Wind-speed and rotating-speed sensorless full-wind-speed control strategy for fixed propeller-pitch variable speed permanent magnet synchronous wind generator set

Abstract

The invention relates to a wind-speed and rotating-speed sensorless full-wind-speed control strategy suitable for a small and medium sized fixed propeller-pitch variable speed permanent magnet synchronous wind generator set, and belongs to a master control system in the wind power generating control technology. The control strategy provided by the invention mainly comprises firstly, maximum power tracking control in low wind-speed area; secondly, constant power control in high wind-speed area (above rated wind speed); and thirdly, constant rotating-speed soft transition control between the maximum power tracking control and the constant power control. The realization of the control strategy is based on feedback of DC bus-bar voltage signals and DC bus-bar current signals; required DC bus-bar voltage reference value is given according to the change situations of the detected DC bus-bar current, so as to achieve the purpose that output power of the generator set is controlled by controlling the rotating speed of the generator set. Therefore, wind speed and rotational speed signals are not required to be detected in the control strategy, an expensive wind-speed and rotating-speed sensor can be saved, and accordingly, the control cost is greatly reduced, and the strategy has a good application prospect in the small and medium-sized wind generator sets below megawatt class.

Description

technical field [0001] The invention relates to a main control system within the full wind speed range of a fixed-pitch variable-speed wind power generator set using a permanent magnet synchronous generator, which realizes maximum power tracking control and high wind speed control of the unit in a low wind speed area (below the rated wind speed). The constant power control in the zone (above the rated wind speed) and the constant speed soft transition process between the two operating modes. technical background [0002] As the fastest growing renewable energy, wind energy has become an important means to deal with energy crisis and environmental pollution, and it is the focus and hotspot of current research at home and abroad. Although wind turbines (hereinafter referred to as wind turbines) are gradually developing in the direction of high power, variable pitch and variable speed, almost all wind turbines above the megawatt level have adopted this structure. However, due ...

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Problems solved by technology

Because the pitch angle is fixed, it is very difficult to control the constant power operation of the unit above the rated wind speed, and there are few related control strategies reported at home and abroad.

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