以臺大浮台結合15 MW雙饋式感應風力發電機之全機組動態模擬研究

Abstract

本研究使用「臺大浮台(TaidaFloat)」搭載由IEA提供的15 MW風力發電機，進行全機組動態模擬及分析，其中臺大浮台和其繫泊系統為針對台灣海峽環境進行設計的半潛浮動式平台，本研究中亦將UMaine VolturnUS-S作為參考浮台，檢視臺大浮台的可靠度和穩定度。雙饋式感應發電機、併網系統、功率控制系統和葉片變旋角系統等系統之數學模型建立在MATLAB/SIMULINK，風機、浮台及繫泊系統之機械結構在SIMPACK建立，並整合AeroDyn進行葉片和塔柱的空氣動力學分析，HydroDyn進行浮台的水動力分析，MAP++負責繫泊系統分析，並以SIMAT為介面在SIMPACK和MATLAB/SIMULINK之間進行資料傳遞，同步進行全機組的整合模擬。 隨著風機規格日漸龐大，巨大的物理慣性使傳統的PI控制器已無法達到預期的控制目標，浮台本身的俯仰運動亦會使控制結果和預期產生偏差，本研究使用模糊滑動式控制器取代PI控制器，並加入浮台的俯仰角度回授進行運動補償，在各條件下進行模擬分析，包含正常運轉條件和極端條件，檢視系統的穩定性和安全性。 模擬結果顯示當風和波浪為正對風機時，使用臺大浮台和UMaine VolturnUS-S浮台在一般運轉條件發電表現上並無明顯差異，但在惡劣運轉條件和極端條件下，臺大浮台有較優的發電穩定性和運動穩定性。

This study uses "TaidaFloat" semi-submersible floating platform equipped with a 15 MW wind turbine provided by IEA to conduct full set dynamic simulations and analysis. TaidaFloat and its mooring system are designed specifically for Taiwan Strait environment. In this study, UMaine VolturnUS-S is also used as a reference floating platform to examine the reliability and stability of TaidaFloat. The mathematical models of systems such as the doubly-fed induction generator, grid-side converter, power control system, and blade pitch control system are built in MATLAB/SIMULINK. The mechanical structures of the wind turbine, floating platform, and mooring system are built in SIMPACK. They are integrated with AeroDyn for aerodynamic analysis of the blades and tower column, HydroDyn for hydrodynamic analysis of the floating platform, and MAP++ for mooring system analysis. SIMPACK and MATLAB/SIMULINK transfer data through SIMAT interface to perform integrated simulation synchronously. As wind turbines become larger and larger, gigantic inertia make traditional PI controllers can no longer achieve the expected control objectives. Pitch motion of floating platform will also lead to error between the control results and expectations. This study uses a fuzzy sliding mode controller to replace PI controller, pitch angle of floating platform is also added for motion compensation. Simulations and analyses are conducted under various conditions, including normal operation and extreme conditions, to examine system stability and reliability. Simulation results show that when the wind and waves are head-on to the wind turbine, there''s no significant difference in power production performance between TaidaFloat and UMaine VolturnUS-S under normal condition. However, under severe and extreme operation, power production performance and dynamic motions of TaidaFloat are more stable than those of UMaine VolturnUS-S.