Permanent magnet direct drive wind turbine generator system control method based on neural network direct torque control

Abstract

The invention relates to a permanent magnet direct drive wind turbine generator system control method based on neural network direct torque control, and belongs to the technical field of electrical engineering. According to the method, a neural network direct torque control strategy is adopted, a stator flux linkage neural network is trained offline to approach a relation curve of a stator flux linkage reference value and the electromagnetic torque, variable stator flux linkage reference value control is achieved, and a stator current d-axis component ids of a permanent magnet direct drive type wind driven generator is controlled to be zero; and a stator voltage calculation formula of the permanent magnet direct drive type wind driven generator is discretized, reference values u * s alpha and u * s beta of alpha-axis and beta-axis components of the stator voltage are obtained through calculation, the reference values are modulated through an SVPWM module to generate driving signals to drive a power switch tube of a machine side converter, and the permanent magnet direct drive type wind driven generator is controlled to work. Generator stator side current harmonic distortion and machine side converter energy consumption can be reduced, and it is ensured that the performance of the whole wind turbine generator system is optimal.

Description

technical field [0001] The invention relates to a control method, in particular to a control method for a permanent magnet direct drive wind turbine based on neural network direct torque control, and belongs to the technical field of wind power. Background technique [0002] Permanent magnet direct drive wind turbines usually use back-to-back converters, which include machine-side converters and grid-side converters. The machine-side converters generally use voltage source converters (VSC). In order to improve the quickness of system response, the machine-side converter of permanent magnet direct drive wind turbine usually adopts the direct torque control (DTC) method to control the electromagnetic torque of the generator. The traditional direct torque control adopts the ping-pong control scheme, which is simple and easy to implement, but this method uses a hysteresis controller, so that there is always an error band in the control of the stator flux linkage and electromagne...

AI Technical Summary

Problems solved by technology

The traditional direct torque control adopts the ping-pong control scheme, which is simple and easy to implement, but this method uses a hysteresis controller, so that there is always an error band in the control of the stator flux linkage and electromagnetic torque, resulting in a large amount of harmonic

The harmonics in the stator current make the electromagnetic torque ripple of the generator larger, which will cause additional mechanical vibration and torsional vibration of the wind turbine

In addition, traditional direct torque control cannot maintain the d-axis component of the AC current on the stator side to be zero, which may not only lead to demagnetization of the permanent magnets, but also increase the power loss of the wind turbine unit-side converter itself

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