光伏发电Z源逆变器能量成型控制策略研究

发布时间：2019-02-09 20:31

【摘要】：太阳能发电作为一种新能源发电具有很大的优势。其具有工作无噪声，便于小型化安装，适合贴近居民区安装等优势，因此得到了快速的发展。课题以太阳能发电为背景，研究了应用于太阳能发电的Z源并网逆变器的新型控制算法。通过分析Z源并网逆变器的发展现状，研究目前Z源并网逆变器控制策略的不足，分析能量成型控制策略的优势，结合Z源并网逆变器应用于光伏发电的特点，提出了采用能量成型控制策略进行Z源并网逆变器控制的研究。首先，对Z源逆变器的升压原理进行了阐述，详细分析了应用于Z源逆变器控制的三种升压调制策略，并结合SVPWM逆变调制方式将三种升压调制策略以直通时间的形式注入到SVPWM调制信号中。其次，对Z源并网逆变器的传统PI控制进行了研究。采用基于并网电流闭环的控制策略，分析了其并网控制的控制特性，，通过调节PI参数，可以使系统达到预期的控制目标；进一步分析了其孤岛运行状态，采用基于输出电压闭环的控制，可以使Z源并网逆变器工作于孤岛模式；在其并网和孤岛的切换中提出了修正调制信号控制和给定电流渐增控制，减小切换冲击。在PI控制中，总结了其不足，为能量成型控制器的提出奠定了基础。然后，通过分析能量成型控制策略的理论基础，结合Z源并网逆变器的特性，建立了其综合的端口受控哈密顿（PCH）模型。在PCH模型的基础上通过阻尼注入和互联矩阵的设计方法设计了Z源并网逆变器的能量成型控制器。通过仿真验证了控制器设计的正确性。在以上研究基础上，通过比较Z源并网逆变器的PI控制和能量成型控制得出了采用两种控制方法各自的优缺点。Z源并网逆变器的PI控制存在PI参数的调整费时耗力，且PI控制鲁棒性较差，经常出现输出饱和或振荡的情况，而能量成型控制器的参数可以通过数学模型计算得到，不需反复的试凑，且具有较好的鲁棒性。最后，通过建立光伏电池的仿真模型分析了其输出特性，对应用于光伏发电的MPPT控制策略进行了分析，在此基础上，结合能量成型控制器，将MPPT控制算法以差分方程的形式嵌入到能量成型控制器中，建立了采用能量成型控制算法的光伏发电Z源并网逆变器综合的控制器。系统整体的仿真结果证实了控制的有效性。
[Abstract]:Solar power generation as a new energy generation has great advantages. It has the advantages of no noise, miniaturization and close to residential area, so it has been developed rapidly. Based on the background of solar power generation, a new control algorithm of Z source grid-connected inverter for solar power generation is studied. Based on the analysis of the development of Z-source grid-connected inverter, the deficiency of current Z-source grid-connected inverter control strategy is studied, and the advantages of energy shaping control strategy are analyzed. The characteristics of Z-source grid-connected inverter applied in photovoltaic power generation are analyzed. The study of Z-source grid-connected inverter control using energy forming control strategy is presented. Firstly, the booster principle of Z-source inverter is described, and three kinds of boost modulation strategies are analyzed in detail. Combined with SVPWM inverter modulation, three boost modulation strategies are injected into the SVPWM modulation signal in the form of through time. Secondly, the traditional PI control of Z source grid-connected inverter is studied. Based on the closed-loop control strategy of grid-connected current, the control characteristics of grid-connected control are analyzed. By adjusting the parameters of PI, the desired control objectives can be achieved. Furthermore, the islanding operation state is analyzed, and the Z source grid-connected inverter can work in the isolated island mode by using the closed-loop control based on the output voltage. In the switching between grid-connected and islanding, modified modulation signal control and given current increasing control are proposed to reduce the switching impact. The deficiency of PI control is summarized, which lays a foundation for the development of energy forming controller. Then, by analyzing the theoretical basis of the energy shaping control strategy and combining the characteristics of Z-source grid-connected inverter, a comprehensive port controlled Hamiltonian (PCH) model is established. Based on the PCH model, the energy shaping controller of Z-source grid-connected inverter is designed by means of damping injection and interconnection matrix design. The correctness of the controller design is verified by simulation. On the basis of the above research, the advantages and disadvantages of the two control methods are obtained by comparing the PI control of Z-source grid-connected inverter and the control of energy shaping. The PI control of Z-source grid-connected inverter has the time-consuming and time-consuming adjustment of PI parameters. Moreover, the robustness of PI control is poor, the output saturation or oscillation often occurs, and the parameters of the energy forming controller can be calculated by mathematical model, without repeated trial and error, and have good robustness. Finally, the output characteristics of photovoltaic cell are analyzed by establishing the simulation model, and the MPPT control strategy applied to photovoltaic power generation is analyzed. On this basis, the controller is combined with the energy forming controller. The MPPT control algorithm is embedded in the energy forming controller in the form of difference equation, and the integrated controller of the photovoltaic Z-source grid-connected inverter using the energy shaping control algorithm is established. The simulation results of the whole system verify the effectiveness of the control.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM464

【参考文献】