1.1 reduce power consumption and reduce cost
Textile mills cannot do without air conditioning. When the air conditioning motor is controlled by frequency converter, the power consumption is reduced and the power consumption is greatly saved. According to the data provided by a company, 12 air conditioners can save electricity by more than 240000 yuan, and the unit power consumption of air conditioners has decreased by 6 or 7 percentage points on average.
1.2 simplify the mechanism and improve the performance
The synchronous and coordinated operation of multiple motors is realized by PLC or industrial computer control, and then by frequency converter. According to the production process curve, the movement of each mechanism is controlled, and then the mechanism is simplified. For example, the roving frame uses the AC frequency conversion speed regulation, eliminates the cone wheel speed change mechanism, thus overcomes the cone pulley variable speed belt skid speed change inaccuracy question. For the spinning frame, the forming cam in the forming mechanism is removed by using the frequency conversion governor, which overcomes the phenomenon that the peach bottom has a pause and the peach top has an impact caused by the forming cam. It makes the shape of spinning roll good. In order to facilitate the next process of high-speed unwinding. At the same time, frequency converter is used to control the speed of the main motor to control the number of spindles, so that the spinning speed changes in large, medium and small yarns, so as to reduce the yarn breakage rate.
2、 Application of AC frequency conversion technology
The AC motor used in textile machinery controlled by frequency converter is mainly divided into two categories. One is the common Y series of AC asynchronous motor. This kind of motor is mainly used in the textile machine with low speed regulation precision and small speed range. The other is the special induction motor of AC frequency conversion speed regulation. It is mainly used in machines with high speed regulation accuracy and wide speed regulation range. The following describes the different forms of frequency converter.
(1) It is called V / F form to control the speed of asynchronous motor with frequency converter. The circuit is simple and reliable. However, when the speed regulation range is within 10:1, the speed control 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) Speed sensorless vector control inverter is adopted. It has excellent low speed characteristics. The circuit has simple structure and high reliability. At the same time, it has good acceleration and deceleration characteristics, torque characteristics and current limiting characteristics. The speed control accuracy can reach 0.1%. The speed regulation range is within 20:1. It is suitable for the speed regulation of printing and dyeing machinery.
(3) Vector frequency conversion with speed feedback is used to control asynchronous motor, and closed-loop variable frequency speed regulation is also called AC servo motor. The speed regulation range can reach 100:1. In order to improve the switching frequency of the inverter, the 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 sliver warping machine, sizing machine, heat setting machine and chemical filament spinning equipment with high speed regulation and constant tension and linear speed.
In some equipment, such as the winding head of Bamage high speed and the hot roll of dlenes high speed, the required electrical components, frequency converter and control panel are integrated with the mechanical part of winding head, which reduces the volume and enhances the reliability.
3、 Application of frequency converter in textile industry
Frequency converter is used in spinning machinery, which can be said to be applied in almost every process. It includes opening and cleaning machine, carding machine, sliver winder, comber, drawing frame, roving frame, spinning frame and luojian machine. For weaving machinery, there are sizing machine, warping machine and so on. In addition, knitting machine, non-woven fabric, chemical fiber machinery, printing and dyeing machinery are also widely used.
3.1 high speed roving frame
This is a new type of roving frame developed in China in recent years. Industrial control computer, PLC and frequency converter are used to control four motors to rotate the spindle wing, roller, tube and rib respectively. The cone wheel speed change device and forming device are removed and the mechanism is simplified. High efficiency, high reliability, low noise, easy operation and maintenance. The process has good adaptability and reduces breakage. The maximum speed can reach 1500r / min, and new technologies such as man-machine dialogue and parking wing automatic positioning are realized. It is a high level roving frame.
3.2 sizing machine
This sizing machine is AC distributed transmission. The upper trough, lower trough and drying cylinder are driven by AC variable frequency motor, while the weaving shaft and towing roller are separately driven by AC servo variable frequency motor. It is suitable for 5 frequency converters, 2 servo controllers, pressure, temperature and moisture regain sensors. It is controlled by industrial computer and PLC. A distributed control system is constructed. PLC is used to control the operation of the whole machine, moisture regain, temperature of drying room and pulp tank, and pressure of grouting roller. The whole machine is controlled by industrial computer. This machine has high control precision, stable performance and low failure rate. It is a kind of high quality and high level equipment.
4、 Application prospect of frequency converter in textile industry
The internationalization of China's textile industry is speeding up. However, there is still a certain gap with the international advanced level. In order to narrow the gap, we should constantly improve the level of mechanical and electrical integration of textile machinery. AC frequency conversion technology is better applied to the control of textile machinery. The sensorless current vector inverter and the general frequency converter can meet the requirements of 70% ~ 80% of the frequency converter in the textile industry.
