Current control method and device without phase-locked loop of dual-fed induction power generator

Abstract

The invention provides a current control method and device without a phase-locked loop of a dual-fed induction power generator. The method comprises the steps of acquiring a parameter of the dual-fed induction power generator, and performing coordinate conversion to obtain a stator voltage vector U<s Alpha Beta> and a stator current vector I<s Alpha Beta>; performing coordinate conversion on the stator voltage vector U<s Alpha Beta> and the stator current vector I<s Alpha Beta> to obtain a stator voltage vector U<s d q> and a stator current vector I<s d q>; calculating a d-axis instruction and a q-axis instruction of the stator current vector I<s d q> of the dual-fed induction power generator; calculating a rotor voltage instruction U<r d q> under a virtual synchronous rotation coordinate system; performing coordinate conversion on rotor voltage instruction U<r d q> to obtain a rotor voltage instruction U<r Alpha Beta> under a two-phase static Alpha-Beta coordinate system, and further generating a group of pulse width modulation (PWM) signals so as to control a rotor converter of the dual-fed induction power generator. With the technical scheme provided by the invention, the design and implementation process of a control system is simplified, and the adaptability to parameter change of the power generator of the control system is improved.

Description

technical field [0001] The invention relates to the field of doubly-fed induction wind power generator control, in particular to a phase-locked-loop-free current control method and device for a doubly-fed induction generator. Background technique [0002] With the widespread installation and application of doubly-fed wind turbines in wind farms, doubly-fed induction generators are the core unit of the entire power generation unit, and their operation and control technology has been focused on research. At present, there are two main control schemes for doubly-fed induction generators: vector control and direct power control. [0003] Vector control is generally implemented in a synchronous rotating coordinate system. The rotor current is used as the controlled object to construct a corresponding control closed loop. By adjusting the excitation component and torque component of the rotor current, the output of active power, Control of reactive current. Among them, the rotor...

AI Technical Summary

Problems solved by technology

However, current studies have proved that the phase-locked loop will lead to the negative impedance of the output of the converter, and the interaction with the positive impedance of the power grid will cause oscillation, and in severe cases, it will even cause instability.

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