【摘要】 微型光伏逆变器的稳定运行是其安全、可靠接入电网的一大要求,传统分析方法常采用状态空间平均模型研究微型光伏逆变器的稳定性。但这一传统模型忽略了电路中开关器件的切换过程,难以准确描述微型光伏逆变器的稳定性。针对这一问题,本文考虑开关切换过程,提出了一种z-s域建模方法。首先,分析微型光伏逆变器各个工作模态,列写出各个工作模态的离散迭代方程;其次,将微型光伏逆变器的状态变量分离为稳态量与扰动量,对各个工作模态的离散迭代方程进行线性化处理;然后,将线性离散迭代方程转换至频域,推导出z域传递函数,采用双线性变换法将模型从z域转换至s域,写出s域传递函数,进而得到微型光伏逆变器的z-s域模型;最后,通过与状态空间平均模型对比的仿真和实验,验证了所提出建模方法对微型光伏逆变器稳定性分析的正确性和有效性。更多还原

【Abstract】 The stable operation of micro photovoltaic inverter is a major requirement to connect to the power grid safely and reliably.The state space averaging model is one of traditional analysis models to study the stability of micro photovoltaic inverter.However,the state space averaging model ignores the switching process,which is difficult to accurately describe the stability of micro photovoltaic inverter.Thus,considering the switching process,a z-s domain modeling method is proposed.Firstly,each working mode of the micro photovoltaic inverter is analyzed,and the discrete iterative equations are listed.Secondly,the state variables are separated into steady state and disturbance,and the discrete iterative equations are linearized.Then,the linear discrete iterative equation is converted to the frequency domain,and the z-domain transfer function is derived.The model is converted from the z-domain to the s-domain by bilinear transformation method,and z-s domain model is obtained.Finally,the correctness and effectiveness of the proposed modeling method for the stability analysis of micro photovoltaic inverter is verified by simulation and experiments compared with the state space averaging model.更多还原