Frequency converter selection

1. Brand selection
At present, there are hundreds of Frequency converter brands on the market, and the brand and model should be considered comprehensively according to various factors such as project budget, project requirements, and personal familiarity. In terms of market share, Japanese companies such as Toshiba, Mitsubishi, Fuji, and Panasonic are important variable frequency drive manufacturers in the world, and European and American brands: ABB, Siemens, Schneider, LG, Samsung, Hyundai Heavy Industries and other Korean rising stars are also in the market. Competing for the market, at the same time, Chinese companies such as Delta, Taian, Times, and Kangwo also have a certain degree of enthusiasm. However, the prices of these brands are definitely expensive. In the case of limited budget, we can consider some niche brands.

2. Type selection
The variable frequency drives used in the industry can be divided into two categories: general-purpose variable frequency drives and special-purpose variable frequency drives. The main technical indicators are: control mode, starting torque, torque and speed control accuracy, control signal type, speed control mode, communication interface, etc. Wait.

3. Choose the right capacity
It should be based on the rated current and load characteristics of the motor. The total load current does not exceed the rated current of the variable frequency drive. The capacity can be increased when working frequently or under heavy load.

4. Consider the type of load
According to the actual load, there are three types: constant power load, constant torque load, and reduced torque load. Fan and pump loads are characterized by reduced torque loads, and it is generally advisable to use frequency converters with U/f constant voltage frequency ratio control. Friction loads and potential energy loads such as hoists, cranes, injection molding machines, conveyors, conveyor belts, and mixers are basically constant torque loads. It is ideal to use high-function variable frequency drives with torque control functions; the spindle of metal cutting machine tools Coilers and uncoilers in rolling mills, paper machines, and film production lines are all constant power loads, which can be realized by combining pole-changing motors with frequency converters or combining mechanical speed change with frequency converters.

5. Dedicated variable frequency drive
For injection molding machines, oil pumping units, textile machinery, elevators, fans, water pumps, air conditioners, mining machinery and other fields, you can choose special frequency converters with application expertise in this industry, which often have unexpected effects.