适用于新能源发电的两级式逆变器研究

发布时间：2018-03-23 02:14

本文选题：新能源发电　切入点：两级式逆变器　出处：《安徽工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着全球能源及环境问题的日益凸显,诸如光伏、燃料电池之类的新能源发电技术以其高效、无污染、不受地域限制等优点,正越来越多的被人们所关注。然而,通常情况下光伏、燃料电池输出电压都比较低,为了能将上述新能源发出的电能供给负载或者并入电网,通常需要一级DC/DC变换器先将较低的直流输入电压转换为较高的直流输出电压,之后再由逆变装置将直流电压转化为交流电压,以满足用电设备或者电网的要求。在此应用背景下,前级为高增益DC/DC变换器的两级式逆变器应运而生。针对前级DC/DC变换器输入电流纹波过大会造成新能源设备工作寿命缩短及发电效率降低的问题,本文首先提出了一种适用于新能源发电的零纹波改进交错Boost变换器,详细分析了该电路的工作原理和稳态特性。在此基础上,引入耦合电感技术和倍压单元技术,构成了另一种双耦合电感零纹波高增益变换器,分析了其工作原理与稳态特性,之后利用仿真初步验证了上述两个变换器理论分析的正确性。通过对后级DC/AC电路常用拓扑优缺点的比较,选择单相全桥逆变器作为后级主电路,简述了SPWM调制技术在DSP中的实现原理,基于逆变器的电压电流双闭环模型,设计了控制参数,并通过MATLAB/Simulink仿真验证了控制参数的有效性。为了对所研究两级式逆变器的稳定性进行分析,通过建立数学模型,首先推导出了前级DC/DC变换器的输出阻抗及后级DC/AC变换器的输入阻抗,采用阻抗比判据,研究了整个系统的稳定性,并分析了中间母线电容大小对系统稳定性的影响。最后,基于TMS320F2812DSP数字控制器搭建了两级式逆变器的原理样机,进行了实验验证,实验结果与理论分析有着很好的一致性。
[Abstract]:With the increasing global energy and environmental problems, new energy generation technologies, such as photovoltaic, fuel cells and other advantages of its efficiency, pollution-free, not subject to geographical restrictions, are being paid more and more attention. In general, photovoltaic and fuel cell output voltages are relatively low, in order to supply the electricity from the new energy sources mentioned above or to incorporate them into the power grid. It is usually necessary to convert the lower DC input voltage to the higher DC output voltage by the first DC/DC converter, and then convert the DC voltage to the AC voltage by the inverter. In order to meet the requirements of electrical equipment or power grid. In this application context, A two-stage inverter with a high gain DC/DC converter has emerged as the times require. In view of the problem that the input current ripple of the former DC/DC converter leads to the shortening of the working life of the new energy equipment and the reduction of the generation efficiency, In this paper, a novel zero-ripple modified interleaved Boost converter for new energy generation is proposed. The principle and steady-state characteristics of the circuit are analyzed in detail. On the basis of this, coupled inductance technology and voltage multiplier technique are introduced. Another dual-coupling inductor zero-ripple high gain converter is constructed. Its working principle and steady-state characteristics are analyzed. After that, the correctness of the theoretical analysis of the two converters is preliminarily verified by simulation. By comparing the advantages and disadvantages of the common topologies of the rear stage DC/AC circuits, the single-phase full-bridge inverter is selected as the rear stage main circuit. The realization principle of SPWM modulation technology in DSP is briefly introduced. Based on the voltage and current double closed loop model of inverter, the control parameters are designed. The effectiveness of the control parameters is verified by MATLAB/Simulink simulation. In order to analyze the stability of the studied two-stage inverter, a mathematical model is established. First, the output impedance of the former DC/DC converter and the input impedance of the DC/AC converter are derived. The stability of the whole system is studied by using the impedance ratio criterion, and the influence of the middle bus capacitance on the stability of the system is analyzed. The principle prototype of two-stage inverter is built based on TMS320F2812DSP digital controller, and the experimental results are verified by experiments. The experimental results are in good agreement with the theoretical analysis.
【学位授予单位】：安徽工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM464

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