摘要(英) |
The solar power systems are mainly fixed-based. In order to enhance the power generation efficiency, the PV module must be kept facing the sun directly at any time. The tracking systems are divided into two kinds of active and passive tracking methods, respectively, the use of photo-sensor and sun trajectory formula to track, and they also have advantages and disadvantages. The photo sensor although have lower cost and less set up precision, but easy to affect the tracking performance by environment and weather. The trajectory formula although doesn’t affect the tracking performance by weather, but the error of mechanism set up should be small and the orientation should be fixed accurately. The mechanism will be aging after using a long time, so the system should be calibrated and maintained usually, and resulting the higher cost.
This thesis proposes the short-circuit current method, it uses the output current of a solar cell as tracking signal, and through the dsPIC to control the sun tracker and achieve the effect of tracking. Thus, the error of mechanism set up and the orientation-fixing accuracy need not to be considered, and the tracking angle that the PV outputs maximum power will still be met. Mix the photo sensor to do the initial position and coarse adjustment to increase the tracking accuracy.
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