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Practical application of frequency converter system in textile machinery

in recent years, with the continuous improvement of electromechanical integration technology of textile machinery, AC variable frequency speed regulation has become a trend. In most newly developed textile machinery products, almost without exception, AC asynchronous motor variable frequency speed regulation devices are used

1 characteristics of AC variable frequency speed regulation

1.1 reduce power consumption and reduce costs

textile mills cannot do without air conditioning equipment. When the air-conditioning motor is controlled by the frequency converter, the power consumption is reduced and the electricity expenditure is greatly saved. According to the data provided by a company, 12 air conditioners can save more than 240000 yuan of electricity in the whole year, and the unit power consumption of air conditioners has decreased by an average of 6 or 7 percentage points

1.2 the mechanism is simplified and the performance is improved

the synchronous and coordinated operation of multiple motors is realized through the control of PLC programmable controller or industrial computer, and then through the frequency converter. The movement of each mechanism is controlled according to the production process curve, and then the mechanism is simplified. For example, the roving machine uses AC frequency conversion speed regulation, and the cone wheel speed change mechanism is removed, so as to overcome the problem of slipping and inaccurate speed change of the cone wheel speed change belt

for the spinning frame, the forming cam in the forming mechanism is removed by using the frequency converter, which overcomes the phenomenon of peach bottom pause and peach top impact caused by the forming cam. Make the spinning roll in good shape. In order to facilitate the high-speed unwinding of the next process. At the same time, the variable-frequency governor is used to control the speed of 39 main motor to control the number of spindles, so that the spinning speed changes when spinning in large, medium and small yarns, so as to reduce the yarn breakage rate

2 application of AC frequency conversion technology

the AC motors of the textile machinery controlled by the frequency converter are mainly of two types. One is the commonly used Y Series AC asynchronous motor. This kind of motor is mainly used in textile machines with low speed regulation accuracy and small speed regulation range. The other is AC variable frequency speed regulation special asynchronous motor. It is mainly used on machines with high speed regulation accuracy and large speed regulation range

next, we will introduce different forms of frequency converters

(1) open loop control of asynchronous motor with frequency converter and joint development of new energy all aluminum body cars and passenger cars are called v/f form. This method is simple and reliable. However, the speed regulation range is within 10:1, the speed regulation accuracy is 2%~5% lower, and the low-speed performance is not ideal. Therefore, it is mostly used in knitting machines or textile machinery with low requirements

(2) adopt speed sensorless vector control frequency converter. It has excellent low-speed characteristics. The circuit has simple structure and high reliability. At the same time, it also has good addition and subtraction characteristics, torque characteristics and current limitation characteristics. The speed regulation accuracy can reach 0.5% - 1.0%. The speed regulation range is within 20:1. It is more suitable for speed regulation of printing and dyeing machinery

(3) vector frequency conversion with speed feedback is used to control asynchronous motor, and closed-loop frequency conversion speed regulation, also known as AC servo motor. The speed regulation range can reach 100:1. In order to improve the switching frequency of frequency converter, power insulated gate bipolar transistor (IGBT) is used to replace the general high-power transistor (GTR). It can realize high-frequency response, high precision and intelligence. It is suitable for slitting warping machines, sizing machines, heat setting machines and chemical fiber filament spinning equipment with high speed regulation requirements and constant tension and constant linear speed

on some equipment, such as the winding head told by bamag and the hot roller told by dlenes, the required electrical components are integrated with the frequency converter, the control panel and the mechanical part of the winding head, which reduces the volume and enhances the reliability

3 application example of variable frequency governor in textile

experimental data accuracy of variable frequency governor is applied to spinning machinery, which can be said to be applied to almost all processes of machinery. It includes opening and cleaning machine, carding machine, Slitter, comber, drawing frame, roving machine, spinning machine and lojan machine. For weaving machinery, there are sizing machines, warping machines, etc. In addition, a large number of AC frequency converters are also applicable to knitting machines, non-woven fabrics, chemical fiber machinery, printing and dyeing machinery. The following focuses on the roving machine sizing machine

3.1 FA491 high speed roving frame

this is a new type of roving frame developed in China in recent years. The industrial computer, PLC and frequency converter are used to control four motors, which rotate the spindle wing, roller, simple tube and dragon rib lifting and lowering respectively. The cone wheel speed change device and forming device are removed, and the mechanism is simplified. High efficiency, high reliability, low noise, easy to operate and maintain. Process adaptability is good and head breakage is reduced. The highest speed can reach 1500r/min, and new technologies such as man-machine dialogue and automatic positioning of parking wings are realized. It is a high-level roving machine

3.2 GA308 sizing machine

this sizing machine is AC distributed transmission. Among them, the sizing tank, sizing tank and drying drum are driven by AC variable-frequency motor, while the weaving shaft and towing roller are driven by AC servo variable-frequency motor separately. It is applicable to 5 frequency converters, 2 servo controllers and sensors such as pressure, temperature and moisture regain. It is controlled by industrial computer and PLC. It forms a distributed control system. Among them, PLC is used to control the action of the whole machine and the parameters such as moisture regain, the temperature of drying room and pulp tank, and the pressure of pulp roller. When the whole machine is under operation, the bamboo powder mainly loses the control of the low boiling point volatile material controller. This machine has high control accuracy and stable performance. Check whether the intermediate relay is damaged and the failure rate is low. It is a high-quality and high-level equipment

4 prospects for the application of variable frequency governor in textile varieties

the internationalization of China's textile industry is accelerating. However, compared with the international advanced level, there is still a big gap. In order to narrow the gap, we should constantly improve the level of electromechanical integration of textile machinery. The AC frequency conversion technology is better applied to the control of textile machinery

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