Development of Intelligent Wind Turbine Generator with Tandem Rotors: Optimization of Wind Rotor Profiles

这种智能型风力涡轮机发电机具有以下特点。(1)两个风转子在低风速下开始旋转，但后风转子逆着前风转子反向旋转。(2)风速的增加使两个转速都增加，并且后风转子在额定风速下达到最大转速。(3)随着风速的增加，后风转子逐渐减速并开始与前风转子同向旋转，输出可以保持恒定。(4)此外，反向旋转使输出更高，即使在风差的情况下。为了得到该机组的最佳型线，在台架试验中考察了双旋转电枢型双馈感应发电机的特性，并在风洞中和CFD中对两个风力转子的叶片型线进行了优化。发电机经验证，该发电机与串联式风力发电机配合使用效果良好。 ...更多信息 二次输出由输入电路即内电枢得到.最佳两风转子直径比在D=（后风转子直径）/（前风转子直径）=1的情况下，输出随后风转子直径的增加而增加。D=0.84以下的后风转子可以在较高风速下沿与前风转子相同的方向旋转，但是D=0.84以上的转子不能响应于风速改变旋转方向。也就是说，最佳比率约为D=0.84.3。两个风转子之间的最佳跨度希望使后风转子尽可能靠近前风转子，以获得富有成效的输出。风轮周围的流动状况子午流速度每通过风轮一次就减小一次。在较高的风速下，后风转子与前风转子以相同的方向旋转，并使气流沿沿着轮毂壁向上游流动。然后，后风轮代替制动器和/或桨距控制，抑制过度旋转。5.最佳叶型的建议为了给后风轮提供足够的风能，前风轮的叶型最好在轮毂侧没有弯度.声学噪声串联风转子的噪声水平大于单个风转子的噪声水平，并且反向旋转运行时的噪声水平大于同方向旋转运行时的噪声水平。随着后风转子直径的减小，噪声降低。少

This intelligent wind turbine generator has the following peculiarities. (1) Both wind rotors start rotating at the low wind speed, but the rear wind rotor counter-rotates against the front wind rotor. (2) The increase of the wind speed makes both rotational speeds increase, and the rear wind rotor reaches the maximum rotational speed at the rated wind speed. (3) With more increment of the wind speed, the rear wind rotor decelerates gradually and begins to rotate in the same direction as the front wind rotor, and the output can be kept constant. (4) Moreover, the counter-rotation makes the output higher even if in the poor wind circumstance. To get the optimum profiles of this unit, the characteristics of the double rotational armature type doubly fed induction generator were examined in the bench tests, and the blade profiles of both wind rotors were optimized in the wind tunnel and by CFD.1. GeneratorIt was confirmed that the generator works well in cooperation with the tandem wind r … More otors and the secondary output can be got from the input circuit, namely the inner armature.2. Optimum diameter ratio between both wind rotorsThe output increases with the increase of the rear wind rotor diameter, under the ratio D=(rear wind rotor diameter)/(front wind rotor diameter)=1. The rear wind rotor under D=0.84 can rotate in the same direction as the front wind rotor at the higher wind speed, but the rotor over D=0.84 can not change the rotational direction in response to the wind speed. That is, the optimum ratio is about D=0.84.3. Optimum span between both wind rotorsIt is desirable to make the rear wind rotor close to the front wind rotor as possible, to get the fruitful output.4. Flow condition around wind rotorsThe meridian flow velocity decreases every through the wind rotor. At the higher wind speed, the rear wind rotor comes to rotate in the same direction as the front wind rotor, and makes the flow runs upstream along the hub wall. Then, the rear wind rotor plays in place of the brake and/or pitch control which suppresses the over rotation.5. Proposal of the optimum blade profileIt is desirable that the blade profile of the front wind rotor has not the camber at the hub side for giving the sufficient wind energy to the rear wind rotor.6. Acoustic noiseThe noise level of the tandem wind rotors is larger than that of the single wind rotor, and the level at the counter-rotating operation is larger than that at the rotating operation in the same direction. The noise becomes lower with the decrease of the diameter of the rear wind rotor. Less