太陽能發電系統主動式孤島偵測技術之研究

A Study on Active Islanding Detection Technologies in Solar Photovoltaic System

蔡東育(Tung-Yu Tsai)

指導教授 ： 楊宏澤

中原大學/工學院/電機工程研究所/碩士(2007年)

https://doi.org/10.6840/cycu200700698

摘要

市電與太陽能光電系統併聯運轉下，當市電發生停止運轉，如太陽能光電系統未能感知市電已斷電，仍成一獨立發電系統時，稱為「孤島運轉」。偵測孤島運轉的方法可分為主動式與被動式兩種，被動式偵測技術依照負載特性存在不可偵測區域；主動式偵測技術則存在量測成本高、造成功率損失及不可偵測等缺點。有鑑於此，本文乃提出非線性跳躍滑差模式頻率位移法改善主動式滑差模式頻率位移法不可偵測之缺點，當滑差模式頻率位移法接近不可偵測條件時，透過產生更大的擾動，以避免穩態情況的發生，此一方法並可改善滑差模式頻率位移法在應用於接近負載穩態情況時偵測時間加長的問題。
為驗證所提孤島偵測技術之可行性，本文以Matlab程式實現孤島運轉模型，用以比較滑差模式頻率位移與本文所提非線性跳躍滑差模式頻率位移法在接近穩態條件下之孤島運轉偵測效能。於模擬測試中，各種電力品質事故干擾亦用以評估本文所提孤島運轉偵測方法。系統實體驗證方面，本文則利用電壓源電流控制反流器，以傳統數位訊號處理器為控制核心，使反流器具孤島偵測能力。經由本文實驗結果得知，以傳統滑差模式頻率位移法在負載穩態條件下，執行孤島偵測時會造成偵測性能不佳，甚至無法偵測的情況發生，而使用本文所提非線性跳躍滑差模式頻率位移法，則證實上述在接近穩態條件時，仍然能夠偵測出孤島運轉的情況。

關鍵字

滑差模式頻率位移法 ； 孤島運轉 ； 電壓源電流控制反流器 ； 穩態條件

並列摘要

In a grid-connected solar photovoltaic (PV) system, as grid is disconnected from the solar PV system, if the disconnection is not detected and the PV system operated independently, it is called “islanding operation”. The detection methods can be categorized into passive and active approaches. The passive detection approaches suffer from the existence of un-detection zone (UDZ). Also, exist the issues of active approaches with high cost, power losses, and un-detection zone in the detection process. Therefore, to improve the UDZ drawbacks of the existing active Slip-Mode Frequency Shift (SMS) method, a nonlinear jumping SMS scheme is proposed in the thesis. In the proposed scheme, more perturbation is introduced to the shifting angel, as the stable operating point is approached in the existing SMS method. The time needed by the SMS method around the stable operating point can also be reduced via the proposed scheme.
To verify feasibility of the proposed islanding detection scheme, the islanding operating models are established to investigate the detection performance of the proposed scheme and existing SMS method around the stable operating point via the simulations in Matlab. In the simulation tests, the environment with various power quality events is included for verification of the proposed islanding detection scheme. In practical experiments, employed is a current-control voltage source inverter with the core of a digital signal processor (DSP) where the islanding detection capabilities are built. The experimental results the detection performance and UDZ of the traditional SMS method are improved by the proposed scheme. It is proved that the proposed detection scheme can still detect the islanding operation around the stable operating point.

並列關鍵字

Slip-Mode Frequency Shift ； stable Operating Point ； Islanding ； Voltage Source Current Control Inverter

參考文獻

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