Application of Sunwoele HSF600 vector VFD (Variable-frequency Drive) on sand saw

I. Introduction??

Sand saws are widely used in the stone industry. Almost all stone processing enterprises need sand saws, which have the advantages of fast processing speed and high product quality. There are three major problems in the operation of sand saws that users have been working hard to solve:

(1) How to improve the quality and production efficiency of slabs and reduce losses.

(2) How to save high electricity bills.

(3) How to prolong the service life of the sand saw (overhaul cycle).

Problems existing in the original sand saw electric control system:

(1) Due to the imperfection of the current equipment, the speed of the equipment cannot be adjusted, and the best production efficiency cannot be achieved.

(2) The sand saw motor adopts the star/delta starting mode, the starting current is large when switching, and the impact on the equipment and the power grid is large.

(3) The speed of the equipment cannot be adjusted smoothly, and the processing technology cannot be adjusted according to the material.

2. Design and working principle of sand saw frequency conversion system

Our company adopts HSF600 series high-performance vector VFD (Variable-frequency Drive) to transform the sand saw. By adjusting the running speed of the motor, the sand saw can be started at a low speed when starting, and there will be no current shock to protect the equipment. During normal operation, it runs at high speed to improve production efficiency. When the production is about to end, it runs at a low speed to reduce the chance of pulling the plate. The brake system is used when stopping or emergency stopping to shorten the stopping time. Make the sand saw achieve the best results in different working conditions.

3. The solution and effect of sand saw frequency conversion system

1. Plan:

(1) Speed regulation In addition to not changing the control method of the original equipment, the speed regulation function is added, and it is enough to press it once when starting, and there is no need to start it several times in a row.

(2) Safety Inner network of the power grid: the surge voltage drops significantly, and the inrush current is significantly reduced; the external network of the power grid: good terminal working conditions reduce the load of the external network to the greatest extent.

(3) Consumption reduction Reduce raw material loss and reduce equipment wear and tear.

(4) Energy saving Save energy and reduce power consumption.

2. Effect:

(1) The original operating system and safety protection of the equipment remain unchanged, and frequency conversion is used for speed regulation. Realize processing and cutting according to different materials and different processes to improve the quality and production efficiency of slabs. At the beginning of material cutting, reduce the speed, and then speed up when the sawtooth is completely cut into the stone, so that it is not easy to run the knife, and there will be no waves on the slate. When cutting to the last ten centimeters, reduce the speed so that it is not easy to pull the board. When cutting rotten materials or stones with cracks, reduce the speed and reduce the speed of the knife at the same time. Slower speed can reduce the impact, the stone is not easy to break and pull the board, and the loss is reduced. It can help stone processing enterprises to realize their own unique processing technology technically.

(2) Use VFD (Variable-frequency Drive) to digest the instantaneous surge voltage and surge current generated during the working process of the sawing machine. There are fewer internal network surges and transients, and almost no vibration of other devices. Directly reduce the load of the external network and protect the safety of electricity consumption.

(3) Make the improved process of frequency conversion speed regulation to minimize the loss of raw materials, increase the output rate, reduce the cost and improve the competitiveness. Eliminate the hard start and stop of equipment, reduce the wear of transmission and moving parts, and adjust the speed linearly, so that the lubrication system and transmission and moving parts are warmed up and put into operation synchronously. Thereby prolonging the service life of the equipment, reducing the number of overhauls and improving the utilization rate of the equipment.

(4) Reduce power consumption, save electricity expenses, reduce production costs and increase profits.

(5) Simple maintenance, the machine adopts dust-proof and anti-corrosion design, no special maintenance is required.

4. Problems that should be paid attention to in the transformation of frequency conversion and speed regulation of sand saws

(1) Overcurrent problem: Since the sand saw has a large inertia, the current is relatively large when starting, so when selecting the model, the VFD (Variable-frequency Drive) should be selected with a power level higher than that of the motor.

(2) Overvoltage problem: Since the motor of this equipment is connected to the flywheel through the belt, and then connected to the saw blade through the crankshaft, the flywheel generates a regenerative voltage during operation, resulting in VFD (Variable-frequency Drive) overvoltage protection phenomenon. Prolong the acceleration and deceleration time properly or add braking unit and braking resistor.

5. Wiring diagram

6. Conclusion

To sum up, VFD (Variable-frequency Drive) has great achievements in the application of stone industry. It is the future technology development direction. It not only saves energy, but also has good adjustment performance, which improves product quality and enhances the competitiveness of enterprises.