Generator side converter vector control method for direct-drive permanent-magnet synchronous wind power generation system

Abstract

The invention discloses a generator side converter vector control method for a direct-drive permanent-magnet synchronous wind power generation system. The method comprises the steps that a d-axis in a two-phase synchronous rotating coordinate system is oriented in the rotor flux linkage vector psif to form a two-phase synchronous rotating coordinate system (d, q) oriented by the rotor flux linkage vector psif, and a stator voltage vector Vs and a stator current vector Is are oriented in the two-phase synchronous rotating coordinate system (d, q) oriented by the rotor flux linkage vector psif; afterwards, the stator voltage vector Vs and the stator current vector Is in the two-phase synchronous rotating coordinate system oriented by the rotor flux linkage vector psif are secondarily oriented into a two-phase synchronous rotating coordinate system (d', q') oriented by a stator flux linkage vector psis, stator d'-axis current is made to equal zero, and then the mutual independent control, namely decoupling control, over active power and reactive power of a direct-drive permanent-magnet synchronous wind power generator is achieved. According to the method, the problem that the power factors of the generator in the direct-drive permanent-magnet synchronous wind power generation system drop is solved; besides, the algorithm is simple, and implementation is easy.

Description

【Technical field】 [0001] The invention relates to a control method for a wind power generation system, in particular to a vector control method for a machine-side converter of a direct-drive permanent magnet synchronous wind power generation system. 【Background technique】 [0002] The current direct-drive permanent magnet synchronous wind power generation system's machine-side converter control is actually the control of its generator, mainly using the stator d' axis current equal to zero control strategy or unit power factor control strategy. In the stator d' axis current equal to zero control strategy, with the increase of the electromagnetic torque of the generator in the direct drive permanent magnet synchronous wind power generation system, the terminal voltage of the generator increases rapidly, and the power factor decreases. Higher, which increases the cost of the machine-side converter. In the unit power factor control strategy, due to the orientation of the rotor ...

AI Technical Summary

Problems solved by technology

In the stator d' axis current equal to zero control strategy, with the increase of the electromagnetic torque of the generator in the direct drive permanent magnet synchronous wind power generation system, the terminal voltage of the generator increases rapidly, and the power factor decreases. Higher, which increases the cost of the machine-side converter

In the unit power factor control strategy, due to the orientation of the rotor flux linkage, there is a coupling relationship between the active power and reactive power generated by the generator and the stator d-axis current and stator q-axis current, so it is difficult to control the active power and reactive power generated by the generator Power, and determining the reference value of the stator d-axis and q-axis current requires complex calculations

Therefore, it is necessary to solve the problems in the prior art that the power factor of the generator decreases, the capacity of the machine-side converter is too large, and there is a coupling relationship between the active power and the reactive power of the generator.

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