Frequency converter of extrusion blow molding machine

About frequency converter of blow molding machine

Many people know that inverter can save electricity, but do not know why inverter can save electricity, and how much at the same time, is the high frequency or low frequency save more? In the following content, we have sorted out some of the customers mentioned about the inverter problems.

1. If two identical motors are working in the power frequency state of 50 HZ, one uses a frequency converter, one has not, and the speed and torque are in the rated state of the motor, then can the frequency converter still save power? How much can it save?

Answer: In this case, the frequency converter can only change the power factor, and can not save power.

2. If the torque of two same motors does not reach the rated torque of the motor (frequency, speed or the same as 50 HZ), how much power can the one with the frequency converter save?

Answer: If the automatic energy saving operation is used, the frequency converter can operate at this time, which can save part of the electricity, but the power saving is not obvious.

3. Under the same conditions, how much can be saved in the empty load state, and which province is more in these three states?

Answer: drag load no load state does not save much power. For example, I think there is room for discussion about the "closed loop control". The closed loop control is not just the feedback of the speed sensor. The frequency control in vector control is the closed-loop control, and it is the closed-loop control inside the device. V / F control belongs to the open-loop control. In addition, there is the PID regulator feedback control of temperature, pressure, flow and other physical quantities, which is the category of closed-loop control. And they can be achieved through the frequency converter adjustment, so the closed-loop control concept should not be explained so narrow.

It is an indelible fact that a frequency converter can save electricity. In some cases, it can save more than 40% of electricity, but in some cases it is more wasteful than the frequency converter. Frequency converter is through light load step-down to achieve energy saving, drag distance load because the speed is not much change, even if the voltage is reduced, it will not be much, so energy saving is very weak.

But the fan environment is different, when a small air volume is needed, the power opportunity to reduce the speed, we know that the energy consumption of the fan is proportional to the speed of 1.7 power, so the rotation distance of the motor will drop sharply, the energy saving effect is obvious. If we use it on oil Wells, we will waste a lot of electricity because we use the brake resistance on the return trip.

Of course, if the environmental requirements must be speed regulation, the energy-saving effect of the frequency converter is relatively obvious. No speed adjustment occasion frequency converter will not save power, can only change the power factor. As an electronic circuit, the inverter itself also consumes power (about 3-5% of the rated power). A 1.5-piece air conditioner has its own power consumption of 20-30W, equivalent to a long light lamp.
It is true that the frequency converter operates at the power frequency and has the power saving function. But his preconditions are:
1. High power and fan / pump load;

2. The device itself has power saving function (software support);

3. Long-term continuous operation.

These are the three conditions to reflect the power-saving effect. In addition, there is no saving or not saving electricity, there is no meaning. If you do not add the preconditions to say that the inverter power frequency operation energy saving, is exaggerated or commercial speculation. Knowing why, you will skillfully use him to serve for you. Must pay attention to the use of occasions and use conditions to be good and correct application, otherwise it is blindly follow, credulous and "deceived".