摘要
本文针对应用于三相非隔离光伏并网发电逆变器中三电平Boost直流变换器启动建压过程时,可能出现的中点(Neural-Point, NP)电位不平衡问题和后级逆变电路调制策略对中点电位的影响,在三电平Boost直流变换器功率级提出了一种实现中点电位平衡的模糊控制策略。采用模糊控制器可自适应地改变三电平Boost直流变换器开关管的占空比大小,不仅在启动过程中(直流母线建压时),而且在并网逆变器稳定工作时,都能实现直流侧输出电容的均压,并获得良好的动态和静态性能。论文中为三电平Boost直流变换器设计了模糊控制器,给出了控制规则。最后通过仿真和实验验证了该方法的可行性和可靠性。
Aiming at the neutral-point(NP)imbalance and the influence of the modulation strategy of the post-stageinverters on the neutral-point potential when the three-level Boost DCconverter is used in the three-phase non-isolated grid-connected PV powergeneration inverters to start the voltage-building process,a fuzzy controlstrategy is proposed to realize the neutral-point potential balance at thepower level of the three-level Boost DC converter.The duty cycle ratio of theswitch of three-level Boost DC converter can be adaptively changed by using thefuzzy controller.Not only in the start-up process(when the DC bus isvoltage-building),but also in the stable operation of grid-connectedinverters,the voltages across output capacitors can be equalized and good dynamicand static performance is obtained.In this paper,a fuzzy controller isdesigned for three-level Boost DC converter,and the control rules are given.Finally,the feasibility and reliability of the method are verified bysimulation and experiment.
出处
《电路与系统》
2019年第3期56-66,共11页
Open Journal of Circuits and Systems
基金
国家自然科学基金(61873346)
国家电网扬州供电公司互联网研究院基金(SGTYHT/17-JS-202)
扬州大学江都高端装备工程技术研究院开放课题基金(YDJD201902)。
