- 學位論文
以同時擾動隨機近似法進行風場永磁同步發電機之最大功率追蹤控制
MPPT control for permanent magnet synchronous generator in wind farm using simultaneous perturbation stochastic approximation algorithm
摘要
本文針對風力發電系統提出最大功率追蹤法則，整體系統架構包含了風力機、永磁同步發電機、三相全橋式整流器、昇降壓直流轉換器和固定負載，並由功率和責任週期比較斜率法，以及同時擾動隨機近似法，進行最大功率追蹤。 於風力發電系統之最大功率應用上，雖然同時擾動隨機近似法和傳統比例積分微分控制，其所調整之輸出控制參數皆為責任週期，但同時擾動隨機近似法，不僅不需設定 、 和 三個參數值，也不需使用到風速計、轉速計和風力機之特性曲線資料，即可使永磁同步發電機運轉於可變速度下之最佳轉速點，因而使風力發電系統發揮最大效能，更降低了系統成本。 根據模擬結果，不論風速如何變化，只要在風力機額定運轉風速區間，藉由本文之最大功率演算法和同時擾動隨機近似法，調整責任週期以間接控制風力發電機轉速，使頂端速度比和效能指數維持在最佳值附近。
並列摘要
This thesis focuses on maximum-power-point-tracking (MPPT) algorithm applying for wind-turbine generator system (WTGS). The system includes the wind-turbine, permanent-magnet synchronous generator (PMSG), three-phase full bridge rectifier, buck-boost converter and fixed load. By using duty cycle slope method, power slope method and Simultaneous Perturbation Stochastic Approximation (SPSA), the maximum power tracking can be achieved. To apply the maximum-power-tracking-algorithm in the wind-turbine generator system, the control parameter is the duty cycle of the converter. SPSA controller does not only need to set up the three parameter values , and , but also does not need anemometer, rotation encoder and characteristics of wind-generator. The proposed method enables the permanent-magnet synchronous generator to operate at variable speeds to achieve good performance. The wind-turbine generator system hence has high efficiency and reduces the system cost. As shown in the Simulation results, no matter how the wind speed changes, the tip speed ratio (TSR) and coefficient power ( ) can be near the neighborhood of the optional values, by varying the rating speed of the wind-turbine via adjusting the duty cycles of converter once the wind-turbine generator is operated in its rated range.