【摘要】：近年來,隨著人們對電能質(zhì)量和電網(wǎng)安全的需求越來越高,智能電網(wǎng)的發(fā)展速度越來越快。智能變電站作為電能傳輸過程中的中轉(zhuǎn)樞紐,發(fā)揮的重要的作用,而智能變電站中的主要設(shè)備電力變壓器能否可靠運(yùn)行關(guān)系著整個(gè)電網(wǎng)的安全。所以對電力變壓器的狀態(tài)進(jìn)行監(jiān)測顯得尤為重要。變壓器的運(yùn)行狀態(tài)與變壓器的噪聲密切相關(guān)。本文主要設(shè)計(jì)了一套噪聲測量分析系統(tǒng),對變壓器的噪聲進(jìn)行采集,計(jì)算其聲壓級,觀察分析變壓器的噪聲特性以達(dá)到實(shí)時(shí)監(jiān)測變壓器運(yùn)行狀態(tài)的目的。論文主要從噪聲測量計(jì)算平臺(tái)的設(shè)計(jì)、噪聲信號的聲級計(jì)算、噪聲信號的分析三個(gè)方面對該系統(tǒng)進(jìn)行設(shè)計(jì)。首先,對噪聲測量分析平臺(tái)進(jìn)行整體設(shè)計(jì),包括硬件的選型和軟件任務(wù)流程的設(shè)計(jì),其中硬件設(shè)計(jì)包括噪聲數(shù)據(jù)采集模塊、運(yùn)算處理與控制模塊、儲(chǔ)存模塊、通訊模塊,軟件架構(gòu)主要包括FPGA控制數(shù)據(jù)采集流程,CPU計(jì)算任務(wù)的運(yùn)行流程的設(shè)計(jì)。其次,基于IIR數(shù)字濾波器設(shè)計(jì)了A、C、Z頻率計(jì)權(quán)網(wǎng)絡(luò),并通過MATLAB仿真得出其誤差符合1級允差標(biāo)準(zhǔn),適用于電力變壓器噪聲聲壓級的高精度計(jì)算。將實(shí)數(shù)快速傅里葉變換算法應(yīng)用于噪聲的頻譜計(jì)算,相對于普通快速傅里葉算法,其計(jì)算量更少。通過觀察變壓器噪聲信號的聲壓級與頻譜值,可以實(shí)時(shí)監(jiān)測變壓器的運(yùn)行狀態(tài)。然后,在后臺(tái)對噪聲信號進(jìn)行進(jìn)一步的頻譜分析,提出了用改進(jìn)的1/3倍頻程方法表示FFT,即用一段頻帶內(nèi)的最大譜值表示該頻帶的譜值,用MATLAB仿真驗(yàn)證了其可行性。針對FFT的頻譜泄漏現(xiàn)象,通過加窗函數(shù)減少誤差,之后通過補(bǔ)償添加窗函數(shù)引起的衰減值,提高了FFT分析的精度。針對FFT在頻譜分析中的缺陷,提出了小波變換用于噪聲信號的頻譜分析,仿真分析了小波分析用于噪聲信號頻率成分的檢測、噪聲信號奇異性的檢測。小波分析不僅能夠進(jìn)行頻域成分的分析,還能分析信號的時(shí)域特性,為電力變壓器噪聲信號的故障分析提供了一種有效的分析手段。最后,利用本文設(shè)計(jì)的噪聲測量分析平臺(tái)采集得到現(xiàn)場的噪聲信號,根據(jù)本文介紹的算法對實(shí)際信號進(jìn)行計(jì)算分析,驗(yàn)證算法的實(shí)用性。證明本系統(tǒng)完全適用于變壓器噪聲特性的計(jì)算與分析。
[Abstract]:In recent years, with the increasing demand for power quality and power grid security, the development of smart grid is getting faster and faster. As a transit hub in the process of power transmission, intelligent substation plays an important role, and the reliable operation of the main equipment power transformer in intelligent substation is related to the security of the whole power grid. Therefore, it is particularly important to monitor the state of power transformer. The operation state of transformer is closely related to the noise of transformer. In this paper, a set of noise measurement and analysis system is designed to collect the noise of the transformer, calculate its sound pressure level, observe and analyze the noise characteristics of the transformer in order to monitor the running state of the transformer in real time. This paper mainly designs the system from three aspects: the design of noise measurement and calculation platform, the sound level calculation of noise signal and the analysis of noise signal. Firstly, the overall design of noise measurement and analysis platform is carried out, including the selection of hardware and the design of software task flow. The hardware design includes noise data acquisition module, operation processing and control module, storage module and communication module. The software architecture mainly includes FPGA control data acquisition flow and CPU computing task operation flow design. Secondly, the A, C, Z frequency weight network is designed based on IIR digital filter, and the error accords with the level 1 tolerance standard by MATLAB simulation, which is suitable for the high precision calculation of noise sound pressure level of power transformer. The real fast Fourier transform algorithm is applied to the spectrum calculation of noise, which is less than the ordinary fast Fourier algorithm. By observing the sound voltage level and spectrum value of transformer noise signal, the running state of transformer can be monitored in real time. Then, the further spectrum analysis of the noise signal is carried out in the background, and an improved 1 鈮，

本文編號：2487222