【正文】 博士學(xué)位論文電能質(zhì)量參數(shù)檢測(cè)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(xué)學(xué)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(dǎo)師的指導(dǎo)下獨(dú)立進(jìn)行研究所取得的研究成果。除了文中特別加以標(biāo)注引用的內(nèi)容外，本論文不包含任何其他個(gè)人或集體已經(jīng)發(fā)表或撰寫(xiě)的成果作品。對(duì)本文的研究做出重要貢獻(xiàn)的個(gè)人和集體，均已在文中以明確方式標(biāo)明。本人完全意識(shí)到本聲明的法律后果由本人承擔(dān)。作者簽名： 日期： 年 月 日學(xué)位論文版權(quán)使用授權(quán)書(shū)本學(xué)位論文作者完全了解學(xué)校有關(guān)保留、使用學(xué)位論文的規(guī)定，同意學(xué)校保留并向國(guó)家有關(guān)部門(mén)或機(jī)構(gòu)送交論文的復(fù)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(xué)可以將本學(xué)位論文的全部或部分內(nèi)容編入有關(guān)數(shù)據(jù)庫(kù)進(jìn)行檢索，可以采用影印、縮印或掃描等復(fù)制手段保存和匯編本學(xué)位論文。本學(xué)位論文屬于保密□，在______年解密后適用本授權(quán)書(shū)?！滩槐Ｃ堋酢＃ㄕ?qǐng)?jiān)谝陨舷鄳?yīng)方框內(nèi)打“√”）作者簽名： 日期： 年 月 日導(dǎo)師簽名： 日期： 年 月 日IX博士學(xué)位論文摘 要隨著國(guó)民經(jīng)濟(jì)和現(xiàn)代科學(xué)技術(shù)的飛速發(fā)展，電能質(zhì)量問(wèn)題正受到越來(lái)越多的關(guān)注。全面有效的檢測(cè)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(jìn)、有效的參數(shù)估計(jì)算法是實(shí)現(xiàn)有效檢測(cè)和分析的基礎(chǔ)。由于電力信號(hào)的復(fù)雜性和電能質(zhì)量?jī)?nèi)涵的擴(kuò)展性，以及不斷提高的測(cè)量精度、廣度與測(cè)量速度的要求，電能質(zhì)量指標(biāo)參數(shù)測(cè)量技術(shù)有待進(jìn)一步發(fā)展和提高。本文依據(jù)國(guó)內(nèi)外相關(guān)電能質(zhì)量標(biāo)準(zhǔn)，結(jié)合電能質(zhì)量研究現(xiàn)狀和工程實(shí)際需要，應(yīng)用數(shù)字信號(hào)處理技術(shù)及電力系統(tǒng)自動(dòng)化技術(shù)，研究電能質(zhì)量中最重要和最受關(guān)注的指標(biāo)參數(shù)的測(cè)量理論和估計(jì)算法。主要工作包括：1）提出了一種基于自適應(yīng)短時(shí)傅里葉變換的基波參數(shù)估計(jì)算法，并以此算法為基礎(chǔ)計(jì)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(hào)頻率的變化而調(diào)整，實(shí)現(xiàn)簡(jiǎn)單；算法不需要迭代運(yùn)算，可一次得到參數(shù)估計(jì)值，計(jì)算量小，響應(yīng)時(shí)間快；通過(guò)采用矩形自卷積窗，并自適應(yīng)地確定與信號(hào)頻率相適應(yīng)的時(shí)間窗寬度，有效抑制了頻譜泄漏對(duì)基波參數(shù)測(cè)量的影響，測(cè)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(shí)時(shí)檢測(cè)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(jì)其有效值和初相角；從原信號(hào)中去除基波和諧波分量，再通過(guò)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(shí)現(xiàn)簡(jiǎn)單，精度高，動(dòng)態(tài)跟蹤特性好，適合于離散頻譜電壓、電流信號(hào)的諧波、間諧波參數(shù)實(shí)時(shí)估計(jì)。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(cè)與閃變的檢測(cè)實(shí)現(xiàn)方法不同且無(wú)關(guān)聯(lián)。本文推導(dǎo)了間諧波和調(diào)幅波對(duì)于閃變的等價(jià)關(guān)系，在此基礎(chǔ)上，將間諧波檢測(cè)和閃變檢測(cè)結(jié)合起來(lái)，根據(jù)國(guó)家標(biāo)準(zhǔn)和IEC標(biāo)準(zhǔn)的閃變檢測(cè)技術(shù)規(guī)范，提出了一種基于間諧波估計(jì)的閃變參數(shù)檢測(cè)新算法。新算法除了能求取瞬時(shí)視感度、短時(shí)間閃變值和長(zhǎng)時(shí)間閃變值等反映閃變強(qiáng)弱的參數(shù)外，還能提供電壓波動(dòng)頻度和幅度的信息，有利于電壓波動(dòng)與閃變的分析和治理，為閃變檢測(cè)提供了一種新的實(shí)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(cè)算子，實(shí)現(xiàn)了暫態(tài)電能質(zhì)量擾動(dòng)的檢測(cè)和時(shí)間定位。該方法具有實(shí)現(xiàn)簡(jiǎn)單，計(jì)算量小，對(duì)采樣頻率要求低，實(shí)時(shí)性好等特點(diǎn)，可對(duì)電壓暫降、暫升、短時(shí)中斷、短時(shí)高頻振蕩、陷波等常見(jiàn)暫態(tài)電力擾動(dòng)進(jìn)行有效檢測(cè)。5）減小背景梯度是實(shí)現(xiàn)暫態(tài)電能質(zhì)量擾動(dòng)檢測(cè)的關(guān)鍵。針對(duì)非擾動(dòng)情況下電力信號(hào)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(duì)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(dòng)檢測(cè)的靈敏度。6）提出了基于順序形態(tài)學(xué)和TopHat形態(tài)變換的擾動(dòng)檢測(cè)方法，既可有效抑制信號(hào)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(shí)很好地保留了擾動(dòng)信號(hào)突變的局部細(xì)節(jié)，保證了擾動(dòng)檢測(cè)靈敏度和時(shí)間定位精度。7）提出了一種改進(jìn)的單相電壓暫降特征參數(shù)實(shí)時(shí)檢測(cè)算法。通過(guò)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(shí)，可對(duì)單相電壓暫降幅值、持續(xù)時(shí)間和相位跳變等特征參數(shù)進(jìn)行近乎瞬時(shí)的估計(jì)。分析了單相電壓暫降檢測(cè)時(shí)“異動(dòng)”現(xiàn)象的產(chǎn)生原因，提出了基于形態(tài)運(yùn)算的解決方法。8）提出了一種改進(jìn)的三相電壓暫降檢測(cè)算法。針對(duì)三相不平衡電壓暫降，通過(guò)正序dq變換和負(fù)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(fù)序分量，采用改進(jìn)的單相電壓暫降檢測(cè)算法得到零序分量，進(jìn)而得到各相電壓暫降的特征參數(shù)。改進(jìn)方法實(shí)時(shí)性好，參數(shù)估計(jì)精確，滿足電壓暫降實(shí)時(shí)檢測(cè)的要求，可應(yīng)用于電壓暫降監(jiān)測(cè)、評(píng)估及動(dòng)態(tài)電壓恢復(fù)器（DVR）對(duì)電壓暫降的實(shí)時(shí)補(bǔ)償控制。本文提出的電能質(zhì)量參數(shù)估計(jì)理論和系列算法，為電能質(zhì)量實(shí)時(shí)檢測(cè)和離線分析提供了有效的工具。仿真研究驗(yàn)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(cè)試儀”的研制和開(kāi)發(fā)中。關(guān)鍵詞：電能質(zhì)量；參數(shù)估計(jì)；數(shù)字信號(hào)處理；檢測(cè)；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