基于SiC的光伏并网逆变器的研究

发布时间：2018-01-14 13:19

本文关键词：基于SiC的光伏并网逆变器的研究　出处：《湖北工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：当今,随着经济全球化和工业化进程快速发展,能源危机和环境污染是制约可持续发展的两大重要因素,而且,可利用的化石能源在不久的将来会消耗殆尽,因此寻找可再生能源代替化石能源是发展的趋势,太阳能发电因以其无污染、资源丰富、可靠等优点成为各国的必然选择。本文以单相两级非隔离光伏并网逆变器为研究对象,前级DC/DC变换器采用Boost升压电路来实现最大功率点跟踪控制,后级采用H桥逆变电路来实现并网控制。首先分析了太阳能阵列发电的原理,重点研究了太阳能电池的数学模型,并分析了几种常用MPPT控制的原理,在此基础上,结合PO算法,介绍了Boost电路的小信号模型,讨论了PO算法的最小步长和调节时间的选取,本文最大功率点跟踪采用恒定电压法与自适应变步长的PO算法相结合,并通过仿真验证,比较了自适应PO算法和定步长PO算法的优缺点。其次研究分析了并网锁相的控制策略,根据电路拓扑建立等效数学模型,在此基础上,针对电流环采用比例积分控制不能消除稳态误差和重复控制因周期性延时导致系统动态响应慢的缺点,本文电流环采用重复与PI并联的控制和鲁棒控制,并给出了控制框图,分别利用Matlab/Simulink进行仿真验证,得出PI控制与重复控制和鲁棒控制与重复控制能显著性的改善注入电网电流的THD,抑制系统低频谐波。然后设计了单相光伏硬件系统,并对硬件参数进行计算,主要包括开关管的选型、滤波电路、驱动电路、保护电路、检测电路、缓冲电路等参数设计等,控制器的控制芯片选为TI公司的DSP2812,软件主要包含主程序、AD采样程序、电网频率捕获程序、逆变程序等。最后根据理论计算搭建了实验样机,验证了硬件电路和控制算法的可行性,测试结果表明样机运行稳定,安全可靠,有良好的性能,并网电流质量好。
[Abstract]:Nowadays, with the rapid development of economic globalization and industrialization, the energy crisis and environmental pollution are two important factors restricting the sustainable development and use of fossil energy will be exhausted in the near future, so looking for renewable energy instead of fossil energy is the development trend of solar power generation due to its non pollution, abundant resources. The advantages of reliable become an inevitable choice. Based on the single phase two stage transformerless PV grid connected inverter as the research object, the DC/DC converter uses Boost circuit to achieve maximum power point tracking control, after using H bridge inverter circuit to realize grid control. This paper analyzes the principle of solar array power, focus on the mathematical model of the solar cell, and analyzes the principle of several commonly used MPPT control, on this basis, combined with the PO algorithm, the small signal Boost circuit The model, discussed the minimum step size PO algorithm and adjusting time of selection, the maximum power point tracking PO algorithm using the constant voltage method with variable step size adaptive combination, and through the simulation, comparing the advantages and disadvantages of adaptive PO algorithm and fixed step PO algorithm. Then study the control strategy of grid connected phase, according to the the establishment of mathematical model of equivalent circuit topology, on this basis, according to the current loop proportional integral control and repetitive control is not due to periodic delay lead to the shortcomings of slow dynamic response of the current loop to eliminate the steady-state error control and robust control and PI parallel with repetition, and gives the control diagram, respectively using Matlab/Simulink simulation come, PI control and repetitive control and robust control and repetitive control can significantly improve the current injected into the power system of THD, and then set the low frequency harmonic suppression system. The single-phase photovoltaic hardware system, and the hardware parameters, including switch selection, filter circuit, drive circuit, protection circuit, detection circuit, buffer circuit parameter design, control chip controller is selected as TI, DSP2812, software mainly includes the main program, AD sampling procedures, power grid frequency acquisition procedures, procedures and so on. Finally, the inverter experimental prototype is built based on the theoretical calculation, to verify the feasibility of hardware circuit and control algorithm, test results show that the prototype is stable, safe and reliable, has a good performance, and the current network of good quality.

【学位授予单位】：湖北工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM464

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