摘要
为了提高光伏并网微逆变器的性价比,研究了一种采用阻塞二极管和偏置二极管相组合的电流采样电路,实现了无额外电流传感器的峰值电流采样,在此基础上研究了无电压、无电流传感器的最大功率点跟踪(Maximum Power Point Tracking, MPPT)方法,并提出了基于电网半周期内峰值电流采样值之和的MPPT扰动算法,产生并网电流的给定值,基于这一并网电流给定值设计了占空比观测器,从而实现了并网微逆变器的开环控制。文中研究的控制方法可在较低成本的控制芯片中实现,程序算法简单、硬件成本低。实验验证了本文研究方法的可行性,从而获得了高可靠性和高性价比。
In order to improve the performance-cost ratio of photovoltaic grid-connected micro-inverters,a current sampling circuit using blocking diode and bias diode is adopted,and the peak current sampling without additional current sensor is realized.Based on this,the maximum power point tracking(MPPT)method without voltage and current sensor is studied,and an MPPT disturbance algorithm based on the sum of peak current sampling values in half cycle of power grid is proposed to generate the given value of grid-connected current.Based on the given value of grid-connected current,a duty cycle observer is designed to realize the open-loop control of grid-connected micro-inverters.The control method studied in this paper can be implemented in a low cost control chip.The program algorithm is simple and the hardware cost is low.Experiments verify the feasibility of the research method in this paper,thus achieving high reliability and cost performance.
基金
国家自然科学基金(61873346)
扬州市厅科技合作资金计划(YZ2018136)
国家电网扬州供电公司互联网研究院基金(SGTYHT/17-JS-202)
江苏省研究生科研与实践创新训练计划项目(SJCX17_0624)。
