基于DSP的光伏发电系统中最大功率点跟踪算法的研究

Research on MPPT method of photovoltaic power generation system based on DSP

基于DSP芯片TMS320F2812设计一种两级式光伏并网发电系统。对该系统提出了一种新型的MPPT控制算法,即在外界环境或负载突变时,先采用一种在线计算短路电流法,避免了对系统正常工作的干扰,以保证跟踪的快速性;在此基础上引入小步长的扰动观察法,对最大功率点处的稳态特性进行优化,可有效减小系统的输出功率在最大功率点的振荡现象。通过Matlab软件分别对扰动观察法、短路电流法以及所提的新型MPPT方法进行仿真,结果表明,该新型MPPT方法能够快速、准确地跟踪外部环境变化,减少了系统在最大功率点的振荡现象,提高了光伏发电系统的效率。

To design a two-stage photovoltaic power generation system based on the DSP chip of TMS320F2812. Proposed a new MPPT control algorithm in this system, that is when the external environment or load mutation, an on-line calculation of short-circuit current method is used first, avoid disturbance to the normal work of the system, in order to ensure fast tracking; small step perturbation and observation method is introduced on this basis, the steady state characteristics of the maximum power point is optimized, which can effectively reduce power output of the system in the oscillation phenomenon of maximum power point. Through Matlab software to respectively simulate the perturbation and observation method, short-circuit current method and the new MPPT method, the results show that the new MPPT method can track the changes in the external environment quickly and accurately, reduce the system oscillatory phenomena in the maximum power point, improve the egiciency of photovoltaic power generation system.