臺灣博碩士論文加值系統

本文主旨為應用於交流微電網之單相逆變器並聯操作的無通訊型分流與穩壓控制。垂降控制可達到無通訊下的逆變器並聯操作，然而功率、電流分配性能受限於穩壓規格，易受傳輸線阻抗與逆變器輸出阻抗不確定性影響，且頻寬低於輸出電壓頻率，無法控制與分配整流性負載諧波電流。為解決上述問題，分流控制器將垂降控制加入虛擬阻抗迴路來控制逆變器輸出阻抗，且阻抗型態選擇適合低電壓微電網應用的虛擬電阻，以降低傳輸線電阻不確定性之影響，分流控制參數可依上層監控系統的功率分配命令修改，達到不同比例的功率分配。穩壓控制器追隨分流控制器產生的電壓命令，其頻寬越高則虛擬阻抗迴路頻寬也能跟著提高，使整流性負載、電阻負載切換等劇烈電流變化之測試條件下的循環電流降低。穩壓控制器採用雙迴路控制架構，內迴路採用預測型電流控制器達到快速響應，外迴路電壓控制器採用相位領先結合比例諧振控制，達到高頻寬與高準度之穩壓。虛擬電阻設計須在穩壓與分流性能間取捨，在傳輸線電阻比例差五倍且標么值必須低於5%之測試條件下，模擬與分析結果驗證虛擬電阻與穩壓性能、循環電流之量化關係，利用此關係可在穩態誤差20%且THDv<3%規格限制下，設計虛擬電阻以最小化循環電流。實驗以四台90W之單相逆變器實驗模組組成並聯系統，設計之控制器以德州儀器製造的TMS320F28379D DSP實現，實驗比較設計之虛擬電阻與未加虛擬電阻之性能差異，加入設計之虛擬電阻後，電阻負載0%切換100%之循環電流暫態峰值由額定電流峰值的33%降至11%，降低3倍且維持相同電壓暫態性能，100%負載穩態響應之循環電流有效值由額定電流的30%降到12%，且穩態誤差18%符合20%規格，整流性負載測試的循環電流則由額定電流的11%降至7%，且THDv=2.8%符合3%規格。因此在設計之穩壓控制、垂降控制基礎上設計之虛擬電阻迴路可在滿足穩壓規格前提下使循環電流在穩態與暫態方面皆能符合設計要求。

The purpose of this research is to develop the communication-less power sharing controller and voltage controller of parallel connected single-phase inverters for AC microgrids. Droop control allows parallel operation of inverters without communication. However, its power and current sharing can be easily affected by the uncertainty of the transmission line impedances and the inverters output impedances. And its bandwidth is lower than the output voltage frequency, so it is impossible to control the harmonic current sharing of the rectifier load. To solve above problems, the power sharing controller adds a virtual impedance loop to the droop controller to control output impedance of inverter, and the virtual impedance type selects a virtual resistor suitable for low-voltage microgrid applications to reduce the line resistance uncertainty. The control parameters can also be modified according to the power sharing command from the upper layer supervisory system to achieve different power sharing ratio. The voltage controller follows the voltage command from power sharing controller. The higher the voltage controller bandwidth, the higher the virtual impedance loop bandwidth, the lower the circulating current under the test conditions of severe current changes such as rectified load and resistive load changing. The voltage controller adopts two-loop control architecture. The inner loop uses a predictive current controller to achieve fast response, and the outer loop voltage controller uses phase lead cascaded PR controller to achieve high bandwidth and high accuracy voltage regulation. The design of virtual resistance must be a trade-off between voltage regulation performance and power sharing performance. Under the testing conditions where the transmission line resistances rato is five times different and the per unit value should be less than 5%, simulation and analysis results verify the quantitative relationship between virtual resistance, voltage regulation performance, and circulating current. Using this relationship, the virtual resistance can be designed to minimize the circulating current under the specifications of steady-state error 20% and THDv<3%. The controller of the experiments is implemented using TMS320F28379D DSP manufactured by Texas Instruments and four 90W single-phase inverters are used to set up the four inverter parallel system. The experiment compares the performance difference between the designed virtual resistor and without virtual resistor. After adding the designed virtual resistance, in 0%~100% resistive load changing test, the circulating current transient peak value is reduced from 33% of the rated current peak value to 11%, which is reduced by 3 times while maintaining the same voltage transient performance. In 100% resistive load steady-state response, the root mean square value of circulating current is reduced from 30% of the rated current to 12%, and the steady state error of 18% meets the specifications. In rectified load test, the root mean square value of circulating current is reduced from 11% of the rated current to 7%, and THDv=2.8% meets the 3% specification. Therefore, under the restriction of the voltage regulation specification, the designed virtual resistance loop on the basis of the designed voltage regulation control and droop control can make the circulating current meet the design requirements in both steady state and transient state.

中文摘要 ............................................................................................................................i
英文摘要 ......................................................................................................................... iii
誌謝 ................................................................................................................................... v
目錄 ..................................................................................................................................vi
表列 ............................................................................................................................... viii
圖列 ..................................................................................................................................ix
第一章 緒論 ..................................................................................................................... 1
1.1 研究背景與發展近況 ..................................................................................... 1
1.2 研究動機與目的 ............................................................................................. 5
1.3 研究方法與系統架構 ..................................................................................... 6
1.4 論文架構大綱 ................................................................................................. 7
第二章 逆變器並聯操作的分流控制策略 .................................................................... 9
2.1 微電網應用之逆變器控制架構簡介 ............................................................. 9
2.2 微電網之階層化控制架構 ........................................................................... 10
2.3 以垂降控制為基礎之分流控制策略 ........................................................... 13
2.3.1 傳統之????−????、????−????垂降控制 ..................................................... 13
2.3.2 ????−????、????−????垂降控制 ................................................................. 15
2.3.3 垂降控制 結合 虛擬阻抗 之 分流 控制策略 ..................................... 18
第三章 電流控制器設計 ............................................................................................... 21
3.1 電流控制器系統架構與操作條件 ............................................................... 21
3.2 數位控制之模型方塊圖與時間延遲分析 ................................................... 23
3.3 比例電流控制器 ........................................................................................... 27
3.4 預測型電流控制器設計與時間延遲補償 ................................................... 29
3.5 飽和電感之L-I曲線量測與電感值補償 ...................................................... 34
3.6 操作條件變化下的控制器參數優化與增益規劃 ....................................... 43
第四章 逆變器之穩壓控制器設計 ............................................................................... 56
4.1 逆變器之穩壓控制系統架構 ....................................................................... 56
4.2 雙迴路穩壓控制器之小信號模型 ............................................................... 59
vii
4.3 電壓迴路補償器設計 ................................................................................... 63
4.3.1 ????????????????規格對應的輸出阻抗規格與目標頻寬估算 ....................... 63
4.3.2 相位領先補償器設計相位領先補償器設計 ..................................................................... 68
4.3.3 比例諧比例諧振振加加相位領先相位領先之之補償器設計補償器設計 ............................................. 72
4.3.4 雙迴路穩壓控制雙迴路穩壓控制器的器的模擬結果模擬結果 ..................................................... 78
第五章 逆變器並聯操作之分流控制器設計 ............................................................... 84
5.1 逆變器並聯操作之分流控制架構 ............................................................... 84
5.2 虛擬電阻迴路分析與設計 ........................................................................... 89
5.2.1 不同虛擬電阻的實功分配與穩態誤差分析不同虛擬電阻的實功分配與穩態誤差分析 ................................. 89
5.2.2 不同虛擬電阻的整流性負載測試電壓????????????????與循環電流分析 ... 94
5.2.3 ????????????????、穩態誤差限制下的虛擬電阻設計 ................................... 96
5.2.4 虛擬電阻迴路頻寬分析 ................................................................. 96
5.3 並聯操作之模擬結果 ................................................................................. 103
5.3.1 傳輸線等長的並聯控制穩態響應傳輸線等長的並聯控制穩態響應 ............................................... 103
5.3.2 傳輸線不等長的並聯控制穩態響應傳輸線不等長的並聯控制穩態響應 ........................................... 105
5.3.3 並聯切換之暫態響應並聯切換之暫態響應 ................................................................... 108
第六章 多台逆變器並聯操作實驗結果 ..................................................................... 113
6.1 多台逆變器並聯系統架構與實驗平台設定 ............................................. 113
6.2 多台逆變器並聯操作實驗結果 ................................................................. 116
6.2.1 單台逆變器穩壓控制單台逆變器穩壓控制加入加入PR補償前後之比較補償前後之比較 .......................... 116
6.2.2 傳輸線等長的多台逆變器分流控制 ........................................... 121
6.2.3 傳輸線不等長的多台逆變器分流控制 ....................................... 123
6.2.4 不等比例功率分配的多台逆變器分流控制 ............................... 126
第七章 結論與未來發展 ............................................................................................. 128
7.1 結論 .................................................................................................................. 128
7.2 未來發展 .......................................................................................................... 128
參考文獻 ....................................................................................................................... 130
作者簡介 ....................................................................................................................... 133
A. 個人資料 ........................................................................................................... 133
B. 學歷 ................................................................................................................... 133

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