本文選題：微電網(wǎng) + 多功能并網(wǎng)逆變器　； 參考：《湖南大學》2016年碩士論文

【摘要】：如今全球能源危機和環(huán)境污染的問題日益加劇,充分利用光伏、風力等清潔可再生能源發(fā)電是未來電網(wǎng)發(fā)展的必然趨勢,微電網(wǎng)作為一種分布式電源接入電網(wǎng)的有效手段,逐步引起了廣泛的關注。微電網(wǎng)中的并網(wǎng)逆變器是能量傳輸?shù)年P鍵裝置,具有與電能質(zhì)量治理裝置類似的拓撲結構和靈活多樣的控制策略,可以主動參與微電網(wǎng)電能質(zhì)量治理,研究多功能并網(wǎng)逆變器的控制策略,提升逆變器在弱電網(wǎng)下的適應能力,對微電網(wǎng)穩(wěn)定可靠運行具有重要的意義。本文以微電網(wǎng)中多功能并網(wǎng)逆變器的控制策略為對象,深入研究了多功能并網(wǎng)逆變器的同步鎖相環(huán)控制方法和不平衡及諧波的補償策略。主要工作和創(chuàng)新點體現(xiàn)在：(1)在分析同步參考坐標系鎖相環(huán)的數(shù)學模型和動態(tài)性能基礎上,分別研究了基于二階廣義積分和滑動平均濾波的正負序解耦方法。詳細闡述了兩種濾波策略的結構、參數(shù)選擇與動態(tài)性能,基于兩種濾波方法,分別設計了dq旋轉坐標系下的鎖相環(huán)結構。通過仿真驗證,兩種正負序解耦方法能夠精確地檢測電網(wǎng)電壓基波的正負序幅值和相位信息,消除了電網(wǎng)電壓不平衡和諧波對同步信號檢測的影響。其中基于滑動平均濾波的正負序解耦方法結構更加簡單、響應速度更快、諧波抑制能力更強。(2)針對微電網(wǎng)中的電網(wǎng)電壓不平衡和非線性負載諧波問題,本文提出了一種多功能并網(wǎng)逆變器綜合集成控制方法,實現(xiàn)對正、負序下的基波有功、無功及諧波綜合控制。首先在電網(wǎng)電壓不平衡下,研究了一種正序dq旋轉坐標系的電流聯(lián)合控制方法,實現(xiàn)對正序負序電流的控制,提高系統(tǒng)的響應性能。針對非線性負載諧波問題,提出一種諧波復合補償控制方法,將6k±1次特征諧波變換成dq旋轉坐標系下6k次諧波,旨在降低系統(tǒng)的復雜度。然后對基波、2次紋波和6k次指令電流疊加,通過比例諧振控制器實現(xiàn)綜合集成控制。最后通過仿真驗證了所提出控制策略的有效性。(3)研制了額定功率為50kW的多功能并網(wǎng)逆變器,并給出實驗裝置的硬件系統(tǒng)、控制系統(tǒng)和軟件系統(tǒng)的設計方案。通過對所開發(fā)的樣機進行測試,在電網(wǎng)電壓不平衡和非線性負載諧波下,所提出的控制策略能有效地抑制逆變器直流側二次紋波,并能對無功與諧波進行補償,提高了微電網(wǎng)的電能質(zhì)量。
[Abstract]:Nowadays, the global energy crisis and environmental pollution are becoming more and more serious. Making full use of clean and renewable energy, such as photovoltaic and wind, is the inevitable trend of the development of power grid in the future. Microgrid is an effective means of connecting distributed generation to power grid. Gradually aroused widespread concern. Grid-connected inverter in microgrid is the key device for energy transmission. It has similar topology structure and flexible control strategy as power quality control device, so it can participate in power quality management of microgrid actively. It is of great significance to study the control strategy of multi-function grid-connected inverter and improve the adaptability of inverter under weak grid, which is of great significance to the stable and reliable operation of microgrid. Taking the control strategy of multifunctional grid-connected inverter in microgrid as an object, the synchronous phase-locked loop control method and unbalanced and harmonic compensation strategy of multi-function grid-connected inverter are studied in this paper. On the basis of analyzing the mathematical model and dynamic performance of phase locked loop in synchronous reference coordinate system, the positive and negative sequence decoupling methods based on second order generalized integral and moving average filter are studied respectively. The structure, parameter selection and dynamic performance of the two filtering strategies are described in detail. Based on the two filtering methods, the phase-locked loop structure in the dq rotating coordinate system is designed respectively. The simulation results show that the two positive and negative sequence decoupling methods can accurately detect the amplitude and phase information of the fundamental wave of grid voltage and eliminate the influence of voltage imbalance and harmonics on the detection of synchronous signals. The method of positive and negative sequence decoupling based on moving average filter is simpler in structure, faster in response speed and stronger in harmonic suppression ability. In this paper, a comprehensive integrated control method for multifunctional grid-connected inverters is proposed to realize the integrated control of active, reactive and harmonic waves under positive and negative sequence. In this paper, a combined current control method based on the positive sequence DQ rotating coordinate system is studied under the unbalanced voltage of the power network, which realizes the control of the positive sequence and negative sequence current and improves the response performance of the system. In order to reduce the complexity of the system, a hybrid harmonic compensation control method is proposed to solve the nonlinear load harmonic problem. The 6k harmonic is transformed from 6k 鹵1 characteristic harmonics to 6k harmonics in the dq rotating coordinate system in order to reduce the complexity of the system. Then the fundamental ripple and 6k instruction current are superposed and the integrated control is realized by the proportional resonance controller. Finally, the effectiveness of the proposed control strategy is verified by simulation. The multifunctional grid-connected inverter with rated power of 50kW is developed, and the design scheme of hardware system, control system and software system of the experimental device is given. By testing the developed prototype, the proposed control strategy can effectively suppress the secondary ripple of the inverter and compensate the reactive power and harmonic under the unbalanced voltage and nonlinear load harmonics. The power quality of microgrid is improved.
【學位授予單位】：湖南大學
【學位級別】：碩士
【學位授予年份】：2016
【分類號】：TM464
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本文編號：2012506