Tiếng Việt
In industrial production activities, air compressors and air compressor systems play a very important role. The demand for use is very high, so the technical experts have designed and installed inverters for air compressors, in order to improve operation ability and save electricity. VPIC will share with you about the installation solution and advantages and disadvantages of installing inverters for air compressors.
1 – Structure of the air compressor
Industrial manufacturing plants use a lot of air compressors. The basic working principle of an air compressor is to convert the kinetic energy of an electric motor into high-pressure compressed air. Based on the principle of operation, air compressors have 3 basic types as follows:
+ Piston air compressor
+ Screw air compressor
+ Centrifugal air compressor
2 – The role of installing inverters for air compressors
The installation of an inverter for the air compressor helps to adjust and expand the compressed air flow by changing the rotational speed of the air pump motor, but the inlet valve does not change. So when the rotation speed of the compressor changes, other characteristics also change, but the resistance of the pipeline remains constant.
As a result, factories have to use a variety of pneumatically operated machines and equipment to be able to operate at maximum efficiency. Since the compressed air flow will increase much and larger than it actually is, it helps to maximize the energy demand.
3 – Advantages and disadvantages of installing inverters for air compressors
3.1 – Advantages
The installation of an inverter for the air compressor helps to save a large amount of power consumption. The inverter is known for its electric energy saving feature of more than 40%, making the pressure stable independent of the gas consumption flow.
Help the air compressor operate smoothly: the inverter helps the air compressor operate more quietly and reduce the starting current. Therefore, power consumption is also reduced in the no-load mode of the air compressor due to the reduction of the rotational speed to the lowest level. And the oil is still circulated to the lubricating positions such as the screw, etc.
The machine pressure is stabilized: When the VSD is integrated, the engine rotation speed is adjusted, the air flow is also adjusted. Pressure and machine flow have a close relationship, helping to stabilize the pressure level according to the consumption load.
When installing an inverter for an air compressor, it will help prolong the life of the machine: Inverter helps air compressor operate stably, thus reducing breakdowns, prolonging service life and saving repair and maintenance costs significantly.
3.2 – Disadvantages
In addition to the benefits mentioned above, inverters for air compressors also have the following limitations:
The machine will work poorly in a few specific environments: in environments with high temperature, water in the engine compartment, etc., the inverter-powered air compressor will work little or no adaptability. With such operating conditions in the pneumatic engine compartment, the power electronics become weak.
When installing an inverter for an air compressor, the repair is more difficult. Because then the machine structure is more complicated, the possibility of damage is higher than that of a conventional air compressor.
The investment in inverters for air compressors accounts for high costs. Depending on the load consumption and the number of air compressor pumps, the payback will be fast or slow.
4 – Some problems when installing inverters for air compressors
4.1 – Inverter control board problem
The most damaged place is the power block and other IC components, which are also very sensitive to fluctuations in the grid power, dusty environment, erratic power grid fluctuations, high temperatures or coastal areas.
When plugged in, open the switch of the compressor inverter, but the motor is not running, the power indicator light is not on. Measuring the output voltage at 3 phases U, V, W is zero and the 3-phase input R, S, T is still enough, then the power block will definitely have a problem. Continue to check that the fuse is not blown, the voltage after the transformer is still there, the rectifier bridge is broken, the diode is broken or the filter resistor is broken.
If installing an inverter for an air compressor, when the power switch is turned on, the fuse is blown immediately, the cause may be due to:
+ AC damaged transformers
+ The line is short-circuited
+ The filter capacitor is shorted
+ Diode rectifier short circuit
Continue to test the inverter in sequence:
+ Coil primary or secondary circuit being touched
+ The noise filter capacitor, filter capacitor DC source being touched, leaks
+ Voltage stabilizer diode exploded
+ Broken rectifier diodes
Finally, check the resistors, paper capacitors, ceramic capacitors. In addition, two sets that are less damaged and if damaged, are difficult to detect are transistors and ICs.
If the power block is not damaged, the signal light is still on but the machine does not work, a failure may occur in the inverter.
4.2 – Sự cố ở mạch động lực biến tần
When installing an inverter for an air compressor, it is possible that the control circuit is still working fine, the switch is turned on and the signal light is still on. But after a few seconds, the inverter heats up and leads to the automatic power-off protection circuit, the signal light also turns off.
The cause is the short circuit in the motor circuit. Based on the printed circuit from the 3-phase source R, S, T to the A-K terminals to find out where is touched.
5 – Air compressors can mount inverter
Screw compressor: The inverter is installed with a capacity equal to the capacity of the motor.
Compressor when Piston: This is a machine that needs large starting torque, high current every time it is started and enough voltage. Therefore, it is necessary to install an inverter for the compressor above the level with the motor to be able to meet the load.
6 – Conclude
Most air compressors in Vietnam are designed with excess load compared to the actual capacity of the plant. So when the machine has enough pressure in the air tank, the steam will be discharged out, while the engine is still operating 100%, thereby wasting power. Therefore, adding an inverter to the air compressor will help save a lot of energy, but also help the machine operate more stable and durable.
Hopefully with the above knowledge sharing, you can choose for yourself the most suitable inverter installation plan for the air compressor. For more information, you can contact us via Hotline: 0896 422 224
