Similarities and differences between Frequency Inverter and VFD (Variable Frequency Drives)

Frequency Inverter and VFD (Variable Frequency Drive) are the most widely used driving equipment in the transmission system. When talking about the difference between the two, most people blurt out that a Frequency Inverter is commonly used in low-end mechanical equipment, while a VFD (Variable Frequency Drive) is mostly used in high-end mechanical equipment. This is a relatively general term. Today we will distinguish the similarities and differences between the two in detail.

1. Definition and function
Frequency Inverter and Variable Frequency Drive are electronic devices used in modern electric drives. They can transform traditional non-variable frequency electrical equipment into variable frequency speed-adjustable electrical equipment that adapts to different load requirements and can reduce the energy consumption of the electric drive system. , improve transmission efficiency and control accuracy. Their function is to convert AC power into DC power and use PWM waveforms to control the frequency and speed of the motor to improve control accuracy, operational stability, and efficiency.

2. Control objects
Frequency Inverter is mainly used to control the rotation speed and output frequency of AC motors and is suitable for single-unit controlled low-power drive systems, such as household air conditioners, refrigerators, etc. VFD is used to control the rotation speed and output frequency of three-phase asynchronous motors and is suitable for the control of high-power drive systems, such as water pumps, fans, compressors, oil drilling rigs, etc.

3. Control method
The control method of the Frequency Inverter is relatively simple. Most of them only have a PCB board on the backplane. The motor power supply and the main controller are separated. The control signal is directly converted into a PWM waveform through the trigger and sent to the motor. The control capability is weak. VFD (Variable Frequency Drive) uses a variety of control methods, including open-loop control, vector control, and direct torque control. It also includes a variety of protection mechanisms and encoder feedback systems, which can control the operating status of the motor more precisely to ensure Operational effectiveness and safety.

4. Other differences
In addition to differences in control objects and control methods, VFD (Variable Frequency Drive) also has higher working stability, wider grid adaptability, and more flexible applications, and can cope with the electrical transmission needs of various industries. At the same time, due to differences in factors such as its internal circuits, software, and control systems, its cost is relatively high, and installation and debugging are relatively difficult.

To sum up, VFD (Variable Frequency Drive) and Frequency Inverter are both electronic speed control devices, but there are big differences in control objects, control methods, performance, etc., and the use occasions are also different. Therefore, comprehensive comparison and consideration need to be made based on different needs before selection.