The difference between power frequency screw machine and permanent magnet frequency conversion screw machine is mainly reflected in the following aspects:
| power frequency screw machine | permanent magnet variable frequency screw machine |
|---|
| driving mode | the mechanical structure of fixed speed drive is adopted, and the motor is directly driven by power frequency alternating current. | Using frequency conversion technology, the speed and power of the permanent magnet synchronous motor are controlled by the frequency converter. |
| Speed and power regulation | the speed and power are basically fixed and cannot be adjusted according to actual needs. | The speed and power of the motor can be accurately adjusted to meet different gas needs. |
| Energy use efficiency | the structure is simple and stable, but it is relatively low in energy use efficiency, especially in partial load operation. | The structure is complex, but it has higher energy efficiency, especially when operating at partial load. |
| Start mode | usually use direct start or star triangle start mode, start the impact on the power grid. | Using frequency conversion soft start, the impact on the power grid is small when starting, which is beneficial to protect the motor and the power grid. |
| Operation stability | stable performance, low noise, but limited adjustment range. | It not only has high stability, but also has a wide range of adjustment, which can cope with the complex and changeable gas demand. |
| Maintenance | maintenance is relatively simple, but the motor and transmission parts wear. | Due to the precise control of the motor speed and power, the motor and transmission parts wear less, but maintenance requires certain professional knowledge and skills. |
| Applicable Scenarios | it is suitable for occasions where the gas consumption is stable and the air pressure is not high. | It is suitable for occasions with large changes in gas volume and high requirements for gas pressure, such as semiconductor manufacturing, precision machining and other fields. |
| Cost | the initial investment is low, but the long-term operating cost is high. | The initial investment is high, but the long-term operating cost is low due to high energy efficiency. |
Detailed analysis:
driving mode:
- the power frequency screw machine adopts a mechanical structure with a fixed speed, and the motor is directly driven by power frequency alternating current. This method is simple and reliable, but lacks flexibility.
- The permanent magnet frequency conversion screw machine adopts frequency conversion technology, and the speed and power of the permanent magnet synchronous motor are controlled by the frequency converter. This method can accurately adjust the speed and power of the motor according to actual needs, which is more flexible and efficient.
Speed and power regulation:
- the speed and power of the power frequency screw machine are basically fixed and cannot be adjusted according to actual needs. This results in lower energy efficiency at partial load operation.
- The permanent magnet variable frequency screw machine can accurately adjust the speed and power of the motor according to the actual demand to achieve efficient operation. Especially in partial load operation, the energy efficiency advantage is significant.
Energy use efficiency:
- the power frequency screw machine is relatively low in terms of energy efficiency, especially when it is running under partial load.
- The permanent magnet variable frequency screw machine has higher energy utilization rate, especially in the part load operation, the energy efficiency advantage is remarkable. This helps reduce long-term operating costs.
Start mode:
- the power frequency screw machine usually adopts direct start or star triangle start mode, which has a great impact on the power grid when starting.
- The permanent magnet frequency conversion screw machine adopts frequency conversion soft start, which has little impact on the power grid when starting, which is beneficial to protect the motor and the power grid.
Operation stability:
- the power frequency screw machine has stable performance and low noise, but the adjustment range is limited.
- The permanent magnet variable frequency screw machine not only has high stability, but also has a wide range of adjustment, which can cope with the complex and changeable gas demand.
Maintenance:
- the maintenance of power frequency screw machine is relatively simple, but the motor and transmission parts are worn out.
- Due to the precise control of the motor speed and power of the permanent magnet variable frequency screw machine, the motor and transmission parts wear less. However, maintenance requires certain professional knowledge and skills.
Applicable Scenarios:
- the power frequency screw machine is suitable for occasions where the gas consumption is stable and the air pressure is not high.
- Permanent magnet variable frequency screw machine is suitable for large changes in gas volume, high pressure requirements, such as semiconductor manufacturing, precision machining and other fields.
Cost:
- the initial investment of power frequency screw machine is low, but the long-term operation cost is high.
- The initial investment of the permanent magnet variable frequency screw machine is high, but due to the high energy efficiency, the long-term operating cost is low. In the case of long service life of the equipment, the overall cost of the permanent magnet variable frequency screw machine may be more advantageous.
Summary:
the power frequency screw machine and the permanent magnet variable frequency screw machine have their own advantages and disadvantages. In the selection, should be based on the actual gas demand, energy efficiency, operational stability, maintenance costs and long-term operating costs and other factors for comprehensive consideration. For occasions with large air volume changes and high air pressure requirements, permanent magnet frequency conversion screw machines may have more advantages.
