【摘要】：近年來，各國都加大了對太陽能、風(fēng)能、地?zé)�、潮汐等新能源的開發(fā)和利用，然而，分布式電源所發(fā)出的直流電無法直接供給電網(wǎng)和交流負載，必須經(jīng)過一定的接口設(shè)備方可實現(xiàn)并網(wǎng)，光伏(PV)發(fā)電并網(wǎng)通常采用的是電壓源型電流控制逆變器。目前，LCL濾波型并網(wǎng)逆變器受到廣泛應(yīng)用，但是其結(jié)構(gòu)決定了它會產(chǎn)生諧振，使得并網(wǎng)電流THD升高，甚至使其無法滿足并網(wǎng)條件，為了保證并網(wǎng)電流質(zhì)量，必須采取措施抑制諧振。此外，并網(wǎng)逆變器要想實現(xiàn)高效率并網(wǎng)，還必須保證并網(wǎng)電流與電網(wǎng)電壓同頻同相，因此同步鎖相技術(shù)的研究尤為重要。所以，光伏并網(wǎng)逆變器如何實現(xiàn)諧振抑制與電網(wǎng)同步技術(shù)是本文的研究重點。 本文從分析光伏發(fā)電原理及其數(shù)學(xué)模型入手，搭建了通用性很強的光伏電池模型，通過仿真對光伏電池特性以及擾動觀察法進行了研究。建立了LCL型光伏并網(wǎng)逆變器模型，給出了LCL濾波參數(shù)的設(shè)計，，為研究光伏并網(wǎng)逆變器運行奠定了基礎(chǔ)。 詳細分析了并網(wǎng)運行時采用的SVPWM調(diào)制策略和PQ控制方法，根據(jù)他們的實現(xiàn)原理建立了各自的仿真模型，通過仿真驗證這兩種控制模型的正確性，為并網(wǎng)運行提供了控制方法。 針對LCL型光伏并網(wǎng)逆變器產(chǎn)生的諧振問題，采用阻尼控制策略，分別分析了電容支路串聯(lián)電阻的無源阻尼法以及電容電流反饋的有源阻尼法機理，仿真從并網(wǎng)電流波形質(zhì)量和諧波頻譜方面驗證了他們具有良好的諧振抑制效果。研究了逆變器功率變化時采用無源/有源阻尼雙模式控制方法，對其切換過程進行了仿真，驗證了其切換過程平滑，并網(wǎng)電流THD符合并網(wǎng)條件，方案具有可行性。 分析了SSRF SPLL原理并進行了常見電網(wǎng)狀況下的仿真，其在電網(wǎng)電壓幅值不平衡和單相接地故障時鎖相性能不理想，隨后根據(jù)DDSRF SPLL鎖相原理，建立解耦模型，通過仿真驗證DDSR SPLL能夠解決電網(wǎng)電壓幅值不平衡及單相接地故障時的鎖相問題。通過理論分析得到PI控制下并網(wǎng)電流與電網(wǎng)電壓之間存在相位差，針對該問題采用相位補償?shù)姆椒▽崿F(xiàn)并網(wǎng)電流與電網(wǎng)電壓準確同步，保證了單位功率因數(shù)并網(wǎng)，仿真結(jié)果驗證了方案的正確性。
[Abstract]:In recent years, countries have increased the development and utilization of new energy sources, such as solar energy, wind energy, geothermal energy, tidal energy, and so on. However, the direct current emitted by distributed power sources cannot be directly supplied to the grid and AC load. Grid-connected photovoltaic (PV) is usually connected with a voltage-source current-controlled inverter. At present, LCL filter grid-connected inverter is widely used, but its structure determines that it will produce resonance, make the grid-connected current THD increase, even make it unable to meet the grid-connected conditions, in order to ensure the quality of grid-connected current, Measures must be taken to suppress resonance. In addition, in order to achieve high-efficiency grid-connected inverter, grid-connected current and grid voltage must be in the same frequency and phase, so the research of synchronous phase-locked technology is particularly important. Therefore, how to achieve resonance suppression and grid synchronization technology of photovoltaic grid-connected inverter is the focus of this paper. Based on the analysis of the principle and mathematical model of photovoltaic power generation, a photovoltaic cell model with strong generality is built in this paper. The characteristics and disturbance observation method of photovoltaic cell are studied by simulation. The model of LCL photovoltaic grid-connected inverter is established, and the design of LCL filter parameters is given, which lays a foundation for studying the operation of photovoltaic grid-connected inverter. The SVPWM modulation strategy and PQ control method used in grid-connected operation are analyzed in detail, and their simulation models are established according to their realization principle. The correctness of these two control models is verified by simulation, which provides a control method for grid-connected operation. In order to solve the resonance problem of LCL photovoltaic grid-connected inverter, the passive damping method of capacitor branch series resistance and the active damping method of capacitor current feedback are analyzed by using damping control strategy. The simulation results show that the grid-connected current waveform quality and harmonic spectrum show that they have good resonance suppression effect. The passive / active damping dual-mode control method for inverter power change is studied. The simulation results show that the switching process is smooth and the grid-connected current THD accords with the grid-connected condition. The scheme is feasible. In this paper, the principle of SSRF SPLL is analyzed and the simulation of common grid conditions is carried out. The phase locking performance is not satisfactory when the voltage amplitude is unbalanced and the single phase to ground fault. Then, according to the principle of DDSRF SPLL phase locking, the decoupling model is established. The simulation results show that DDSR SPLL can solve the phase-locked problem of unbalanced voltage amplitude and single-phase-to-earth fault. The phase difference between grid-connected current and grid voltage under the control of PI is obtained by theoretical analysis. Aiming at this problem, phase compensation is adopted to realize accurate synchronization between grid-connected current and grid voltage, and the unit power factor is guaranteed to be connected to the grid. The simulation results verify the correctness of the scheme.
【學(xué)位授予單位】：燕山大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TM464;TM615

【參考文獻】

相關(guān)期刊論文 前10條

1 毛鴻,吳兆麟,王毅,劉樹林;三相電壓型PWM整流器無電流傳感器控制策略研究[J];電工技術(shù)學(xué)報;2001年02期

2 郭小強;鄔偉揚;趙清林;;新型并網(wǎng)逆變器控制策略比較和數(shù)字實現(xiàn)[J];電工技術(shù)學(xué)報;2007年05期

3 劉飛;查曉明;段善旭;;三相并網(wǎng)逆變器LCL濾波器的參數(shù)設(shè)計與研究[J];電工技術(shù)學(xué)報;2010年03期

4 楊永恒;周克亮;;光伏電池建模及MPPT控制策略[J];電工技術(shù)學(xué)報;2011年S1期

5 馬兆彪;惠晶;潘建;;基于重復(fù)PI控制的光伏并網(wǎng)逆變器的研究[J];電力電子技術(shù);2008年03期

6 張彥;趙義術(shù);余蜜;熊健;;光伏并網(wǎng)逆變器電流控制技術(shù)研究[J];電力電子技術(shù);2009年05期

7 臧殿紅;康忠健;趙有俊;;有源補償零磁通電流傳感器的研制[J];電力電子技術(shù);2009年06期

8 杜少武;趙欽;張勝;;太陽能并網(wǎng)輸出LCL濾波器的設(shè)計[J];電力電子技術(shù);2009年11期

9 芮騏驊;杜少武;姜衛(wèi)東;趙欽;;三相光伏并網(wǎng)逆變器SVPWM電流控制技術(shù)研究[J];電力電子技術(shù);2010年04期

10 呂志鵬;羅安;榮飛;郭镥;;電網(wǎng)電壓不平衡條件下微網(wǎng)PQ控制策略研究[J];電力電子技術(shù);2010年06期

本文編號：2446692