Self-starting permanent magnet synchronous motor i/f starting method and system

Abstract

The invention discloses a self-starting permanent magnet synchronous motor I / F starting method and system. Before starting the motor, according to the load size driven by the motor, the phase current amplitudes of different stages are set; and the current frequency is set according to the load characteristics. The relationship between the current amplitude and the current amplitude; then calculate the coordinate change angle according to the current frequency; according to the principle of the maximum torque / current ratio and the current amplitude, determine the current given values ​​of the d and q axes; finally, according to the current and the coordinate transformation angle Given the principle, start the motor running process, and the motor can start stably. This starting method can ensure that the torque and load capacity are large in the starting stage, and at the same time ensure that the starting current is not too large; in addition, this method can also change the synchronous speed until the rated speed of the motor is reached, and it is switched to the middle. After high-speed sensorless vector control, operation can be stably switched back and forth.

Description

technical field [0001] The invention relates to the starting technology of a frequent heavy-load starting motor, in particular to an I / F starting method of a self-starting permanent magnet synchronous motor. Background technique [0002] Metallurgy, hoisting and other industries have a large number of constant-speed driving conditions that require frequent heavy-load starts. At present, there are mainly two driving methods: (1) The driving motor (often an asynchronous motor) drives the load through a deceleration transmission chain. This driving mode has large starting torque and small starting current, but the operating efficiency and power factor index are low; (2) The squirrel-cage rotor self-starting permanent magnet synchronous motor is used for load driving. This method can maintain high efficiency and power factor in a wide load range, and has developed rapidly in recent years and has been widely used. [0003] In order to further improve the operating efficiency and...

AI Technical Summary

Problems solved by technology

For example, increasing the motor rotor resistance can increase the starting torque, but it will cause a decrease in the ability to pull in synchronously, and the motor will eventually run in an asynchronous state and cannot be pulled in synchronously

In addition, there is a current impact during the start-up process of the self-starting permanent magnet synchronous motor. When the driving power is large or frequent start-stop, it will have a great impact on the power grid

[0004] It can be seen that the starting ability has become a bottleneck restricting the further promotion and application of self-starting permanent magnet synchronous motors

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