發(fā)布時間：2019-05-24 18:14

【摘要】：隨著環(huán)境和能源問題日益凸顯,分布式發(fā)電技術(shù)越來越受到人們的重視。但是功率不可控的分布式電源接入后電網(wǎng),會出現(xiàn)很多不利影響。微網(wǎng)的出現(xiàn)在很大程度上解決了這個問題。研發(fā)一款教學(xué)用微網(wǎng)平臺,對于培養(yǎng)微網(wǎng)技術(shù)專業(yè)人才,具有重要意義。本文設(shè)計了一套教學(xué)用微網(wǎng)平臺。該微網(wǎng)平臺由儲能單元、實訓(xùn)試驗臺、光伏發(fā)電系統(tǒng)、風(fēng)力發(fā)電系統(tǒng)、負載模塊等子系統(tǒng)組成。其交流母線的線電壓為36V,通過隔離變壓器與市電網(wǎng)相連。該平臺采用主從控制結(jié)構(gòu),儲能單位作為微網(wǎng)平臺的主源,其余微源作為從源,可以正常工作于并網(wǎng)和離網(wǎng)兩種模式。并網(wǎng)運行時,所有微源均采用PQ控制方式,以單位功率因數(shù)的方式向電網(wǎng)輸出功率。孤網(wǎng)運行時,儲能單元作為主源,采用V/f控制方式,提供微網(wǎng)交流母線電壓和頻率的支撐,其余微源仍然采用PQ控制方式,微網(wǎng)平臺內(nèi)功率能夠維持平衡。教學(xué)用微網(wǎng)平臺在孤網(wǎng)時應(yīng)能正常運行,雙向逆變器是儲能單元與微網(wǎng)平臺連接的媒介,儲能單元又是微網(wǎng)平臺孤網(wǎng)運行時電壓和頻率支撐的提供者。因而,雙向逆變器對于微網(wǎng)平臺的正常運行至關(guān)重要。本文詳細分析了雙向逆變器的工作原理和空間矢量調(diào)制原理,搭建了雙向逆變器的數(shù)學(xué)模型,在此基礎(chǔ)上給出了雙向逆變器的參數(shù)設(shè)計值。通過控制雙向逆變器側(cè)的電流方向,可以實現(xiàn)能量以單位功率因數(shù)的方式雙向流動。雙向逆變器在微網(wǎng)平臺孤網(wǎng)運行時,工作于逆變模式,用以維持交流母線電壓和頻率的穩(wěn)定。微網(wǎng)平臺并網(wǎng)運行時,雙向逆變器可以按照需要工作于整流和逆變兩種模式,用于儲能單元的充放電。雙向逆變器比普通的并網(wǎng)逆變器多了整流的功能,通過程序上的改動,雙向逆變器還可以當做普通的并網(wǎng)逆變器使用。本文所設(shè)計的雙向逆變器的功率等級為100W,整流和逆變時并網(wǎng)電流波形畸變率均小于5%。最后,本文在Simulink中搭建了微網(wǎng)模型,并且設(shè)計了雙向逆變器的實驗樣機,通過仿真和樣機實驗驗證了設(shè)計的合理性。
[Abstract]:With the increasingly prominent problems of environment and energy, distributed power generation technology has been paid more and more attention. However, there will be a lot of adverse effects on the power grid after the uncontrollable distributed power supply is connected to the power grid. The emergence of microgrid has solved this problem to a great extent. It is of great significance to develop a teaching microgrid platform for the training of microgrid technical professionals. In this paper, a set of microgrid platform for teaching is designed. The microgrid platform is composed of energy storage unit, training test-bed, photovoltaic power generation system, wind power generation system, load module and so on. The line voltage of the AC bus is 36 V, which is connected to the city power grid through the isolation transformer. The platform adopts master-slave control structure, energy storage unit as the main source of micro-grid platform, and other micro-sources as slave sources, which can work normally in both grid-connected and off-grid modes. When connected to the grid, all microsources use PQ control mode to output power to the power grid in the form of unit power factor. When the isolated network is running, the energy storage unit acts as the main source and adopts V 鈮，

本文編號：2485078