【正文】 博士學位論文電能質(zhì)量參數(shù)檢測算法的研究Research on estimating algorithms of power quality indicesbyJIANG Yaqun. (Hunan University) 1994. (Hunan University) 2000A dissertation submitted in partial satisfaction of theRequirements for the degree ofDoctor of EngineeringinElectrical Engineeringin theGraduate SchoolofHunan UniversitySupervisorProfessor HE YigangMay, 2009LXXIII湖 南 大 學學位論文原創(chuàng)性聲明本人鄭重聲明：所呈交的論文是本人在導師的指導下獨立進行研究所取得的研究成果。除了文中特別加以標注引用的內(nèi)容外，本論文不包含任何其他個人或集體已經(jīng)發(fā)表或撰寫的成果作品。對本文的研究做出重要貢獻的個人和集體，均已在文中以明確方式標明。本人完全意識到本聲明的法律后果由本人承擔。作者簽名： 日期： 年 月 日學位論文版權(quán)使用授權(quán)書本學位論文作者完全了解學校有關(guān)保留、使用學位論文的規(guī)定，同意學校保留并向國家有關(guān)部門或機構(gòu)送交論文的復印件和電子版，允許論文被查閱和借閱。本人授權(quán)湖南大學可以將本學位論文的全部或部分內(nèi)容編入有關(guān)數(shù)據(jù)庫進行檢索，可以采用影印、縮印或掃描等復制手段保存和匯編本學位論文。本學位論文屬于保密□，在______年解密后適用本授權(quán)書。√不保密□。（請在以上相應(yīng)方框內(nèi)打“√”）作者簽名： 日期： 年 月 日導師簽名： 日期： 年 月 日IX博士學位論文摘 要隨著國民經(jīng)濟和現(xiàn)代科學技術(shù)的飛速發(fā)展，電能質(zhì)量問題正受到越來越多的關(guān)注。全面有效的檢測和分析是改善和提高電能質(zhì)量的前提和依據(jù)，快速、先進、有效的參數(shù)估計算法是實現(xiàn)有效檢測和分析的基礎(chǔ)。由于電力信號的復雜性和電能質(zhì)量內(nèi)涵的擴展性，以及不斷提高的測量精度、廣度與測量速度的要求，電能質(zhì)量指標參數(shù)測量技術(shù)有待進一步發(fā)展和提高。本文依據(jù)國內(nèi)外相關(guān)電能質(zhì)量標準，結(jié)合電能質(zhì)量研究現(xiàn)狀和工程實際需要，應(yīng)用數(shù)字信號處理技術(shù)及電力系統(tǒng)自動化技術(shù)，研究電能質(zhì)量中最重要和最受關(guān)注的指標參數(shù)的測量理論和估計算法。主要工作包括：1）提出了一種基于自適應(yīng)短時傅里葉變換的基波參數(shù)估計算法，并以此算法為基礎(chǔ)計算電壓偏差、頻率偏差、三相不平衡度和功率因數(shù)等基本電能質(zhì)量參數(shù)。算法采用固定的采樣周期，采樣頻率不需隨信號頻率的變化而調(diào)整，實現(xiàn)簡單；算法不需要迭代運算，可一次得到參數(shù)估計值，計算量小，響應(yīng)時間快；通過采用矩形自卷積窗，并自適應(yīng)地確定與信號頻率相適應(yīng)的時間窗寬度，有效抑制了頻譜泄漏對基波參數(shù)測量的影響，測量精度高。2）根據(jù)諧波和間諧波各自的頻譜特征，提出了一種新的諧波、間諧波實時檢測算法。算法根據(jù)正余弦函數(shù)的特性，將各次諧波分量變換成直流分量，經(jīng)由低通濾波后估計其有效值和初相角；從原信號中去除基波和諧波分量，再通過搜尋頻譜極大值獲取間諧波頻率及有效值和初相角。算法實現(xiàn)簡單，精度高，動態(tài)跟蹤特性好，適合于離散頻譜電壓、電流信號的諧波、間諧波參數(shù)實時估計。3）諧波、間諧波和閃變關(guān)系密切，但現(xiàn)有諧波、間諧波的檢測與閃變的檢測實現(xiàn)方法不同且無關(guān)聯(lián)。本文推導了間諧波和調(diào)幅波對于閃變的等價關(guān)系，在此基礎(chǔ)上，將間諧波檢測和閃變檢測結(jié)合起來，根據(jù)國家標準和IEC標準的閃變檢測技術(shù)規(guī)范，提出了一種基于間諧波估計的閃變參數(shù)檢測新算法。新算法除了能求取瞬時視感度、短時間閃變值和長時間閃變值等反映閃變強弱的參數(shù)外，還能提供電壓波動頻度和幅度的信息，有利于電壓波動與閃變的分析和治理，為閃變檢測提供了一種新的實現(xiàn)模式。4）應(yīng)用數(shù)字圖像處理理論，采用圖像邊緣形態(tài)檢測算子，實現(xiàn)了暫態(tài)電能質(zhì)量擾動的檢測和時間定位。該方法具有實現(xiàn)簡單，計算量小，對采樣頻率要求低，實時性好等特點，可對電壓暫降、暫升、短時中斷、短時高頻振蕩、陷波等常見暫態(tài)電力擾動進行有效檢測。5）減小背景梯度是實現(xiàn)暫態(tài)電能質(zhì)量擾動檢測的關(guān)鍵。針對非擾動情況下電力信號周期交替變化引起的背景梯度，提出了基于TopHat形態(tài)變換的抑制方法，針對噪聲引起的背景梯度，構(gòu)造了合適的形態(tài)濾波器，提高了擾動檢測的靈敏度。6）提出了基于順序形態(tài)學和TopHat形態(tài)變換的擾動檢測方法，既可有效抑制信號平穩(wěn)變化引起的背景梯度，又具有較好的抗噪聲能力，同時很好地保留了擾動信號突變的局部細節(jié)，保證了擾動檢測靈敏度和時間定位精度。7）提出了一種改進的單相電壓暫降特征參數(shù)實時檢測算法。通過構(gòu)造新的變換矩陣，減小了傳統(tǒng)方法構(gòu)造虛擬三相系統(tǒng)的延時，可對單相電壓暫降幅值、持續(xù)時間和相位跳變等特征參數(shù)進行近乎瞬時的估計。分析了單相電壓暫降檢測時“異動”現(xiàn)象的產(chǎn)生原因，提出了基于形態(tài)運算的解決方法。8）提出了一種改進的三相電壓暫降檢測算法。針對三相不平衡電壓暫降，通過正序dq變換和負序dq變換，經(jīng)由形態(tài)低通濾波得到三相電壓的基波正序、負序分量，采用改進的單相電壓暫降檢測算法得到零序分量，進而得到各相電壓暫降的特征參數(shù)。改進方法實時性好，參數(shù)估計精確，滿足電壓暫降實時檢測的要求，可應(yīng)用于電壓暫降監(jiān)測、評估及動態(tài)電壓恢復器（DVR）對電壓暫降的實時補償控制。本文提出的電能質(zhì)量參數(shù)估計理論和系列算法，為電能質(zhì)量實時檢測和離線分析提供了有效的工具。仿真研究驗證了所提算法的可行性和有效性；算法已成功應(yīng)用于“基于虛擬儀器技術(shù)的電能質(zhì)量綜合測試儀”的研制和開發(fā)中。關(guān)鍵詞：電能質(zhì)量；參數(shù)估計；數(shù)字信號處理；檢測；算法AbstractWith rapid development of economy and science technology, power quality (PQ) problems have increasingly bee a substantial concern in recent years. Completely and accurately assessing power quality is the first step in solving and mitigating the problems, fast and advanced algorithms are the basis for effective measurement and evaluation.Due to the plexity of power system signal and the variety of power quality event, it is a challenge to detect power quality indices pletely, accurately and promptly.In accordance with national and international power quality standard, a systematic and indepth research about power quality major indices evaluation is carried out based on analyzing domestic and overseas research situations. By use of digital signalprocessing methods as well as power system automation techniques, the research works pay more attention to the measurement theories and estimation algorithms of important indices. The main contributions of this dissertation are listed as follows:1）A new digital algorithm based on adaptive ShortTime Fourier Transform (STFT) is presented to estimate some basic power quality indices, such as voltage deviation, frequency deviation, voltage unbalance degree and power factor of fundamental ponent. The algorithm employs fixed sampling period although the frequency of the signal varies. No recursive calculation is needed to get evaluation values of above mentioned parameters. As a result, the algorithm is easy to implement with less putation burden and short response time. To restrain the spectrum leakage of harmonics, a novel kind of window called Rectangle SelfConvolution Window (RSCW) is adopted and the window length is adjusted according to the frequency variation of the signal. It is thus suitable for realtime measuring with high presicion.2）According to the spectrum characteristics of harmonics/interharmonics, an approach is proposed to pute harmonics/interharmonics in real time. Considering the characteristic of sine/cosine function, the harmonic ponent can be transformed into DC ponent, the rms value and initial phase angle of harmonic then can be got after lowpass filtering. As to interharmonics, it is generally considered to be a challenge because the interharmonics only have small ratio, it is hard to estimate them accurately. By subtracting fundamental and harmonic ponents from the original signal, maximum spectrum searching technique is used to pute frequency, rms value and initial phase angle of interharmonic. The proposed approach is easy to implement with high precision and good dynamic tracking feature, it suits to estimate harmonic/interharmonic parameters of voltage or current signals with discrete spectrum.3）It is known that flicker phenomena are closely related with harmonics and interharmonics, but at present, the detection methods of harmonics/interharmonics and flicker are pletely different. Based on deducing the equivalent relation of interharmonic and amplitude modulation wave to flicker, the detection methods of interharmonic and flicker are bined. Therefore, according to national and International Electrotechnical Commission (IEC) standard, a new flicker evaluation algorithm is presented based on interharmonic estimation. The algorithm can not only pute instantaneous visual acuity, shortterm flicker severity index and longterm flicker severity index, but also pr