Quartz stone is an artificial stone made from ground natural quartz and sintered at high temperature. It has the characteristics of
high hardness, wear resistance, acid and alkali resistance, and rich colors. It is often used in interior decoration and building materials.
The quartz stone production process mainly includes six steps: raw material selection, batching, mixing, pressing, solidification and polishing.
Every step of the quartz stone production process needs to be carried out in strict accordance with the operating requirements to ensure
the quality and appearance of the quartz stone. With the continuous development of technology, the quartz stone production process is
also constantly improving to meet the needs of different users for quartz stone.
With its excellent performance, the FR500 inverter can soft-start the motor. The current at startup does not exceed 1.2 times the rated
current of the motor, extending the service life of the motor. The operation stability and safety of the quartz press are greatly improved,
the protection function is powerful, and the ability to adapt to power grid voltage fluctuations is strong. Reduced equipment maintenance
work. The control system customized for quartz presses integrates numerous safety technologies and automatic control functions.
Manufacturers reported that some equipment occasionally had vibration problems during operation, causing the plates to be crushed.
A newly installed unit in a large stone processing factory in Yifeng, Jiangxi Province vibrated 5-6 times a day, and the phenomenon was quite obvious.
（1）Change to vector control F00.08=1，oscillation suppression is effective F09.14=100.0, it is ineffective.
（2）Change the output waveform and harmonic of inverter, change the values of F00.12 and F00.13,it is ineffective.
（3）Increasing acceleration time F03.00,(Because each oscillation starts, it happens in the frequency increasing process),when the factory
default is 15S, the manufacturer has changed to 40S, saying that the oscillation has been reduced. But on the scene, the oscillation is still
obvious, continue to optimize and modify as S curve, so that the acceleration is smoother,F03.10=1,F03.11=5S,it is effective，the oscillation
was reduced from 33% to 10%.
（4）After analysis, the load is a large inertia load, similar to the fan load，to change the F09.00=3 or 4, the normal operating current is
reduced from 40-45A to 30-33A, which can greatly reduce the oscillation frequency, but it is easy to skip the overvoltage failure during the
deceleration, and the process does not allow the growth deceleration time;
（5）F09.00=1,F09.07=25.0,F09.08=40.0,F09.09=45.0,F09.10=60.0,between normal 32-45HZ, it work in the fan curve, when in the low frequency
band, the F09.05=5.0, F09.06=14.0, and large torque load curves are maintained to ensure the starting torque and deceleration but not over
pressure, after revised, there has been a oscillation in the 50 patch(2%).
(6)If it is ineffective to adjust other parameters, continue to observe, basically, each oscillation frequency is 36HZ or above, listen to the sounds,
there was abnormal sound appearing in 36HZ (normal operation)，it is mechanical resonance frequency point, after changing the process
frequency to 35HZ,37HZ,there is no oscillation phenomenon all day.
Because the quartz stone press is the inertia load, the VF curve can be modified to reduce the current, it can reduce oscillation probability
and achieve the effect of saving energy.
When mechanical equipment during manufacturing, there is a resonance point because of the weight, the way of installation and so on,
if the resonance point is in the normal working range of the process, adjust the process as much as possible to avoid the point,it can be
found by noise during normal working at different frequencies.
