High-speed train asynchronous traction motor square-wave single-loop flux weakening control method

Abstract

The invention relates to a high-speed train asynchronous traction motor square-wave single-loop flux weakening control method, which comprises the steps that 1, the maximum voltage U<smax> that an inverter can output is determined; 2, when an asynchronous attraction motor does not enter a square-wave operating condition, d-axis voltage u<sd> equals to u<sd1>, q-axis voltage u<sq> equals to u<sq1>, and when the asynchronous attraction motor enters the square-wave operating condition, the d-axis voltage u<sd> equals to u<sd1>, and the q-axis voltage u<sq> equals to the square root of (U<smax><2>-u<sd1><2>); 3, designing a flux weakening PI regulator according to a current relationship of the d-axis and the q-axis; 4, according to a switching control strategy, adopting a double-current-loop vector control strategy is adopted when the d-axis voltage u<sd1> is greater than the square root of (U<smax><2>-u<sd1><2>), and adopting a square-wave single-loop flux weakening control strategy when the d-axis voltage u<sd1> is less than the square root of (U<smax><2>-u<sd1><2>). The square-wave single-loop flux weakening control strategy is adopted, so that the tracking response capability of the current is improved, and thus the transient response capability of the current is improved; and smooth transition between double-current-loop vector control and square-wave single-loop flux weakening control is realized, and the asynchronous traction motor is ensured to have no current and voltage impact when the control strategy is switched.

Description

technical field [0001] The invention relates to the field of traction motor control, in particular to a square-wave single-loop field-weakening control method for an asynchronous traction motor of a high-speed train. Background technique [0002] In a high-power traction drive system, in order to reduce switching losses and make the inverter more compact and lightweight, the inverter usually enters a square wave working condition after the traction motor enters the field-weakening region to make full use of the DC bus voltage and reduce the inverter load. The switching frequency of the converter. After the traction motor enters the square wave, the amplitude of the fundamental wave voltage remains unchanged, only the vector angle of the fundamental wave voltage is adjustable, while the traditional double current loop vector control strategy needs to keep the amplitude and angle of the stator voltage of the motor under control at any time. If the traditional double current l...

AI Technical Summary

Problems solved by technology

[0007] Aiming at the problems of poor current tracking response ability and voltage mutation during switching in existing control schemes, on the basis of traditional vector control strategies, the present invention provides a square-wave single-loop field-weakening control method for asynchronous traction motors of high-speed trains, mainly The purpose has the following two points:

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