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臺灣能源期刊論文全文

臺灣能源期刊第5卷第2期內容

出刊日期:June, 2018

題目
雙饋感應發電機之諧波電流與不平衡電流整合控制系統研製
Title
Implement of the Integrated Harmonic Current and Unbalanced Currents Control System for DFIG
作者
陳宗柏
Authors
Tsung-Po Chen
摘要
雙饋感應發電機運轉於低轉差範圍時,轉子側變頻器提供了電壓餘裕度以做為諧波控制以及不平衡控制之用。本論文針對並聯了單相、三相非線性負載,以及雙饋感應發電機,與三相不平衡電網併網之供電分路,作諧波與不平衡現象之探討,與分析,並建立一個PC-based控制系統,以MathworksTM公司之xpc target軟體配合PC主機以及相關的控制卡,來實現風力發電控制系統,其程式發展以圖形化、階層化方式達成,除縮短開發時程之外,PC-based控制系統也提供網路監控以及開放平台之便利。所提出之控制系統主要功能為對流經併網分路電流控制回授點之諧波電流與不平衡電流,藉由受控制的雙饋感應發電機定子輸出電流加以補償消除。本論文在PC-based控制系統合成正、負向序與5、7次諧波之轉子側換流器電壓向量,來控制雙饋感應發電機轉子電流,進而達成雙饋感應發電機定子側實功、虛功、三相不平衡電流以及5次、7次諧波電流控制。本論文對實驗系統作數學分析,並以PC-based快速原型系統,由所提出之實驗結果,可以驗證系統之可行性與效能。
關鍵字
雙饋感應發電機,換流器,諧波失真,風力發電,三相不平衡
Abatract
When the DFIG rotates under low slip region, the fundamental voltage of the rotor side converter will work under a low voltage situation. Besides the fundamental voltage vector, different frequencies voltage vectors can be added to control the three-phase unbalance current and the selected harmonics currents of the rotor. This paper presents a study on the branch that includes single-phase and three-phase non-linear load and in parallel with a DFIG. A PC-based real-time control system was developed for DFIG control, the software is based on the Simulink xpc target environment. The hardware system is a PC system, including main board and many control cards. The network communication and monitoring abilities are essentially included and the programs of the proposed control systems are graphical and hierarchical style. Four voltage vectors sequences with different rotating speed and direction are composited to a voltage vector sequence to generate three-phase SVPWM voltages for DFIG rotor current control. By means of rotor current control, the DFIG stator can generate designated complex power. Furthermore, the DFIG can generates three-phase unbalanced current and harmonics currents, i.e. the 5th and 7th harmonics, to compensate the unbalanced current and harmonics currents of the controlled branch. The mathematical analysis and rapid model experimental results are provided for validate the performance of the proposed DFIG control system.
Keywords
DFIG, converter, harmonic distortion, wind-power generation, unbalance