摘要
针对光伏并网逆变器,首先建立在数字控制下的z域模型,然后通过讨论其z域开环传递函数的频率特性,确定并网逆变器相位在不同谐振角频率区间穿越-180°的情况。同时结合奈奎斯特判据,给出光伏并网逆变器在不同谐振角频率区间的稳定判据,并根据此判据提出光伏并网逆变器优化设计思路与方法。该方法能够抵抗电网等效阻抗的宽范围变化,最后通过仿真和实验验证了理论分析的正确性。
For the photovoltaic grid-connected inverter,the z-domain model under digital control is established firstly.Then through the frequency characteristics of the z-domain open-loop transfer function,the conditions of?180°crossing in different ranges of resonance angle frequency are determined.Meanwhile,combined with Nyquist criterion,the stability conditions of grid-connected inverter in different ranges of resonance angle frequency are given.Accordingly,the optimized design idea and method of photovoltaic grid-connected inverter are put forward,which can resist the wide range changes of grid equivalent impedance.Finally,the theoretical analysis is verified by the simulation and experiment.
作者
郑堃
周林
张前进
解宝
李海啸
Zheng Kun;Zhou Lin;Zhang Qianjin;Xie Bao;Li Haixiao(State Key Laboratory of Power Transmission Equipment&System Security and New Technology,Chongqing University,Chongqing 400044 China)
出处
《电工技术学报》
EI
CSCD
北大核心
2018年第8期1802-1813,共12页
Transactions of China Electrotechnical Society
基金
国家自然科学基金资助项目(51477021)
关键词
数字控制
光伏
并网逆变器
稳定性分析
优化设计
电网阻抗
Digital control
photovoltaic
grid-connected inverter
stability analysis
optimized design
grid impedance
