Home > Application > HVAC > H501 Permanent Magnet Synchronous Frequency Conversion in Screw Air Compressor Application


01. Overview

Air compressor is a device that compresses air to increase air pressure. It is the second power source after electricity. It is widely used to drive various pneumatic machinery and pneumatic tools. , textile, petrochemical, light textile and other industries have a wide range of applications, is the key equipment in many technological processes.

The traditional screw air compressor has some obvious technical weaknesses: for example, the air supply volume cannot be continuously adjusted, and the air pressure is prone to large fluctuations; energy is seriously wasted during unloading; frequent start and stop will affect the service life of the motor and require a large amount of equipment maintenance. etc.

In recent years, the speed of the air compressor motor has been changed through the frequency conversion speed regulation technology, and the air supply flow of the air compressor can be adjusted automatically with the change of the air consumption, so as to achieve a real supply and demand balance. The best working efficiency, the frequency conversion screw air compressor has become the development trend of the air compressor market.


02. Advantages of variable frequency screw air compressors

The technical weaknesses of traditional screw air compressor power frequency control and the advantages of variable frequency control:


(1) The control method of adding and unloading to adjust the gas supply is a serious waste of energy

In the traditional control method, when the air compressor is loaded: during the pressurization process from the set pressure to the unloading pressure, electric energy is wasted in vain, and the process of decompression through the pressure reducing valve is also a waste of energy; when the air compressor is unloaded : Close the solenoid valve to keep the motor idling all the time. This adjustment method is also a great waste of capacity, and the power consumption during unloading accounts for about 20% to 40% of the full load.

In the variable frequency control mode, the variable frequency drive system controls the air pressure by controlling the motor speed, so that the output pressure is always maintained at the set pressure, and the output pressure remains constant, avoiding the waste of electric energy caused by frequent loading and unloading.

The air compressor is a constant torque load. In terms of output power alone, the energy saving effect of frequency conversion speed regulation is far less significant than that of the fan pump type quadratic load. However, most of the air compressors are in a long-term continuous operation state. Since the exhaust volume is selected according to the maximum demand in the design, in actual operation, the proportion of the time of non-full-load operation is also very high, and the non-full-load operation process has Huge energy saving space.


(2) The impact of starting current is large

The main motor of the traditional air compressor adopts Y-△ decompression starting, and the starting current is about 3 times the rated current, which is still very large, and has a large impact on the power grid, which is easy to cause grid instability and threaten the operation safety of other electrical equipment.

The inverter can make the current of the motor start and load smoothly rise without any impact; the motor can realize soft start and stop to avoid the harm caused by the impact current, which is beneficial to prolong the service life of the equipment;

(3) Poor air supply pressure stability

In the process of product production, the stability of air pressure has a great impact on product quality. Users have certain requirements on the accuracy of air supply pressure. In order to avoid insufficient air pressure in traditional air compressors, the air supply pressure is higher than the required value. , but this will lead to high cost and high energy consumption, and it is difficult to ensure the air pressure and temperature due to frequent loading and unloading;

The frequency converter can monitor the gas pressure in the gas supply pipeline in real time in a closed loop, and the PID regulator compares the current pressure with the set pressure difference to ensure that the output pressure is always maintained at the set pressure, and the output pressure remains constant, improving production efficiency and product quality.


03. Application of H501 series inverter in air compressor

1. Advantages of the program

Humanized design, easy installation and simple operation;

Protect the motor and prolong the service life of the equipment;

High power factor, small reactive power loss, and obvious energy saving effect;

Stable performance, large starting torque, good environmental adaptability;

Support synchronous and asynchronous control;

2. Wiring: input (main power) R S T , output (motor) U V W

Start signal 10--DI1 11--COM

Fault contact 03--TC1 05--TB1

Communication contact A2--RS+ B2--RS-

3. Inverter built-in parameters:

PP.01 1 Factory reset

P0.10 400 Preset frequency

P0.12 195HZ upper limit frequency (22KW) 266HZ (37KW) 260HZ (45KW---55KW)

P1.00 2 Permanent magnet synchronous motor

P1.01 Motor rated power (according to the motor nameplate)

P1.02 Motor rated voltage (according to the motor nameplate)

P1.03 Motor rated power supply (according to the motor nameplate)

P1.04 Motor rated frequency (according to the motor nameplate)

P1.05 Motor rated speed (according to the motor nameplate)

P1.20 Back EMF setting If not according to 350V

Self-learning: P1.37 is set to 11 (static learning), press ENTER to confirm, then press RUN, and then jump back to 50.00 and the self-learning is successful.

4. Basic parameters:

P0.02 1 terminal command channel

P0.03 9 Communication frequency setting

P0.17 Acceleration time (20 seconds below 45KW, 55KW--90KW 30 seconds, 110KW above 40 seconds)

P0.18 Deceleration time (20 seconds below 45KW, 55KW--90KW30 seconds, 40 seconds above 110KW)

P0.14 Lower limit frequency 40% rated speed

5. Communication setting:

PD.00 5005 baud rate 9600BPS

PD.01 3 The communication method is 8N1

PD.02 1 Inverter communication address

PD.05 31 standard MODBUS protocol

6. Other parameters:

P6.00 1 Free parking

P9.00 1 Allow overload protection

7. On-site pictures


04. Conclusion

The frequency conversion screw air compressor market is constantly expanding, and the domestic frequency conversion screw machine is undergoing the process of popularization. Although the initial investment of the variable frequency screw machine is large, the rate of return is high. With the government's increasing efforts in energy conservation and emission reduction, and the improvement of customers' awareness of energy conservation, it is foreseeable that the frequency conversion screw air compressor will have a high growth potential and a huge market capacity in the future.

In the air compressor market driven by competition, whether an enterprise can effectively improve production efficiency, technology, save energy and reduce consumption so as to reduce production costs has become an important factor for the survival and development of enterprises. Since the H501 series has been introduced to the market, it has greatly improved the production efficiency of manufacturers, ensured the stable operation of the air compressor system, and maximized energy savings and reduced maintenance costs for customers.