本文選題：SOM神經(jīng)網(wǎng)絡(luò)　切入點：并網(wǎng)逆變器　出處：《安徽理工大學(xué)》2016年碩士論文　論文類型：學(xué)位論文

【摘要】：隨著快速發(fā)展的生產(chǎn)社會,致使能源需求不斷增長,在全球范圍內(nèi)的能源短缺的危機(jī)變得日益嚴(yán)峻�；茉丛诘厍蛑惺且环N非再生資源,終究會致使其耗盡�；Y源也會隨著資源數(shù)量的不斷減少,出現(xiàn)價格會相應(yīng)的提高,嚴(yán)重制約著人民生活水平和社會的生產(chǎn)發(fā)展的提高�？稍偕茉丛谌蚍秶鷥�(nèi)的能源需求有著相當(dāng)重要的作用,在我們國家這樣的人口大國就更加顯得尤為重要。太陽能能源在我們國家非常富足,具有相當(dāng)好的發(fā)展前景。將太陽能光伏陣列發(fā)出的直流電通過光伏逆變器變換成能夠滿足市電使用條件的交流電然后直接并入公共電網(wǎng)稱之為光伏并網(wǎng)發(fā)電系統(tǒng)。當(dāng)陽光充足時則不需使用市網(wǎng)電,可選擇采用太陽能發(fā)出的電；當(dāng)太陽能發(fā)電達(dá)不到使用量標(biāo)準(zhǔn)或陽光不充裕時,其系統(tǒng)可通過其控制部分切換到市網(wǎng)電給予供電。這種系統(tǒng)的最重要部分是光伏并網(wǎng)逆變器,其中光伏并網(wǎng)逆變器的可靠運(yùn)行決定著其系統(tǒng)運(yùn)行的安全性。由若干開關(guān)器件及電感、電容組合而成的并網(wǎng)逆變器主電路,在逆變電路運(yùn)行過程的故障可劃分成硬故障(結(jié)構(gòu)性故障)和軟故障(參數(shù)性故障),其中軟故障對電路的可靠性具有很大的影響,其中較為突出的是濾波電容的軟故障。由電容的引出電極長時間經(jīng)受大電流的充、放電沖擊造成電容出現(xiàn)不同程度的氧化現(xiàn)象,電容儲電能力也會隨著減小,也就是相當(dāng)于電容容量大幅衰減。由于電容容量的變小,通常體現(xiàn)為帶負(fù)載能力減弱,當(dāng)負(fù)載增加時則會發(fā)生直流回路欠壓的故障。從而導(dǎo)致更大程度上損壞電容,也有能夠?qū)е轮绷骰芈樊a(chǎn)生電壓振蕩,嚴(yán)重?fù)p毀逆變模塊。本文主要分析逆變器中的電解電容在不同容差下的軟故障特征,根據(jù)光伏并網(wǎng)逆變器特點,提出了一種光伏并網(wǎng)逆變器主電路拓?fù)浣Y(jié)構(gòu)中電解電容軟故障診斷方法,并利用MATLAB搭建了光伏并網(wǎng)逆變器的仿真模型。因為逆變器的電解電容隨著運(yùn)行時間的推移出現(xiàn)不同程度的老化現(xiàn)象,致使電容值減小,導(dǎo)致電網(wǎng)中輸出的線電壓偏離正常工作時的電壓,故本文采用逆變器三相輸出電壓信號作為特征量,并采用小波變換的方法對其進(jìn)行處理。再利用BP神經(jīng)網(wǎng)絡(luò)和SOM神經(jīng)網(wǎng)絡(luò)分別對逆變器進(jìn)行軟故障診斷,通過仿真實驗得出診斷結(jié)果,并將這兩種診斷方法進(jìn)行比較,得到SOM神經(jīng)網(wǎng)絡(luò)在逆變器軟故障診斷方面更具有一定優(yōu)勢。
[Abstract]:With the rapid development of productive society, energy demand is increasing, and the global crisis of energy shortage is becoming more and more serious. Fossil energy is a kind of non-renewable resource in the earth. It will eventually be depleted. The fossil resources will also increase as the amount of resources continues to decrease, and the prices will rise accordingly. It seriously restricts the improvement of people's living standards and the productive development of society. Renewable energy sources play a very important role in the global energy demand, This is all the more important in a populous country like ours. Solar energy is very rich in our country. The direct current generated by the solar photovoltaic array is converted by the photovoltaic inverter into alternating current which can meet the requirements of the municipal electricity supply and is directly incorporated into the public grid as the photovoltaic grid-connected power generation system. When there is plenty of sunshine, there is no need for market electricity, The option is to use electricity from solar energy; when solar power does not meet usage standards or when there is not enough sunlight, its system can be switched to market electricity through its control portion. The most important part of such a system is a photovoltaic grid-connected inverter. The reliable operation of photovoltaic grid-connected inverter determines the safety of the system. The main circuit of grid-connected inverter is composed of several switching devices, inductors and capacitors. During the operation of the inverter circuit, the faults can be divided into hard faults (structural faults) and soft faults (parametric faults), in which soft faults have a great impact on the reliability of the circuit. Among them, the soft fault of the filter capacitor is prominent. The discharge shock causes the capacitance to be oxidized in different degree, and the capacitance storage capacity will decrease with the discharge shock. Because the capacitance capacity becomes smaller, the capacity of the capacitor is usually reflected in the weakening of the capacity of the load. When the load increases, the failure of the DC circuit will occur. This will result in more damage to the capacitance. It can also cause voltage oscillation in DC circuit and seriously damage inverter module. This paper mainly analyzes the characteristics of soft fault of electrolytic capacitance in inverter under different tolerances, according to the characteristics of photovoltaic grid-connected inverter, A soft fault diagnosis method for electrolytic capacitance in the topology of the main circuit of photovoltaic grid-connected inverter is presented. The simulation model of grid-connected photovoltaic inverter is built by using MATLAB. Because the electrolytic capacitance of the inverter is aging in varying degrees with the running time, the capacitance value decreases. The output line voltage in the power network deviates from the normal working voltage. Therefore, the inverter three-phase output voltage signal is used as the characteristic value in this paper. The soft fault diagnosis of inverter is carried out by using BP neural network and SOM neural network, and the results are obtained by simulation experiment, and the two diagnosis methods are compared. SOM neural network has some advantages in soft fault diagnosis of inverter.
【學(xué)位授予單位】：安徽理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：TM464

【參考文獻(xiàn)】

相關(guān)期刊論文 前9條

1 陳丹江;葉銀忠;華容;;基于波形實時分析的動車組三電平逆變器故障診斷技術(shù)[J];電工技術(shù)學(xué)報;2014年06期

2 陳丹江;葉銀忠;;基于多神經(jīng)網(wǎng)絡(luò)的三電平逆變器器件開路故障診斷方法[J];電工技術(shù)學(xué)報;2013年06期

3 何湘寧;吳巖松;楊兵建;汪捚;鄧焰;;大功率三電平逆變器的開關(guān)模態(tài)轉(zhuǎn)換狀態(tài)的實時監(jiān)測[J];中國電機(jī)工程學(xué)報;2012年30期

4 張志;謝運(yùn)祥;樂江源;陳林;;二極管鉗位型單相三電平逆變器空間矢量脈寬調(diào)制方法[J];中國電機(jī)工程學(xué)報;2010年27期

5 湯清泉;顏世超;盧松升;劉正之;;三電平逆變器的功率管開路故障診斷[J];中國電機(jī)工程學(xué)報;2008年21期

6 林磊,鄒云屏,鐘和清,鄒旭東,丁凱;二極管箝位型三電平逆變器控制系統(tǒng)研究[J];中國電機(jī)工程學(xué)報;2005年15期

7 蘇鵬聲,王志強(qiáng),姜建國;用人工神經(jīng)網(wǎng)絡(luò)診斷電力電子電路主回路故障[J];清華大學(xué)學(xué)報(自然科學(xué)版);1999年03期

8 徐德洪，程肇基，崔學(xué)軍;用傅里葉分析法診斷電力電子電路的故障[J];浙江大學(xué)學(xué)報(自然科學(xué)版);1994年06期

9 徐德洪,程肇基,范云其;;診斷電力電子電路故障的新方法──沃爾什分析法[J];電工技術(shù)學(xué)報;1993年01期

相關(guān)碩士學(xué)位論文 前10條

1 甘露;極限學(xué)習(xí)機(jī)的研究與應(yīng)用[D];西安電子科技大學(xué);2014年

2 周江Z，

本文編號：1606512