How much do you know about the benefits of using VFD (Variable-frequency Drive)?

How much do you know about the benefits of using VFD (Variable-frequency Drive)?

There are many benefits to using VFD (Variable-frequency Drive):

1. The cage-type induction motor which is cheap and easy to maintain is firstly used. Moreover, the original induction motor can be used directly, without the need to modify the machinery and drive system, and improve the mechanical function.

2. Continuous and extensive operations are possible. When using the original common power supply, use another speed change device (reducer, transmission belt, etc.) to change the speed. However, only stepwise shifting can be performed, and continuous shifting cannot be performed.

3. VFD (Variable-frequency Drive) can replace the DC engine, and an induction motor is used at this time. Like DC motors, no brushes, slip-rings, etc. are required, and maintainability and environmental resistance are excellent.

4. VFD (Variable-frequency Drive) can be soft-started and soft-closed, and the acceleration/deceleration time of the engine can be adjusted arbitrarily.

5. Reduce the starting current. Through the soft start and soft close of VFD (Variable-frequency Drive), the starting current can be reduced to 1.5~2 times of the rated current when the motor starts. Generally, when starting straight-in, a starting current 6 times the rated current flows, so that loads are imposed on the frequent operation and stop of the motor.

6. The rebound braking of VFD (Variable-frequency Drive) is convenient for electric braking.

7. One VFD (Variable-frequency Drive) can control several engines in parallel.

8. High operating efficiency.

9. The use of VFD (Variable-frequency Drive) in ventilators and water pumps can save energy; it can be used in air-conditioning equipment to create a comfortable environment.

10. It can run at a high speed above the rated current of the engine.

11. Use optimal speed control to improve quality.

When selecting a VFD (Variable-frequency Drive) configuration, it is necessary to fully grasp the load characteristics, but it is also relatively difficult to do.

1. Confirm the load characteristics such as load type, speed and nature;

2. Confirm whether it is continuous operation, long-term operation, short-time operation and other operating characteristics;

3. Confirm the maximum consumption output value and rated output value;

4. Confirm the maximum number of revolutions and the rated number of revolutions;

5. Confirm the speed control range;

6. Confirm load changes, current, voltage, frequency, temperature changes, etc.;

7. Confirm the required control precision;

8. Confirm the braking method;

9. Confirm the input power configuration. That is, the capacity is selected based on factors such as speed-torque characteristics, overload capacity, time rating, starting torque, rated output value, operation mode, control mode, number of revolutions, efficiency-power, etc.

But it is not easy to select the VFD (Variable-frequency Drive) configuration in the above way. Therefore, ordinary users can choose VFD (Variable-frequency Drive) according to the motor configuration. First, select the configuration voltage (220V, 380V, 440V) and select the VFD (Variable-frequency Drive) capacity according to the engine capacity (kW). Generally, products with low starting torque and load, such as fans and water pumps, use 1:1 capacity engines and VFD (Variable-frequency Drive); for elevators, cranes, etc. that require more torque and large load, select A VFD (Variable-frequency Drive) whose capacity is one stage higher than that of the motor.