VFD (Variable-frequency Drive) industry is widely used to promote the development of industrial energy conservation

With the continuous improvement of industrial automation, VFD (Variable-frequency Drive) has also been widely used. Energy conservation and environmental protection, as the core of Chinese industrial economic development, not only point out the direction for the sustainable development of Chinese industry, but also effectively Stimulate the sustainable development of Chinese VFD (Variable-frequency Drive) industry, enable Chinese VFD (Variable-frequency Drive) industry to continuously expand the market share of the industry, and become an important basis for Chinese industrial economic development with its strong development force.

Frequency conversion energy saving is mainly used in occasions where it is necessary to change the speed of the AC motor and change the characteristics of the driving machinery to meet the requirements of the production process, and it is mostly used in fans and water pumps. When the motor can only run at the rated speed, its driving machinery can only run at a certain rated speed.

When the production process requires adjustment of the process parameters, the flow rate can only be changed by increasing (decreasing) the system resistance, and the motor is always running under the rated condition, resulting in a waste of electric energy. Such as fans, pumps and other equipment, the traditional speed regulation method is to adjust the outlet (or inlet) baffle and valve opening to adjust the air supply and water supply. the probability of system failure. When using frequency conversion speed regulation, if the flow requirement is reduced, the requirement can be met by reducing the pump or fan speed.

On the whole, VFD (Variable-frequency Drive) mainly achieves energy saving effect through power factor compensation and soft start. In terms of power factor compensation, since reactive power will increase line loss and heat generation of equipment, coupled with the reduction of power factor, the active power of the grid will decrease. Among the large reactive power consumption lines, the equipment use efficiency is low and the waste is serious. After using the frequency conversion speed control device, the VFD (Variable-frequency Drive) internal filter capacitor acts, thereby reducing the reactive power loss and increasing the active power of the grid.

In terms of soft start and energy saving, the hard start of the motor will have a serious impact on the power grid, and at the same time, the requirements for the capacity of the power grid are too high. When a large current and vibration are generated during start-up, the damage to the baffle and valve will be great, and the use of equipment and pipelines will be greatly damaged. Life expectancy is extremely unfavorable. Using the soft start function of VFD (Variable-frequency Drive) will start the starting current from zero, reduce the impact on the power grid and the requirements on power supply capacity, prolong the service life of equipment and valves, and thus save equipment maintenance costs.

However, it should be noted that the problem of "small horses and large carts" should be avoided in the use of VFD (Variable-frequency Drive). The reason for this problem is based on the limitation of working conditions when the design was put into production at that time, so that in order to save money during design and installation, many places have adopted the setting that the frequency conversion power is less than the rated power of the motor. However, with the development of technology and changes in process and production conditions, the problem of "small horses and large carts" will inevitably appear, resulting in the failure of VFD (Variable-frequency Drive) to operate normally.

Therefore, during the trial period of the frequency conversion device, in order to prevent problems before they happen, detection and adjustment should be carried out in advance to avoid the above problems. In addition, after 6 to 10 years of normal use, VFD (Variable-frequency Drive) tends to enter a period of high incidence of failures. Failures such as component burnout, failure, and frequent activation of protection functions often occur, seriously affecting its normal operation.