The basic purpose and function of the inverter

2021-08-01 08:36:14 jact_elec

The basic purpose and function of the inverter

The inverter is an electrical device that converts the power frequency AC power supply into an AC power supply with adjustable frequency and voltage, and realizes the speed adjustment of the AC motor.

It has been widely used in various fields of industrial and agricultural production.

JACT inverter has a wider range of applications and can be widely used in small and medium-sized power applications.

such as food machinery, plastic machinery, ceramic equipment, petroleum machinery, cable machinery, air compressors, machine tools, woodworking machinery, textile machinery, printing and packaging equipment , Chemical equipment, environmental protection equipment, transportation equipment, etc.

Basic functions of the inverter:

In addition to realizing the basic functions of motor frequency conversion and speed regulation, the frequency converter also has functions such as frequency control, automatic acceleration and deceleration, multi-speed operation, multiple parking methods, multiple control methods, braking, protection and communication.

  • frequency control function

The running frequency of the inverter can be controlled by the function keys on the operation panel, or the function parameter code preset, or the external analog quantity terminal, or by the upper computer through communication data.

  • automatic acceleration and deceleration function

The frequency converter can realize the optimal acceleration and deceleration control, and automatically set the shortest time of acceleration and deceleration according to the load status of the motor, or control the acceleration and deceleration current within the allowable value within the set shortest acceleration and deceleration time.

  • multi-speed operation

The inverter can execute multi-speed operation according to the preset speed value and running time, and divide a complete working process into several program steps. The rotation direction, running speed, working time or distance of each program step can be preset. The switching between each program step can be carried out automatically.

  • Multiple parking methods

The parking mode of the frequency converter can be selected from deceleration stop, free stop, deceleration stop + DC braking, which reduces the impact on mechanical parts and motors, thereby making the speed control system more reliable.

  • control function

The frequency converter has functions of torque boost, slip compensation, torque limit, catch and restart, as well as vector control, PID control and other functions.

  • braking function

The frequency converter has two modes: energy consumption braking and DC braking. Energy consumption braking is a kind of magnetic flux braking method. The deceleration and stopping of the motor is realized by reducing the output frequency of the inverter. When the inverter reduces the frequency, the synchronous speed of the motor will decrease accordingly. However, due to mechanical inertia , The rotor speed of the motor cannot drop immediately. When the synchronous speed n0 is less than the rotor speed of the motor, the phase of the motor current changes 180 degrees, and the torque on the motor shaft becomes the braking torque, so as to achieve braking, and the energy on the motor is consumed through the braking resistor.

DC braking is when the speed of the motor is reduced to the preset braking speed, the frequency converter injects a DC voltage into the motor to stop the motor and lock the rotor at zero speed.

  • protection function

The frequency converter has fault protection of the frequency converter itself and the fault protection of the motor. The fault protection functions of the inverter include overload protection, over current protection, regeneration over voltage protection, abnormal cooling fan, etc. The fault protection functions of the motor include grounding protection, overload protection, over current protection, over voltage protection, under voltage protection, phase loss protection, over frequency protection, stall protection, etc.

  • communication function

The inverter has an RS232/485 communication interface, which can realize the communication function of the host computer to the inverter, accept the operating instructions of the host computer or upload the running status of the inverter. Perfect software functions and standardized communication protocols can realize flexible system configuration and form a field bus system.