风力发电机大风限速保护方法的研究

A Study of Wind Speed Limit-related Protection Methods for Wind Turbine Generators During a Gale

小型风力发电机面临的最大难题是其可靠性问题,即大风时的限速保护问题。从能量守恒的角度分析了利用风轮与发电机的功率匹配特性实现风力发电机限速保护的可行性。另外,设计了2台风轮与发电机具有不同匹配特性的300 W/26 V风力发电机,为了使其具有可比性,使用了同样型号的发电机。通过实验测试了风轮的机械输出特性、发电机在输出电压不同时的功率特性和整机的功率输出,实验结果表明,风速12 m/s以下时2台风力机输出功率基本相同,风速12 m/s以上时其中1台随着风速的增加功率不断增加,而另外1台随着风速的增加输出功率不再上升,甚至有点下降,与大风机功率特性相似。

The most difficult problem faced by a small-sized wind turbine generator is the assurance of reliability,i.e.speed limit-related protection problem when a gale takes place.From the standpoint of energy conservation,the authors have analyzed the feasibility of employing the power matching characteristics of a wind wheel and an electric generator to fulfil the speed limit protection of a wind turbine generator.In addition,the authors have designed two sets of 300 W/26 V wind turbine generator,of which the wind wheels and generators have different matching characteristics.To enable them to share an identical base for comparison,electric generators of the same model were used.Through tests,measured were the mechanical output characteristics of the wind wheels,power characteristics of the generators and power output of the whole machine at different output voltages.The test results show that when the wind speed is below 12 m/s,the two wind turbine generators have a basically same power output.When the wind speed is over 12 m/s,one of the two wind turbine generators will increase its power output continuously with an increase of the wind speed,while another will no longer increase its power output with a wind speed increase,but even slightly decrease its power output,similar to the characteristics of a large-sized wind turbine generator.