The purpose and difference between general inverter and special inverter

The purpose and difference between general inverter and special inverter

Tue Jun 28 13:54:49 CST 2022

For users, the most concern is the purpose of the inverter. According to different purposes, the frequency converter can be divided into general frequency converter and special frequency converter.
1. General purpose inverter
Universal frequency converter is the most widely used and the largest in the frequency converter family. As the name implies, the general purpose inverter is characterized by its versatility. With the development of frequency conversion technology and the continuous expansion of market demand, general-purpose inverters are developing in two directions: one is a low-cost simple general-purpose inverter that simplifies some system functions for the main purpose of energy saving. It is mainly used in Water pumps, fans, blowers and other occasions that do not require high system speed regulation performance, and have the advantages of small size and low price; second, the design process fully considers the high performance, multi-function and general purpose of the application When the inverter is in use, the user can select an algorithm to set various parameters of the inverter according to the characteristics of the load, or select various spare options provided by the manufacturer to meet the special needs of the system according to the needs of the system. In addition to all applications of simple inverters, high-performance multifunctional general-purpose inverters can also be widely used in elevators, CNC machine tools, electric vehicles and other occasions that have high requirements for the performance of the speed control system. In the past, general-purpose inverters basically adopted the U/f control mode with a relatively simple circuit structure. Compared with the VC mode, the torque control performance was worse. However, with the development of frequency conversion technology, some manufacturers have introduced general-purpose frequency converters using VC to meet the needs of the increasingly competitive frequency converter market. This kind of multifunctional general frequency converter can be switched to U/f control operation or VC operation mode according to user needs, but the price is the same as that of U/f mode general frequency converter. Therefore, with the development of power electronic technology and computer technology, the cost performance of frequency converters will continue to increase in the future.

2. Dedicated frequency converter
(1) High-performance dedicated inverter.
With the development of control theory, AC speed regulation theory and power electronics, the VC of asynchronous motors has been developed. The AC servo system composed of VC frequency converter and its special motor has reached and exceeded the DC servo system. In addition, because asynchronous motors also have many advantages that DC servos do not have, such as strong environmental adaptability and simple maintenance, such high-performance AC servo inverters are gradually replacing DC servo systems in high-speed and high-precision control.
(2) High frequency inverter.
High-speed motors are often used in ultra-precision machining. In order to meet the needs of its driving requirements, a high-frequency inverter controlled by PAM has appeared. Its output main frequency is up to 3 kHz, and the maximum speed when driving a two-pole asynchronous motor is 18000 r/min.
(3) High-voltage inverter.
High-voltage inverters are generally large-capacity inverters with a maximum power of 5000 kW and voltage levels of 3 kV, 6 kV and 10 kV.