Do you know the reason why Fuling inverter is applied to the crane?
The following example illustrates the use of frequency control for 10 reasons to explain Fuling InverterBasic knowledge applied to cranes:
(1) Control the starting current of the motor
When the motor is directly started by the power frequency, it will generate 7 times to 8 times the motor rating. Current. This current value will greatly increase the electrical stress of the motor windings and generate heat. Thereby reducing the life of the motor and the variable speed can be started at zero speed and zero voltage (of course, the torque can be appropriately increased). Once the relationship between frequency and voltage is established, the inverter can drive the load to work according to V/F or vector control. The use of variable frequency speed regulation can fully reduce the starting current and improve the winding endurance. The direct benefit of the user is that the maintenance cost of the motor will be further reduced and the life of the motor will increase accordingly. (2) Reducing power line voltage fluctuations When the motor power frequency is started, the current will increase sharply while the voltage will fluctuate greatly. The magnitude of the voltage drop will depend on the amount of power that starts the motor and the capacity of the distribution network. A voltage drop will cause a voltage-sensitive device in the same power supply network to trip or malfunction abnormally. If it is close to the proximity and the contactor, it will malfunction. The use of variable frequency speed regulation can gradually eliminate the voltage drop because it can be started gradually at zero frequency and zero voltage. (3) The power required at startup is lower
The motor power is proportional to the product of current and voltage, The power consumed by the motor directly started by the power frequency will be much higher than the power required for the inverter start. In some working conditions, its power distribution system has reached a high limit, and the surge generated by its direct power frequency starter motor will have a serious impact on other equipment on the same network, and will be warned by the grid operator. even fine. If the inverter is used to start and stop the motor, no similar problem will occur. (4) Controllable acceleration function The variable frequency speed control can be started at zero speed and smoothly according to the user's needs. Acceleration, and its acceleration curve can also be selected (linear acceleration S shape acceleration or automatic acceleration) . When the power frequency is started, the motor or the connected mechanical part shaft or gear will produce severe vibration. This vibration will further exacerbate mechanical wear and tear and reduce the life of mechanical components and motors. In addition, variable frequency start-up can also be applied to similar filling lines to prevent the bottle from falling over or being damaged. (5) Adjustable operating speed
Using variable frequency multi-speed speed regulation can optimize the process and can be based on the process Change quickly. Speed changes can also be achieved via PLC or other controllers. (6) Adjustable torque limit
After frequency control, the corresponding torque limit can be set to protect The machine will not be damaged. Thereby ensuring the continuity of the process and the reliability of the product. The current frequency conversion technology makes it possible to achieve not only the torque limit but also the torque control accuracy. In the power frequency state, the motor can only be controlled by detecting the current value or thermal protection, and it is not possible to set an accurate torque value as in the inverter control.
(7) Controlled stop method
Like controllable acceleration, in variable frequency speed regulation , The stop mode can be controlled and there are different stop modes to choose from (deceleration parking free stop deceleration stop DC braking). It also reduces the impact on mechanical components and motors, making the entire system more reliable and with a correspondingly longer life. (8) Energy saving
Energy saving, the starting current, braking, acceleration, deceleration, etc. of the frequency conversion speed regulation, the motor running current is small. In the case of the same production conditions, power consumption and maintenance costs are about 20% higher than the power frequency. (9) Reversible Operation Control
To achieve reversible operation control in inverter control without additional reversible control device only need to change The phase sequence of the output voltage can be changed, which can reduce maintenance costs and save installation space. (10) Reducing mechanical transmission parts Because of the current vector control inverter plus synchronous motor can achieve efficient torque Output, which saves mechanical transmission components such as gearboxes to form a direct variable frequency drive system, thereby reducing cost and space, and improving stability. The control not only improves the safe running time of the lifting equipment, but also greatly reduces the maintenance cost of the work labor maintenance strength. Therefore, the application of the frequency conversion speed regulation technology on the crane is to improve the work efficiency and reduce the energy consumption and ensure the safety of work.
