發(fā)布時間：2018-03-18 18:07

  本文選題：隔離型并網(wǎng)逆變器　切入點：非隔離型并網(wǎng)逆變器　出處：《華北電力大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：光伏發(fā)電迅速發(fā)展,光伏并網(wǎng)逆變器作為光伏系統(tǒng)主要設(shè)備,應(yīng)給予極大的重視。由于各種原因,逆變器輸出的交流電中會含有直流分量,,這些直流分量不僅對設(shè)備本身有危害,還會嚴重影響電網(wǎng)的電能質(zhì)量,所以一定要對其加以抑制和補償。本文首先對現(xiàn)在光伏系統(tǒng)廣泛應(yīng)用的幾種光伏逆變器拓撲結(jié)構(gòu)做了比較分析。研究發(fā)現(xiàn),隔離型光伏并網(wǎng)逆變器輸出的交流中基本不含直流分量；但是非隔離型并網(wǎng)逆變器由于缺少了隔離變壓器的隔離作用,逆變器就會向電網(wǎng)中傳送直流分量。第二,總結(jié)國內(nèi)外對光伏并網(wǎng)逆變器輸出直流分量的技術(shù)要求,分析非隔離型并網(wǎng)逆變器直流分量的產(chǎn)生機理以及直流分量對電網(wǎng)設(shè)備的危害。并從其產(chǎn)生原因入手,分析軟件直流分量抑制方法和硬件直流分量抑制方法。第三,比較分析了現(xiàn)有的抑制直流分量的抑制方法。主要是從逆變器拓撲結(jié)構(gòu)的改進,電容隔直法和直流分量檢測電路的改進等幾個方面著手消除直流分量。第四,在現(xiàn)有直流分量抑制方法的基礎(chǔ)上提出直流分量綜合抑制法,采用虛擬電容法和平均電流法相結(jié)合,在控制環(huán)中做兩級反饋,最終實現(xiàn)對直流分量的抑制。并設(shè)計仿真算例仿真驗證控制算法的可行性。
[Abstract]:Photovoltaic power generation is developing rapidly. As the main equipment of photovoltaic system, photovoltaic grid-connected inverter should be attached great importance to. DC components will be included in the AC power output of the inverter. These DC components will not only harm the equipment itself, but also seriously affect the power quality of the power grid. Therefore, it must be suppressed and compensated. Firstly, several kinds of photovoltaic inverter topology which are widely used in photovoltaic system are compared and analyzed in this paper. The AC output of isolated photovoltaic grid-connected inverter basically does not contain DC component, but the non-isolated grid-connected inverter will transmit DC component to the power network due to the lack of isolation function of isolation transformer. This paper summarizes the technical requirements of output DC component of photovoltaic grid-connected inverter at home and abroad, analyzes the generation mechanism of DC component of non-isolated grid-connected inverter and the harm of DC component to power grid equipment. The software DC component suppression method and the hardware DC component suppression method are analyzed. Thirdly, the existing DC component suppression methods are compared and analyzed. On the basis of the existing DC component suppression methods, a comprehensive DC component suppression method is proposed, which is based on the current DC component suppression method, and the improvement of the capacitance barrier method and the DC component detection circuit, etc., is taken to eliminate the DC component. The virtual capacitance method and the average current method are used to make two-stage feedback in the control loop, and finally the DC component is suppressed. A simulation example is designed to verify the feasibility of the control algorithm.
【學(xué)位授予單位】：華北電力大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TM464;TM615

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本文編號：1630706