Current control device and method for converter, wind power generating set

Abstract

The embodiments of the invention disclose a current control device and method of a converter and a wind generating set. The current control device includes a comparator, a hysteresis regulator and a controller. A first end of the comparator receives a boost current given value of a machine side boost circuit of the converter. A second end of the comparator receives a feedback current value of theconverter. The hysteresis regulator outputs a pulse width modulation (PWM) signal for driving an IGBT in the converter according to a comparison result of the comparator so as to adjust input currentof the converter. The controller is used for adjusting a ring width value of the hysteresis regulator based on the adjusted input current of the converter so as to maintain a ripple value in the adjusted input current of the converter within a predetermined range. The current control device and method of the converter and the wind generating set of the embodiments of the invention is used to avoidthe influence of service life of a generator due to excessive long-term ripple current.

Description

technical field [0001] The invention relates to the technical field of wind power generation, in particular to a current control device and method for a converter, and a wind power generating set. Background technique [0002] The rectified electricity of the wind power generating set needs to be connected to the grid through a converter. When the grid operation is unstable, for example, the grid voltage rises or falls, so that the energy that can be integrated into the grid decreases, but the output power of the wind turbine remains unchanged temporarily, causing fluctuations in the input current of the converter. In order to control the input current fluctuation on the machine side of the converter, a regulator is usually used to adjust the input current of the converter. However, when the output power of the wind turbine is low, the voltage at the generator port in the wind turbine is very low, and the use of a regulator to adjust the input current of the converter will ...

AI Technical Summary

Problems solved by technology

However, when the output power of the wind power generating set is low, the voltage at the generator port in the wind generating set is very low, and the use of a regulator to adjust the input current of the converter will cause the ripple of the input current on the machine side of the converter Larger, the ripple is reflected on the generator as harmonic current, and if the long-term harmonic current is too large, it will seriously affect the service life of the generator

[0003] In the existing technology, in order to avoid seriously affecting the service life of the generator due to excessive long-term harmonic current, it is necessary to increase the filter capacitor to reduce the current harmonic of the generator. However, increasing the filter capacitor will increase the cost and volume of the system, and a large number of harmonics Surge currents can also cause serious EMC problems and reduce operating efficiency

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