離岸風機塗層健康監測技術之改良研究

離岸風力發電為台灣再生能源中重要的發展項目，離岸風機等海上結構物由於長時間處在高濕度、高鹽度的環境中，導致其金屬部件遭受到嚴重的腐蝕問題，台灣位於副熱帶氣候區，全年均溫偏高，使得離岸風機得面對更為嚴峻的腐蝕問題，因此不僅要給予風機高規格之抗蝕塗層保護，塗層腐蝕監測系統亦顯得格外重要。本論文之主要目的為塗層健康監測技術之改良，前半部份介紹了離岸風機於台灣所需面對的問題以及常見的腐蝕檢測技術，並且回顧了本團隊先前之研發成果：CID、CID 2.0，CID驗證了以分壓公式計算塗層交流阻抗的初步概念，CID 2.0將此概念以FPGA等硬體整合達到微型化。本文提出了以CID 2.0為基礎並加以改良之CID 3.0，CID 3.0的改良分為硬體及軟體兩部份，硬體部份針對參考電阻以及電路板厚度進行更改並透過實驗探討其成效；軟體部份針對電容之虛部阻抗進行分壓公式之改良，並以實驗來驗證改良分壓公式之計算成效。實驗結果證實，藉由將參考電阻從107 ohm提升至108 ohm，讓參考電阻與待測物之間的差距縮小，使CID 3.0能夠量測到4*109 ohm之標準電阻；將電路板厚度由1.6 mm提升至2.4 mm，有效地抑制了漏電流及寄生電容的影響，使CID 3.0之量測標準差下降，顯示出其量測穩定性，因此得以減少取樣次數達到快速量測的功用；經過硬體綜合改良之CID 3.0成功測得4*109 ohm*cm2以上阻抗值之商用塗層，並將標準差降至低於平均值一至二個數量級，能夠提供塗層監測可靠的數據；新穎的改良分壓公式成功改善虛部阻抗所造成的計算誤差，準確地計算出電容性塗層之阻抗值，因此能夠更有效地被利用於塗層早期的阻抗監測工作。藉由連續監測試驗說明CID 3.1具有長期監測塗層健康狀態的能力，因此可以做為塗層健康狀態監測的有利工具。

關鍵字

離岸風機；交流阻抗；防蝕工程；腐蝕監測

並列摘要

In this study, we propose the Coating Impedance Detector 3.0 (CID 3.0), which is an improved version of our previous research CID and CID 2.0. CID verified the concept of voltage divide method we used to calculate the impedance of coating. CID 2.0 integrated the concept with hardware and used FPGA to achieve miniaturization. The improvement of CID 3.0 includes two parts: hardware and software. In hardware part, we try to increase the measuring accuracy and stability by changing hardware specification of reference resistor and thickness of PCB. In software part, a newly designed voltage divide equation is proposed to solve the huge calculate error caused by imaginary impedance of coating when using the original voltage divide equation. The experimental results show that CID 3.0 was able to measure a standard resistor of 4*109 ohm when the reference resistor was increased from 107 ohms to 108 ohms. Increasing the thickness of PCB from 1.6 mm to 2.4 mm can inhibit the influence of parasitic capacitance and leakage current. As the results, CID 3.0 showed a better measurement stability, and the measurement standard deviation of CID 3.0 was decreased. CID 3.0 with both reference resistor and thickness improved can successfully measure commercial coatings with impedance up to 4*109 ohm*cm2, and the standard deviation is reduced to one to two orders below the average. The novel voltage divide equation can accurately calculate the imaginary impedance of the capacitive coating, so it made CID 3.0 a better equipment for early stage coating monitoring.