串聯式電壓驟降補償器之負載變壓器湧浪電流抑制方法設計

Design of a Load Transformer Inrush Mitigation Method for the Series Voltage Sag Compensator

林長億(Chang-Yi Lin)

指導教授 ： 鄭博泰

國立清華大學/電機資訊學院/電機工程學系/碩士(2008年)

https://doi.org/10.6843/NTHU.2008.00717

摘要

根據文獻記載，92%的工廠設備停機問題與電壓驟降有關。當電壓驟降發生時，導致生產線上的設備無預警停機，以造成嚴重的經濟損失。為了有效提昇電力品質，以渡過電壓驟降事故，因此串聯式電壓驟降補償器是最符合經濟效益的解決方法之一。
在工業應用上，多數的工業設備前端大都會加裝負載變壓器進行電氣隔離，以保護設備以及維修人員的安全。當電壓驟降發生時，電壓驟降補償器偵測到驟降發生並啟動，此時會造成負載變壓器上之磁通鏈的偏移，而補償瞬間的磁通鏈偏移如超出變壓器磁飽和之操作點，將會引入湧浪電流。而湧浪電流的發生，可能導致驟降補償器之過電流保護動作而失效，進而造成工業設備停機。本文提出一湧浪電流抑制方法結合狀態回授控制器應用於串聯式電壓驟降補償器系統。
本文將以電腦模擬及實際電路實驗結果，驗證所提之湧浪電流抑制方法，並將於後續章節，詳細說明其控制原理。
未來將朝以下兩點來進行：
1.目前本論文所採用的磁通鏈估測器為開迴路的估測，除了需事先測得負載變壓器的電路參數外，隨著負載變壓器的老化或是環境的變化，電路參數也會跟著改變，因此後續將會朝向閉迴路的磁通估測器為走向，隨時修正變壓器的電路參數，以估測出更準確的負載變壓器磁通鏈。
2.針對IEEE P1668 電壓驟降知相關規範的測試規格進行模擬或實測以驗證本文文所提之系統架構能符合此測試的規範。

關鍵字

電壓驟降 ； 湧浪電流 ； 磁通鏈

並列摘要

Survey results suggest that 92% of interruption at industrial facilities is voltage sag related. the unexpected shut-downs of production lines often result in substantial economic losses. Voltage sag compensators, which are connected in series with critical loads, have been considered the most cost-effective ride-through solution against voltage sags.Transformers are often installed in front of critical loads for electrical isolation. When voltage sags happen, the transformers are exposed to disfigured voltages and a DC offset will occur in its flux linkage. When the compensator restores the load voltage, the flux linkage will be driven to the level of magnetic saturation and severe inrush current occurs . The compensator is likely to be interrupted because of its own over-current protection, and eventually the compensation fails, and the critical loads are interrupted by the voltage sag.This thesis proposes an inrush current mitigation technique together with a state feedback controller for the voltage sag compensator. The operation principle of the proposed method is presented in detail, simulation, and experimental results are provided validate the proposed approach.

並列關鍵字

voltage sags ； inrush current ； flux linkage

參考文獻

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