out, and finally the industry-specific frequency converter was formed.
At present, the industry-specific frequency converters that are widely used include: special frequency converters for textiles, water supply, injection molding machines and elevators.
(3) High frequency inverter
The output frequency of general frequency converter is generally 120~400Hz. Some applications require high speed occasions, need to use high frequency inverter. The output frequency of high frequency inverter is 1500~3000Hz, and other functions are the same as general inverter.
With the development of inverter technology, the output frequency of high-frequency power supplies is also continuously increasing, so higher speed drives will become possible. In addition, compared with a high-speed drive system that uses a mechanical speed-increasing device, its reliability is better, and maintenance and repair are simpler.
(4) Single-phase inverter
The input side of the inverter is a single-phase power supply, and the output side is a three-phase alternating current. This type of inverter usually has a small capacity and is suitable for single-phase power supply. Most of the frequency converters in household appliances fall into this category.