在電力系統中，濾波器用以消除諧波或是雜訊，被動式濾波器有許多類型，包含L濾波器、LC濾波器、LCL濾波器，其中以LCL濾波器最能有效消除諧波，但是缺點為在控制策略上會較複雜。利用數位訊號處理器晶片可以實現各種控制器，但是，訊號的取樣轉換可能會導致時間的延遲，使得控制器設計更加困難。本文利用LCL濾波器電容器之電流觀察器加到控制迴圈內，不僅能夠減少感測器的數量，而且能夠改善由時間延遲所造成的系統不穩定性。
本文利用Simulink建構出單相轉換器經由LCL濾波器連接電網，並模擬訊號發生時間延遲的情況，再將觀察器加入控制迴圈內，觀察不穩定的波形是否能在啟動觀察器時獲得改善。

In the power system, the filter is often used to eliminate harmonics or noise. There are many types of filters, such as L filters, LC filters, and LCL filters. We use LCL filter to effectively eliminate harmonics, but its disadvantage is that the control would be more complicated. Usually, we use the single-chip like DSP to achieve our control to our system. However, it may result in a time delay because of the signal sampling and conversion, which would deteriorate the power quality. In order to solve the situation, we can use observer into our control loop. It can not only reduce the number of sensors, but also improve the quality of electricity and system instability caused by a time delay.
In this thesis we use Simulink to construct a single-phase converter which is connected to a grid via an LCL filter. We also simulated the situation that the time delay of the signal occurs, and then put the observer into our control loop. We can check that whether the unstable waveform caused by time delay can be improved when the observer is used.

目錄
摘要 I
Abstract II
誌謝 III
目錄 IV
表目錄 V
圖目錄 VI
第一章 1
緒論 1
1.1 研究背景與動機 1
1.2 文獻回顧 1
1.3 論文主要貢獻 3
1.4 論文內容概述 3
第二章 4
電壓源型轉換器與LCL濾波器 4
2.1 前言 4
2.2 電壓源型轉換器(Voltage-Sourced Converter) 4
2.2.1 電壓源型轉換器介紹 4
2.2.2 波寬度調變介紹(Pulse Width Modulation,PWM) 5
2.3 LCL濾波器 5
2.3.1 濾波電容C設計 7
2.3.2 轉換器側電感L1設計 11
2.3.3 電網側電感L2設計 11
2.2.4 濾波器設計 12
2.4 本章結論 13
第三章 13
控制器之數位控制 13
3.1 前言 13
3.2 控制策略 14
3.2.1 電容電流觀察器 15
3.2.2 回授控制器設計 18
3.3 本章結論 19
第四章 19
模擬結果 19
4.1 前言 19
4.2 模擬 20
4.2.1 內迴圈增益kc比較 20
4.2.2 N(s)之不同控制器頻率圖比較 22
4.2.3 相位落後補償器k(s) 24
4.2.4 觀察器模擬 26
第五章 29
結論與未來展望 29
參考文獻 30




表目錄
表 2.1各種濾波器比較表 6
表 4.1模擬參數 20






















圖目錄
圖 2.1系統架構圖 4
圖 2.2 LCL濾波器 5
圖 2.3 LCL濾波器和L濾波器波德圖 7
圖 2.4檢測轉換器側電流i_L1以及電容電壓v_c 8
圖 2.5檢測電網側電流i_L2以及電容電壓v_c 9
圖 2.6檢測電網側電壓v_s以及電網側電流i_L2 10
圖 2.7檢測電網側電壓v_s以及轉換器側電流i_L1 10
圖 3.1轉換器單相等效電路 14
圖 3.2單相控制方塊圖 15
圖 3.3電容電流迴路含時間延遲補償狀態觀察器 18
圖 4.1 kc=1的根軌跡圖 21
圖 4.2 kc=2的根軌跡圖 22
圖 4.3 kc=3的根軌跡圖 22
圖 4.4 kc=3,k=2之N(s) 23
圖 4.5 kc=2,k=2之N(s) 24
圖 4.6 kc=2,k=3之N(s) 24
圖 4.7無落後補償器之波德圖 25
圖 4.8有落後補償器之波德圖 26
圖 4.9單相inverter模擬圖 27
圖 4.10電感電流L1 28
圖 4.11輸出電流L2 28

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