基于电压闭环及dp/du补偿的单级光伏MPPT技术

Single-stage Photovoltaic Inverter System and MPPT Technology Based on Voltage Loop and dp/du Compensation

在单级式光伏并网逆变系统结构基础上,提出一种新型的基于电压闭环和dp/du补偿的最大功率点跟踪(MPPT)技术。该算法在工作点偏离最大功率点时,能根据dp/du的变化快速跟踪最大功率点(MPP)处电压值,并将此给定电压与实际电压值之差经过PI运算得到实际应给定的交流输出电流幅值。通过仿真分析可知,无论在光照突变或渐变、增强或减弱时,该算法均能使系统准确快速地跟踪在MPP处。实验室建立了3 kW单级式光伏逆变系统,应用全数字化DSP控制技术和新型MPPT算法,实现了系统MPPT目标,最终并网可靠运行。

This paper proposes a new MPPT technology based on voltage loop and dp/du compensation.When working point has deviated from maximum power point,accord-ing to the change of dp/du,the new MPP voltage is fixed and by the PI calculation from the error between the new voltage and actual voltage,the result is given to output current amplitude of AC inverter.Through simulation of Mat-lab/simulink analysis,whichever state there is,sudden or gradual change of sunlight,increased or weaken radiation,the system is always able to run at MPP accurately.Besides,labora-tory establishes single-stage photovoltaic inverter system of 3 kW.By application of all digital DSP control technology and new MPPT algorithm,MPPT target is achieved,running stably.