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Recently, China United Cement Company（CUCC）purchased permanent magnet synchronous motors from our company. As the industry leader, CUCC chooses our company’s permanent magnet synchronous motor as a major trend in energy conservation and efficiency in the cement industry.
At present, current cement plants, regardless of their size, are driven by motors, 90% of which are AC asynchronous motors, and about 70% of them are driven by fans and other loads. A large part of these loads requires speed regulation. At present, the most widely used traditional method to adjust the air volume is to use an electric actuator to adjust the wind deflector, and adjust the required air volume by adjusting the opening of the wind deflector. In the process of adjusting the wind deflector, the speed of the motor remains unchanged, and its output energy does not change. Only the opening of the wind deflector is adjusted to meet the air volume requirements required by the load. According to the law of conservation of energy, when the load requires a small amount of air volume according to the demand of the system, the opening of the windshield will be reduced. At this time, the difference between the output energy of the motor and the energy required by the load will be Wasted and lost in vain. Since the cement plant is a dusty enterprise, even if dust prevention equipment and dust collection measures are used at each dust point, it is difficult to avoid the emission of fine dust. During use, many windshields are affected by the environment and cannot flexibly open and close the damper according to the instructions, and even get stuck in the material during use, which makes it impossible to adjust. People are often required to go up and clean up on-site, which is time-consuming and laborious. It also brings great losses to production, and more importantly, serious energy loss. Coupled with the resistance loss caused by the use of gate control valves, which seriously affects the economic operation of the equipment, it is imperative to improve this adjustment method.
According to statistics, a 5000t/d new dry-process cement production line mainly uses electrical equipment, including limestone mines, raw material grinding, clinker firing, and the main production processes of cement bulk/packaging and shipment, as well as air compressors and water pumps. There are about 1,100 electric motors in auxiliary processes such as stations, water treatment, and mechanical and electrical maintenance. The total installed power is about 57 thousand kW. Among them, the installed power of low-voltage motors is about 22,000 kW. If all “high-efficiency motors” are adopted, the efficiency is increased by 1%, and the annual operating time is calculated at 7,200 hours, which can save about 1.2 million kWh of electricity throughout the year. It is equivalent to saving 440t standard coal and reducing 1140t carbon dioxide emissions.
High-efficiency motors achieve the purpose of improving motor efficiency by effectively reducing their own power consumption. By adopting new motor design, new technology, and new materials, reducing the loss of electromagnetic energy, thermal energy, and mechanical energy, etc., improve output efficiency. Compared with standard motors, the energy-saving effect of using high-efficiency motors is very obvious. Normally, the efficiency can be increased by 4% on average. Compared with ordinary motors, high-efficiency motors use high-quality materials and optimized design to reduce energy consumption by an average of about 20%, while super-efficient motors consume more than 30% less electricity than ordinary motors. High-efficiency motors are more expensive than ordinary Y-series motors. Around 15%-30%. But generally speaking, the investment amount of high-efficiency motors higher than that of ordinary motors can be recovered within 2 years, and it can save power consumption for the company during the entire life cycle. Therefore, it is necessary to use energy-efficient motors.
The current of the permanent magnet synchronous motor produced by our company is only about 65% of that of the ordinary asynchronous motor. The noise of the asynchronous motor is reduced by 20-40dB(A) compared with the same period. The noise index reaches the highest level E. The temperature rise of the motor is also lower than that of the ordinary asynchronous motor. ℃-25℃, the vibration has reached the highest standard S level. The operating temperature of the motor is low, which is better for energy-saving and also prolongs the service life of the matching wires, switches, inverters, bearings, and other parts. The entire motor system enters a virtuous circle, achieving energy saving and efficiency enhancement for the enterprise The role of.
Features of three-phase permanent magnet synchronous motors:
1) high efficiency and energy saving
It can directly replace the three-phase asynchronous motor to realize self-starting; the built-in permanent magnet generates synchronous torque; it has the characteristics of high efficiency, high power factor, and high reliability in the load range of 25%-125%, and the efficiency is better than the general three-phase asynchronous motor 8-20% higher, energy saving of 10-40% can be achieved; power factor higher than 0.08-0.18; compared with asynchronous motors of the same power, the working temperature is lower by 10℃-25℃ under the same environment.
2) high reliability
The permanent magnet synchronous motor rotor is equipped with three-phase rare earth permanent magnet materials. Through the reasonable selection of the permanent magnet working point, it can achieve high magnetic energy product, superior performance, accurate calculation of working temperature and maximum demagnetization point, and the quality control of permanent magnet materials. Process protection avoids the problem of loss of magnetism when the permanent magnet is in use, thereby ensuring that the three-phase permanent magnet synchronous motor can operate reliably in harsh working environments.
3)good stability
When the three-phase permanent magnet synchronous motor is running normally, the permanent magnet on the rotor generates the excitation magnetic field and the rotating magnetic field generated by the three-phase winding maintains a certain power angle and rotates synchronously. This series of motors will not appear when a large load is suddenly added. The power angle oscillates, and it will not lose a step and fail to run, and it will not damage the motor. Strong carrying capacity, fast dynamic recovery time, and high stable operation performance.
4)strong starting ability
Permanent magnet motors above level 4 can be started directly at full load and have strong pull-in synchronization capabilities.
5) strong versatility
This series of motors have strong versatility, and the installation structure, installation dimensions, and protection levels are the same as those of the Y2 and YX3 series motors.
6)low vibration and noise
Small size, low loss, high efficiency, and energy-saving, so the required ventilation volume is reduced. Compared with the asynchronous motor with pass rate, the cooling fan is naturally reduced, so the noise is greatly reduced; at the same time, due to the reasonable design of the motor air gap, the current waveform is good, and the pulsating rotation in the torque and electromagnetic noise is obviously reduced, which is 20-40 dB(A) lower than the general asynchronous motors of the same specification.
7)wide adaptability
This series of motors have complete specifications and wide adaptability. They can be self-starting and directly replace three-phase asynchronous motors. They can also be equipped with frequency converters for step-less speed regulation. The product has high efficiency and superior operating performance in the entire load range. It is the product with the best energy-saving effect. It is suitable for water pumps, fans, compressors, petrochemicals, chemical fibers, textile machinery, transportation machinery, mixers, agricultural machinery, packaging, Transmission equipment in food machinery, papermaking, printing and dyeing, metallurgy, and other industries.
In short, the concept of energy conservation and environmental protection is deeply rooted in the hearts of the people, and the world is committed to the development of energy conservation and environmental protection technology. In an environment where the country vigorously promotes energy conservation and emission reduction, the energy-intensive cement industry has a long way to go. Motors are the largest energy-consuming equipment in the cement industry, and the vigorous application of energy-saving technologies is imperative. Permanent magnet synchronous motors replace other motors on a large scale.
