Constant torque load soft start permanent magnet speed regulation control method

Abstract

The invention provides a constant torque load soft start permanent magnet speed regulation control method, and relates to the technical field of permanent magnet speed regulation. The method comprises the following steps: firstly, setting the soft starting time of a motor dragging a constant torque load, and calculating the average acceleration of the motor during soft starting; the permanent magnet speed regulation device is arranged at the maximum air gap position, so that the motor realizes no-load starting; starting the permanent magnet speed regulation device, reducing the air gap of the permanent magnet speed regulation device, and enabling the rotating speed of the output end of the permanent magnet speed regulation device to be greater than 0; calculating the output torque of the permanent magnet speed regulation device, the torque of the constant-torque load equipment and the output rotating speed acceleration of the permanent magnet speed regulation device; pID regulation is carried out, so that the real-time rotating speed acceleration output by the permanent magnet speed regulation device is equal to the average acceleration of the motor during soft starting; and finally, the air gap of the permanent magnet speed regulation device is adjusted, so that the motor reaches the rated rotating speed, and the motor dragging constant-torque load soft start is completed. According to the method, constant-torque load soft start can be ensured, and heavy-load impact on the motor caused by direct start and direct stop of equipment is relieved.

Description

technical field [0001] The invention relates to the technical field of permanent magnet speed regulation, in particular to a soft-start permanent magnet speed regulation control method for constant torque loads. Background technique [0002] With the continuous development of my country's industrial modernization, constant torque equipment such as belt conveyors and scraper conveyors have been widely used. However, in use, it was found that the direct start and direct stop will cause heavy load impact on the motor, which may easily cause equipment failures such as motor overload and burnout, shaft breakage, etc., requiring production to be stopped for maintenance, resulting in serious economic losses. The way to solve the above problems is to change the speed of the motor or the motor through the transmission system through soft start technology, so that the speed of the output end rises slowly with a constant acceleration, so as to achieve soft start and avoid heavy load im...

AI Technical Summary

Problems solved by technology

The electrical stress generated by the frequency converter can easily lead to the failure of large motor bearings. The root cause is that the alternating magnetic flux induces shaft voltage at both ends of the shaft. If the shaft voltage exceeds the breakdown threshold of the oil film, a breakdown current will be generated, causing the bearing raceway to The surface temperature rises, causing spot melting of the raceway, which eventually develops into grooves, leading to bearing failure

In addition, the serious harmonic interference of the frequency converter will also lead to the imbalance of the air gap magnetic field of the motor, aggravate the formation of shaft voltage and the development of breakdown current, and the investment scale of high-power frequency converter is large, so it is necessary to open up a separate site, establish a frequency conversion room and cooling room, additional capital investment

The hydraulic coupling adopts oil medium transmission, the loss of turbulent kinetic energy is serious, and the transmission efficiency is low; when overloaded, oil is injected to protect itself, causing environmental pollution, and the fusible plug needs to be replaced frequently, which is cumbersome to maintain

At the same time, most of the high-power inverters and hydraulic couplings used on site are imported from abroad. Once the equipment fails, the after-sales procedures are complicated and the after-sales cycle is long, making it difficult to ensure continuous and stable production.

CST is a kind of electromechanical equipment with high integration of electromechanical and hydraulic systems. The performance and reliability of the whole machine are high and the operation is complicated. At present, most of them rely on imported equipment. It is difficult for on-site workers to get started, and the later use and maintenance costs are high.

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