隔离型Z源光伏微逆变器全息建模及非线性控制研究

In order to improve efficiency and reliability for the photovoltaic micro inverter, as a result of analyzing the performance of existing micro inverter topology, the isolated Z-source circuit topology under high frequency is proposed in this project; Based on the analysis of the circuit structure, working mode, the relationship between transient variables and system parameters during the commutation process, the holographic precise linearization mathematical model including uncertainty will be studied. According to the un-modeled disturbance suffered by the micro inverter and the characteristics of nonlinear non-minimum phase in Z-source topology, the nonlinear control strategy will be proposed to realize the DC-link boost and the grid-tie control. Due to the system control affected by the coupling parameter of Z-source topology under multiple mode, the general affect mechanism about coupling parameter of isolated Z-source circuit topology working on the control system under multiple mode will be studied. According to the analysis on the whole power loss and the circuit parameters changing impact on steady-state and transient performance of the system, the whole micro inverter will be optimized to make the circuit working in the soft switch state, and establish the conducted EMI model which can provide theoretical guidance for conducted EMI filter design. This project will further promote the development of micro inverter in photovoltaic field, at the same time the new topology will be added into the Z-source topology family.

针对如何提高光伏微逆变器的效率和可靠性，对已有微逆变器拓扑的性能进行比较，研究高频工作条件下的隔离型Z源电路拓扑；在分析变换器电路结构、工作模式、换流过程暂态变量与微逆变器系统各参数关系的基础上，提出含不确定性高频寄生参数的系统全息精确线性化数学模型；针对微逆变器系统受到的未建模干扰及Z源拓扑的非线性非最小相位特性，分析多模式下Z源拓扑耦合参数对系统控制影响，研究一般隔离型Z源结构耦合参数在多模式下对系统控制的影响机理，提出非线性控制策略实现直流链升压和并网电流两级控制；在对整个系统综合功率损耗分析及电路参数变化对系统稳态及暂态性能影响的基础上，对微型逆变器系统进行参数优化设计，使电路工作在软开管状态并构建适用于高频隔离型Z源微逆变器的传导EMI分析模型，为系统传导EMI滤波设计提供理论指导。本项目能进一步推动微逆变器在光伏领域的发展，同时能对Z源拓扑族进行增补。

本项目针对现有的光伏微逆变器如何提高效率和可靠性的问题，提出高频隔离准Z源微逆变器拓扑。对该拓扑电路结构、工作模式与系统各参数的关系分析，以及系统受到的未建模干扰及 Z 源拓扑的非线性非最小相位特性，用非线性控制策略实现直流链升压和并网电流两级控制；提出了适用于隔离型 Z 源拓扑微逆变器的 EMI 抑制手段；整个系统电路中典型参数对系统稳态及暂态性能的影响，优化整个微逆变器系统，搭建实验样机，完成测试、分析和评估。这一理论方法最终实现了光伏并网微型逆变器高效率、高可靠、控制灵活、输出电能质量高的功能，一方面不仅推动微逆变器在光伏领域的发展，还能使 Z 源拓扑族进行增补。本项目对所研究的隔离型准Z源型逆变器，通过Matlab/Simulink、Saber、RT-LAB等仿真及实验验证了所提出控制方法的控制效果和控制系统的稳定性、鲁棒性，所研究的的混沌扩频技术降低电路中传导EMI峰值的有效性，提出的非线性滑模控制方法和Chen系统多卷波混沌EMI抑制方法具有较好的控制效果，具有较好的工程应用前景。