Motor system started without reversing

Abstract

The invention provides a motor system started without reversing and relates to the field of motor systems. The invention provides the motor system started without reversing, which is compact in structure, is capable of effectively preventing a motor from reversing when started, and thus effectively and thoroughly solves the bottleneck problem that a three-phase frequency conversion permanent magnet synchronous motor firstly reverses and then rotates forwards and the popularization and application of the frequency conversion speed regulation permanent magnet synchronous motor is restricted. The motor system comprises a frequency conversion speed regulator and a three-phase frequency conversion permanent magnet synchronous motor. The air gap magnetic flux of the three-phase frequency conversion permanent magnet synchronous motor is reasonably controlled, that is to say, when the current of the frequency conversion permanent magnet synchronous motor reaches a rated value, the air gap magnetic flux should be in a saturation state, and then, the constructive deviation of the frequency conversion speed regulator relative to the specific position of a rotor of the three-phase frequency conversion permanent magnet synchronous motor can be limited within +/- 30 deg, so that the permanent magnet synchronous motor is 100% prevented from firstly reversing and then rotating forwards when started.

Description

technical field [0001] The invention relates to the field of motor systems, in particular to the improvement of a three-phase variable frequency permanent magnet synchronous motor. Background technique [0002] At present, in the energy saving and emission reduction and the national implementation of the motor energy efficiency improvement plan, since the permanent magnet motor has the highest efficiency among high-efficiency motors, it can reach level 1 energy efficiency in the GB / 30253-2013 standard, and the power saving rate is also the most obvious. At the same time, it has become a development trend to implement energy-saving transformation by using frequency conversion speed-adjustable three-phase permanent magnet synchronous motors to improve the energy efficiency of motors. Moreover, there are more and more brands of frequency converters suitable for permanent magnet synchronous motors. However, when starting with variable frequency, permanent magnet motors often rev...

AI Technical Summary

Problems solved by technology

Moreover, there are more and more brands of frequency converters suitable for permanent magnet synchronous motors. However, when starting with variable frequency, permanent magnet motors often reverse first (1 / 8 cycle) and then forward, which cannot meet part of the load (such as spinning Machine, two-for-one twisting machine, etc.) process requirements restrict the promotion and application of permanent magnet synchronous motors. In order to solve this technical problem, the one-way coupling scheme is generally adopted at present, that is, a single To the shaft coupling, when the motor reverses, the one-way coupling slips and does not transmit torque. When the motor rotates forward, the one-way coupling outputs torque, and the motor rotates with the load. Using this method, It can prevent the motor from rotating reversely and then forwardly to bring a great impact to the load, but the application practice proves that the service life of the one-way coupling is very short

After 2-3 months, the inner key of the one-way coupling is very easy to be damaged. It is still not an effective solution to use the one-way coupling to try to solve the reverse rotation of the three-phase variable frequency permanent magnet synchronous motor started by frequency conversion.

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