Energy saving equipment suppliers remind you that the application of frequency converters is becoming increasingly popular, and frequency converter speed regulation can be applied in most motor drive scenarios. Due to its ability to provide precise speed control, it can easily control the up, down, and variable speed operation of mechanical transmission. The application of frequency conversion can greatly improve the efficiency of the process (variable speed does not rely on mechanical parts), and at the same time, it can be more energy-efficient than the original constant speed running motor.
1. Control the starting current of the motor
When the motor is directly started through power frequency, it will generate 7 to 8 times the rated current of the motor, which will greatly increase the electrical stress on the motor winding and generate heat, thereby reducing the life of the motor. Variable frequency speed regulation can start at zero speed and zero voltage (or increase torque appropriately). Once the relationship between frequency and voltage is established, the frequency converter can drive the load to operate in V/F or vector control mode. The use of variable frequency speed regulation can significantly reduce the starting current and improve the winding capacity. The most direct benefit for users is that the maintenance cost of the motor will be further reduced, and the lifespan of the motor will correspondingly increase.
2. Reduce voltage fluctuations in power lines
During the power frequency starting of the motor, as the current increases dramatically, the voltage also fluctuates significantly, and the magnitude of the voltage drop will depend on the power of the starting motor and the capacity of the distribution network. Voltage drop will cause voltage sensitive equipment in the same power supply network to malfunction, trip, or malfunction, such as PCs, sensors, proximity switches, and contactors, all of which will operate incorrectly. After adopting variable frequency speed regulation, as it can gradually start at zero frequency and zero voltage, it can eliminate voltage drop to the greatest extent possible.
3. Lower power required for startup
The power of a motor is directly proportional to the product of current and voltage, so the power consumed by a motor that starts directly through power frequency will be much higher than the power required for variable frequency starting. In some operating conditions, the power distribution system has reached its maximum limit, and the surge generated by the direct power frequency starting motor will have a serious impact on other users on the same network. If a frequency converter is used for motor start stop, similar problems will not occur.
4 controllable acceleration functions
Variable frequency speed regulation can start at zero speed and accelerate uniformly according to the user's needs, and its acceleration curve can also be selected (linear acceleration, S-shaped acceleration, or automatic acceleration). When starting through power frequency, it will cause severe vibration to the motor or connected mechanical parts such as shafts or gears. This vibration will further exacerbate mechanical wear and tear, reducing the lifespan of mechanical components and motors. In addition, variable frequency starting can also be applied to similar filling lines to prevent bottles from tipping over or being damaged.
5 adjustable operating speeds
The use of variable frequency speed regulation can optimize the process and quickly change according to the process. It can also achieve speed changes through remote control of PLC or other controllers.
6 Adjustable Torque Limits
After variable frequency speed regulation, corresponding torque limits can be set to protect the machinery from damage, thereby ensuring the continuity of the process and the reliability of the product. The current frequency conversion technology enables not only adjustable torque limits, but even torque control accuracy to reach around 3% to 5%. In the power frequency state, the motor can only be controlled by detecting the current value or thermal protection, and cannot set precise torque values to operate like in variable frequency control.
7 controlled stopping methods
Just like controllable acceleration, in variable frequency speed regulation, the stopping mode can be controlled and there are different stopping modes to choose from (deceleration parking, free parking, deceleration parking+DC braking). Similarly, it can reduce the impact on mechanical components and motors, making the entire system more reliable and increasing its lifespan accordingly.
8 Energy saving
The use of frequency converters in air compressors can significantly reduce energy consumption, which has been demonstrated in engineering experience. Due to the fact that the final energy consumption is proportional to the motor speed, adopting frequency conversion results in a faster return on investment.
9 Reversible operation control
In frequency converter control, there is no need for additional reversible control devices to achieve reversible operation control. Only the phase sequence of the output voltage needs to be changed, which can reduce maintenance costs and save installation space.
10. Reduce mechanical transmission components
Due to the current vector control frequency converter combined with synchronous motor, efficient torque output can be achieved, thereby saving mechanical transmission components such as gearboxes, ultimately forming a direct variable frequency transmission system. This can reduce costs and space, and improve stability.