Dead-time compensation method for inverter of wind turbine

Abstract

A method for compensate dead time of inverter stage of wind generator include that following steps: (1) determining modulation voltage uio accord to expected output voltage uis and zero-sequence voltage uos; 2) aft that dead time is added, the actual output voltage is taken as the modulation voltage uio, and the actual on-time of the switch, i. E. The time Ti 'of the i-phase actual output positivepulse, is obtain; (3) According to the actual on-time and switching period TS of the switch, the actual duty cycle di of the three-phase upper bridge arm of the inverter stage is obtained. By adopting the method of the invention, under the condition of adding a small amount of hardware, the dead-time benefit of the converter can be overcome, the quality of the output voltage and the current can be obviously improved, and the method has remarkable effects on accurately controlling the amplitude of the basic wave of the output voltage of the fan and reducing the harmonic distortion rate.

Description

technical field [0001] The invention relates to the field of wind turbine design control, in particular to a method for compensating the dead time of an inverter stage of a converter of a wind power generator. Background technique [0002] In recent years, with the large-scale development of wind power generation, my country has become the largest country in the world in terms of installed wind power capacity. As the most important part of wind farm construction, wind turbines are not only related to the safe and reliable operation of the wind farm, but also affect the return on investment of the wind farm. In the engineering implementation of the frequency conversion control of the fan dual-stage matrix converter, since the inverter stage of the dual-stage matrix converter must be synchronized with the rectification stage, the inverter stage must be modulated in two stages in a rectification stage modulation cycle, so that in the implementation In the space vector modulati...

AI Technical Summary

Problems solved by technology

In the engineering implementation of the frequency conversion control of the fan dual-stage matrix converter, since the inverter stage of the dual-stage matrix converter must be synchronized with the rectification stage, the inverter stage must be modulated in two stages in a rectification stage modulation cycle, so that in the implementation In the process of space vector modulation, a large number of dead zones are inserted in the inverter stage, which inevitably results in loss of output voltage and distortion of output current.

At the same time, the dead zone compensation based on space vector modulation generally does not consider the tube voltage drop of semiconductor devices; at some boundary positions, it is also difficult to compensate the error voltage vector caused by the dead zone

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