What is the application of frequency conversion technology on winding machines

Winding yarn winding machine machine is one of the key production equipment of motor manufacturing enterprises. In production, due to the difference in the form, number of turns, cross-section of the magnet wire, and the number of parallel windings of the shuttle coil, especially the winding of various specifications of motor coils with a large number of varieties and a small number of winding machines is required. The speed adjustable range is large, the adjustment is convenient, and it has relatively stable starting and braking characteristics. It should have enough torque when winding at different speeds. As the frequency conversion speed regulation technology matures, the winding machine has gradually adopted frequency conversion speed regulation instead of the traditional mechanical gearbox speed regulation trend. How to master the characteristics of the application of frequency conversion speed regulation in the winding machine is particularly important to ensure the safety and normal operation of the equipment . And because of its low cost, stepless and smooth speed regulation, and easy maintenance, the AC variable frequency speed regulation scheme has replaced the DC speed regulation system and has become the first choice for speed regulation schemes. Frequency conversion speed regulation is achieved by changing the motor stator power supply frequency to change the synchronous speed.

To make the power supply frequency of the asynchronous motor variable, a set of variable frequency power supply is necessary. Frequency conversion speed control equipment is a frequency conversion power supply device that converts constant voltage and constant frequency power into variable voltage and variable frequency speed regulation. After the AC power is converted into DC by the rectifier bridge, the DC voltage U0 is filtered by the large-capacity capacitor C. The control circuit adopts PWM or PAM to control the turn-on and turn-off of V1—V6 in an orderly manner. The output frequency of U, V, W output terminals can be The tuning is close to the sine wave voltage. The current-limiting resistor plays the role of current sampling. When an over-current condition occurs, the sampling voltage on the current-limiting resistor increases. By setting the protection threshold, various forms of over-current protection can be realized. When the motor is braking, the feedback energy will increase the capacitor terminal U0. By detecting the size of U0, turn on the switch tube V and put in the braking resistor to ensure that the braking feedback energy is consumed on the braking resistor. If the voltage is constant, the magnetic flux  of the motor changes within a considerable range with the operating frequency f, it is very easy to severely saturate the magnetic circuit of the motor, resulting in serious distortion of the excitation current waveform, resulting in a high peak current spike .

Therefore, the frequency and voltage should be changed proportionally, that is, when the frequency is changed, the output voltage of the inverter is controlled to ensure that the V/f is constant, so that the magnetic flux of the motor can be kept constant, avoiding the phenomenon of weak magnetic field and magnetic saturation, and achieving constant Torque speed regulation. The electromagnetic clutch is a connector that transmits the torque of the active side to the passive side. It can be freely combined, disconnected or braked as needed. Due to the use of electromagnetic force to actuate, it is called an electromagnetic clutch or brake. It has a fast response speed. Simple structure and other advantages. According to the requirements for speed, torque, starting characteristics and braking characteristics of the shuttle coil in the winding process and the analysis of the technical parameters and performance of the shuttle coil winding machine used by our department, it is decided to use the frequency converter to wind The wire machine performs speed adjustment and braking, replacing the traditional gearbox speed adjustment.

Since the winding coil requires the spindle to start smoothly and reach the rated speed in the shortest time, after the coil is wound, the spindle speed is required to drop to zero quickly and smoothly, causing the spindle motor to start and stop repeatedly in a short time. Running or forward and reverse operation, so its drive adopts Mitsubishi general-purpose inverter for forward and reverse operation control, and an AC reactor is added to the three-phase AC power input end of the inverter. Its function is to simulate the higher order of the input current. Harmonic, improve and increase the power factor to ensure the safe operation of the inverter. The frequency conversion braking part adopts an energy-consumption braking unit and is equipped with an aluminum alloy housing resistor, so that the regenerative electric energy generated by the motor in the deceleration process can be consumed in the form of heat on the resistor, achieving a good braking effect. The braking resistor with fully sealed filling material and high heat dissipation aluminum alloy shell has strong vibration resistance, heat dissipation and long-term stability, ensuring the normal operation of the inverter when controlling the motor.