In recent years, with the continuous improvement of the mechanical and electrical integration technology level of textile machinery, AC frequency conversion speed regulation has become a trend. In most newly developed textile machinery products, the AC asynchronous motor frequency converter is applied almost without exception.
1. Characteristics of AC frequency conversion speed regulation
1.1 Reduce power consumption and reduce costs
Textile mills cannot do without air conditioning equipment. When the air conditioner motor is controlled by the 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 more than 240,000 yuan in electricity and the average consumption of air conditioners has dropped by 6 or 7 percentage points.
1.2 Simplified organization improves performance
Through the control of PLC programmable controller or industrial computer, the synchronous and coordinated operation of multiple motors is realized by the frequency converter. The movement of the various mechanisms is controlled according to the production process curve, which simplifies the mechanism. For example, the roving frame uses the AC frequency conversion speed regulation to remove the cone wheel shifting mechanism, thereby overcoming the problem that the cone wheel shifting belt slips and shifts inaccurately.
For the spinning frame, the use of the frequency converter to remove the forming cam in the forming mechanism, thereby overcoming the phenomenon that the peach bottom has a pause and the peach top has an impact due to the forming cam. The shape of the spun yarn is good. In order to facilitate high-speed unwinding of the next process. At the same time, the variable speed governor is used to control the shift of the 39th main motor to control the number of revolutions of the spindle, so that the rotation speed of the spun yarn changes during the large, medium and small yarns to reduce the yarn breakage rate.
2. Application of AC frequency conversion technology
There are two main types of AC motors in the textile machinery controlled by the inverter. One type is the commonly used Y series AC asynchronous motor. This type of motor is mainly used in textile machines where the speed regulation accuracy is not high and the speed regulation range is not large. The other type is an asynchronous motor for AC variable frequency speed regulation. The main language is on the machine with high speed regulation accuracy and large speed range.
The different types of inverters are described below.
(1) Controlling the speed of the asynchronous motor with the open-loop control of the inverter is called V/F. This way the circuit is simple and reliable. However, the speed regulation range is within the range of 10:1, the speed regulation accuracy is 2%~5%, and the low speed performance is not ideal. Therefore, it is mostly used in knitting machines or textile machines that are not demanding.
(2) Control the inverter with a speed sensorless vector. It has excellent low speed characteristics. The circuit structure is simple and the reliability is high. At the same time, it also has good addition and subtraction characteristics, torque characteristics and current limiting characteristics. The speed regulation accuracy can reach 0.5%~1.0%. The speed range is within the range of 20:1. More suitable for speed control of printing and dyeing machinery.
(3) Adopt vector variable frequency control asynchronous motor with speed feedback, closed loop variable frequency speed regulation, also known as AC servo motor. The speed range can be up to 100:1. In order to increase the switching frequency of the inverter, a power insulated gate bipolar transistor (IGBT) is used instead of a general high power tube (GTR). High-frequency response, high precision, and intelligence can be realized. It is suitable for slitting warping machines, sizing machines, heat setting machines and chemical fiber spinning machines with high speed requirements and constant tension and constant line speed.
On some equipment, such as the winder told by Barmag and the hot roller told by DLENES, the required electrical components are integrated with the frequency converter and the control panel and the mechanical part of the winder, which reduces the volume. Increased reliability.
3. Application examples of frequency converter in textile
The frequency converter is used in spinning machinery, and it can be said that almost every process is applied mechanically. Including open cleaning machine, carding machine, stripping machine, combing machine, draw frame and roving machine, spinning frame and Luo machine. For the weaving machine, there are sizing machines, warping machines, and the like. In addition, a large number of AC frequency converters are also used in knitting machines, non-woven fabrics, chemical fiber machinery, and printing and dyeing machinery. The following highlights the roving machine sizing machine.
3.1 FA491 high speed over roving frame
This is a new type of roving machine developed in recent years in China. Four industrial motors, PLC and inverter are used to control the four motors, which rotate the flyer, roller, tube and dragon ribs respectively. The cone wheel shifting device and molding device are removed, which simplifies the mechanism. High efficiency, high reliability, low noise, easy to operate and maintain. Good process adaptability and reduced breakage. The highest speed can reach 1500r/min, which realizes new technologies such as man-machine dialogue and automatic positioning of parking wings. It is a high level roving machine.
3.2 GA308 sizing machine
The sizing machine is an AC distributed transmission. The sizing tank, the sizing tank and the drying cylinder are driven by an AC variable frequency motor, and the weaving shaft and the towing roller are separately driven by the AC servo variable frequency motor. A total of 5 inverters, 2 servo controllers, and sensors for pressure, temperature, and moisture regain are available. Controlled by industrial computer and programmable controller PLC. Form a distributed control system. Among them, PLC is used for the whole machine's action and the moisture regain, the temperature of the drying room and the slurry tank and the pressure of the pressure roller. The whole machine is controlled by the industrial computer. This machine has high control precision, stable performance and low failure rate. It is a high quality, high level equipment.
4. Prospects for the application of frequency converters in textiles
The progress of the internationalization of China's textile industry is accelerating. However, there is still a big gap with the international advanced level. In order to narrow the gap, we should continue to improve the level of mechatronics of textile machinery. The AC frequency conversion technology is better applied to the control of textile machinery.
1. Characteristics of AC frequency conversion speed regulation
1.1 Reduce power consumption and reduce costs
Textile mills cannot do without air conditioning equipment. When the air conditioner motor is controlled by the 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 more than 240,000 yuan in electricity and the average consumption of air conditioners has dropped by 6 or 7 percentage points.
1.2 Simplified organization improves performance
Through the control of PLC programmable controller or industrial computer, the synchronous and coordinated operation of multiple motors is realized by the frequency converter. The movement of the various mechanisms is controlled according to the production process curve, which simplifies the mechanism. For example, the roving frame uses the AC frequency conversion speed regulation to remove the cone wheel shifting mechanism, thereby overcoming the problem that the cone wheel shifting belt slips and shifts inaccurately.
For the spinning frame, the use of the frequency converter to remove the forming cam in the forming mechanism, thereby overcoming the phenomenon that the peach bottom has a pause and the peach top has an impact due to the forming cam. The shape of the spun yarn is good. In order to facilitate high-speed unwinding of the next process. At the same time, the variable speed governor is used to control the shift of the 39th main motor to control the number of revolutions of the spindle, so that the rotation speed of the spun yarn changes during the large, medium and small yarns to reduce the yarn breakage rate.
2. Application of AC frequency conversion technology
There are two main types of AC motors in the textile machinery controlled by the inverter. One type is the commonly used Y series AC asynchronous motor. This type of motor is mainly used in textile machines where the speed regulation accuracy is not high and the speed regulation range is not large. The other type is an asynchronous motor for AC variable frequency speed regulation. The main language is on the machine with high speed regulation accuracy and large speed range.
The different types of inverters are described below.
(1) Controlling the speed of the asynchronous motor with the open-loop control of the inverter is called V/F. This way the circuit is simple and reliable. However, the speed regulation range is within the range of 10:1, the speed regulation accuracy is 2%~5%, and the low speed performance is not ideal. Therefore, it is mostly used in knitting machines or textile machines that are not demanding.
(2) Control the inverter with a speed sensorless vector. It has excellent low speed characteristics. The circuit structure is simple and the reliability is high. At the same time, it also has good addition and subtraction characteristics, torque characteristics and current limiting characteristics. The speed regulation accuracy can reach 0.5%~1.0%. The speed range is within the range of 20:1. More suitable for speed control of printing and dyeing machinery.
(3) Adopt vector variable frequency control asynchronous motor with speed feedback, closed loop variable frequency speed regulation, also known as AC servo motor. The speed range can be up to 100:1. In order to increase the switching frequency of the inverter, a power insulated gate bipolar transistor (IGBT) is used instead of a general high power tube (GTR). High-frequency response, high precision, and intelligence can be realized. It is suitable for slitting warping machines, sizing machines, heat setting machines and chemical fiber spinning machines with high speed requirements and constant tension and constant line speed.
On some equipment, such as the winder told by Barmag and the hot roller told by DLENES, the required electrical components are integrated with the frequency converter and the control panel and the mechanical part of the winder, which reduces the volume. Increased reliability.
3. Application examples of frequency converter in textile
The frequency converter is used in spinning machinery, and it can be said that almost every process is applied mechanically. Including open cleaning machine, carding machine, stripping machine, combing machine, draw frame and roving machine, spinning frame and Luo machine. For the weaving machine, there are sizing machines, warping machines, and the like. In addition, a large number of AC frequency converters are also used in knitting machines, non-woven fabrics, chemical fiber machinery, and printing and dyeing machinery. The following highlights the roving machine sizing machine.
3.1 FA491 high speed over roving frame
This is a new type of roving machine developed in recent years in China. Four industrial motors, PLC and inverter are used to control the four motors, which rotate the flyer, roller, tube and dragon ribs respectively. The cone wheel shifting device and molding device are removed, which simplifies the mechanism. High efficiency, high reliability, low noise, easy to operate and maintain. Good process adaptability and reduced breakage. The highest speed can reach 1500r/min, which realizes new technologies such as man-machine dialogue and automatic positioning of parking wings. It is a high level roving machine.
3.2 GA308 sizing machine
The sizing machine is an AC distributed transmission. The sizing tank, the sizing tank and the drying cylinder are driven by an AC variable frequency motor, and the weaving shaft and the towing roller are separately driven by the AC servo variable frequency motor. A total of 5 inverters, 2 servo controllers, and sensors for pressure, temperature, and moisture regain are available. Controlled by industrial computer and programmable controller PLC. Form a distributed control system. Among them, PLC is used for the whole machine's action and the moisture regain, the temperature of the drying room and the slurry tank and the pressure of the pressure roller. The whole machine is controlled by the industrial computer. This machine has high control precision, stable performance and low failure rate. It is a high quality, high level equipment.
4. Prospects for the application of frequency converters in textiles
The progress of the internationalization of China's textile industry is accelerating. However, there is still a big gap with the international advanced level. In order to narrow the gap, we should continue to improve the level of mechatronics of textile machinery. The AC frequency conversion technology is better applied to the control of textile machinery.
Zhenxing Drying Equipment Co., Ltd , http://www.cz-dryer.com