There are many types of frequency converters, which can be classified according to requirements, such as applications, conversion methods, power supply characteristics, voltage regulation methods and frequency shifts.
They are divided according to use.
Frequency changer can be divided into two types according to their applications: general frequency converters and special frequency converters.
Universal inverters are more versatile inverters. This type of inverter simplifies system operation and is mainly designed for energy storage and is used in applications that do not require high system efficiency, such as water pumps, fans and blowers.
Special Variable frequency power supply are frequency converters specially designed and designed for specific parts or areas, with special features and advantages that can be used to efficiently change the frequency and adjust the speed.
At present, these systems are mainly used in fan drive systems, constant pressure water systems (water pumps), these work with machine tools, frequency controllers, etc. special frequency converters for injection molding. These systems are used to control appliances, fabrics, elevators, etc.
The classification is based on the transformation method.
Variable frequency AC power source are broadly classified into AC-DC-AC converters and AC-AC converters according to the conversion method.
Classification by reinforcement type .
Frequency converters can be classified into voltage-type Adjustable Frequency Power Supplies and current-type frequency converters according to the type of power source.
A feature of voltage-source inverters is that the intermediate circuit uses a capacitor as an energy storage device to limit the reactive power of the load. The DC voltage is constant and is mostly used in situations where the load changes abruptly.
A feature of current-type inverters is that they use an inductor as an energy storage device in the intermediate circuit to limit the reactive power of the load, that is, to suppress changes in current. They are mainly used in situations where the load current fluctuates. Suitable for feedback braking and sewing machines that frequently rotate in both forward and reverse directions. Voltage-type inverters and current-type inverters not only have different circuit configurations, but also differ in functionality and application range.
In addition to the above classification methods, frequency sensors can be classified into voltage/frequency (U/f) sensors, which use sliding frequency, vector-driven devices, direct torque-driven devices, depending on the frequency used. They can be divided into converters, etc. .
Frequency controllers can be divided into PAM controllers and PWM controllers according to voltage regulation techniques. PAM (Pulse Amplitude Modulation, Pulse Amplitude Modulation) can change the pulse frequency of the pulse train according to certain rules. The pulse amplitude is controlled by the microprocessor. PWM (Pulse Width Modulation, Pulse Width Modulation) can change the frequency of the pulse train according to certain rules. The pulse width is controlled by the microprocessor. Frequency sensors are divided into three input and three output frequency bands according to the number of phases of the input current, and the change each frequency and the three outputs. The input and output sides of the inverter in/three three-phase alternating current are used. The input side of the three-input inverter is powered by single-phase AC power, while the output side is powered by three-phase AC power.
