Application of Sunwoele VFD (Variable-frequency Drive) in the textile industry
1 Characteristics of AC variable frequency speed regulation
1.1 1 Reduce power consumption and reduce costs
Textile factories cannot do without air conditioning equipment. When the air conditioner motor is controlled by a variable frequency speed regulator, the power consumption is reduced and electricity expenditure is greatly saved. According to data provided by a company, 12 air conditioners can save more than 240,000 yuan in electricity throughout the year, and the electricity consumption of air conditioners has dropped by an average of 6 or 7 percentage points.
1.2 Simplifying the mechanism and improving performance
Through the control of PLC programmable controller or industrial computer, and then through the frequency converter, the synchronous and coordinated operation of multiple motors is realized. The movement of each mechanism is controlled according to the production process curve, thereby simplifying the mechanism. For example, the roving frame uses AC frequency conversion speed regulation and removes the cone wheel speed change mechanism, thus overcoming the problem of slippage of the cone wheel speed change belt and inaccurate speed change.
For the spinning frame, since the forming cam in the forming mechanism is removed by using a variable frequency speed regulator, the phenomenon of pause at the bottom of the peach and impact on the top of the peach caused by the forming cam is overcome. Keeps spun yarn rolls in good shape. To facilitate high-speed unwinding of the next process. At the same time, the frequency converter is used to control the speed of the main motor to control the number of revolutions of the spindle, so that the speed of the spun yarn changes when the yarn is large, medium or small, so as to reduce the yarn breakage rate.
2. Application of AC frequency conversion technology
The AC motors used in textile machinery controlled by VFD (Variable-frequency Drive) are mainly divided into two categories. One type is the commonly used Y series AC asynchronous motor. This kind of motor is mainly used in textile machines that do not require high speed regulation accuracy and have a small speed regulation range. The other type is a special asynchronous motor for AC variable frequency speed regulation. It is mainly used on machines with high speed regulation accuracy and wide speed regulation range.
领英推荐
The following introduces different forms of VFD (Variable-frequency Drive).
(1) The use of VFD (Variable-frequency Drive) open-loop control of asynchronous motor speed regulation is called the V/F form. This method has a simple and reliable circuit. However, the speed regulation range is within 10:1, the speed regulation accuracy is 2% to 5% lower, and the low-speed performance is not ideal. Therefore, it is mostly used on knitting machines or textile machinery with low requirements.
(2) Use speed sensorless vector control VFD (Variable-frequency Drive). It has excellent low speed characteristics. The circuit structure is simple and the reliability is high. At the same time, it also has good acceleration and deceleration characteristics, torque characteristics and current limiting characteristics. The speed regulation accuracy can reach 0.1%. The speed adjustment range is within the range of 20:1. It is more suitable for speed regulation of printing and dyeing machinery.
(3) Use vector frequency conversion control asynchronous motor with speed feedback, closed-loop frequency conversion speed regulation, also known as AC servo motor. The speed adjustment range can reach 100:1. In order to increase the VFD (Variable-frequency Drive) switching frequency, power insulated gate bipolar transistors (IGBTs) are used to replace general high-power transistors (GTR). It can achieve 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 that require high speed regulation, constant tension and constant line speed.
In some equipment, such as Barmag high-speed winding head and DLENES high-speed hot roller and other components, the required electrical components and VFD (Variable-frequency Drive) and control panel are integrated with the mechanical part of the winding head. It reduces the size and enhances the reliability.
3 Application examples of variable frequency speed regulator in textiles
Frequency converter is used in spinning machinery and can