By
The requirements of the screw extrusion machinery for the motor system are low speed and large torque output. However, the current motor system commonly used in screw extrusion machinery is composed of a motor, a frequency converter, and a deceleration mechanism, which has low efficiency, small speed regulation range, large power consumption, and insufficient response to load changes, leading to the uneven thickness of the blown film, the cumbersome regular maintenance of the reduction mechanism, and the dirty working environment caused by the leakage of the lubrication oil of the reduction mechanism during the production process.
Enneng permanent magnet motor system uses low-speed, high-torque motor and controller to replace the original motor and frequency converter, cancels the reducer in the original transmission mechanism, simplifies the mechanical structure of the system, and makes up for the above shortcomings, making the new type of machinery made great progress in terms of technical content and processing technology, which not only meets the requirements of customers, but also greatly improves in terms of energy saving, simplification of mechanical maintenance, and improvement of working environment, which improves the product competitiveness.
The fundamental frequency of the motor is the highest point of efficiency and output torque in frequency converter speed regulation. According to its characteristic curve, the output torque and efficiency decrease below the fundamental frequency. Therefore, in order to ensure sufficient output torque at low speeds, the motor power must be increased. The Enneng controller maintains a constant torque output below the fundamental frequency of the motor, and has an overload capacity of three times the rated torque. Therefore, it can be ensured that the output torque is not less than the rated torque between the lower rated speed and the zero speed. According to the torque drop curve of the motor when the frequency converter controls the low speed, the servo controller can reduce the motor power to 1/2~2/5 of the frequency conversion control.
If a frequency converter is used to drive a low-speed high-torque motor, due to its small speed regulation range and sufficient low-speed torque, it will not work well at low frequencies. Below 8 Hz, the torque is clearly insufficient. The Enneng controller has a speed regulation range of 0 to 400Hz, and has good low-frequency torque characteristics, which can control the motor smoothly and accurately at low speed. For equipment that has strict requirements on film thickness, such as film blowing machines, the motor can be precisely controlled, which has great technical advantages compared with frequency converters.
