【摘要】 对于直流离网光伏发电系统,当直流母线的功率需求较大时,因太阳能帆板的输出电压及功率受温度及光照的影响,需采用最大功率点跟踪(Maximum Power Point Tracing,MPPT)的方式使帆板始终保持最大功率输出的状态。而当直流母线的功率需求较小时,所有变换器同时工作将引起轻载效率低等问题,此时提高效率最简单直接的方法就是减少工作模块数量,从而确保系统在全功率范围内高效地实现能量变换。为解决上述问题,提出了发电系统的控制策略,该策略在满足电源系统负载需求的前提下,充分利用了帆板能量,并可根据负载需求动态调整工作模块数量,为提高直流离网光伏发电系统全负载范围内的运行效率提供了理论依据。最终通过仿真验证了该方案的有效性。更多还原

【Abstract】 For DC off-grid photovoltaic power generation system, when the power demand of DC bus is large, Maximum Power Point Tracing( MPPT) is needed to keep the solar panels in the state of maximum power output for the output voltage and power are affected by temperature and illumination evidently. When the power demand is small, all converters working at the same time will lead to low efficiency of light load. The most simple and direct way to improve is to reduce the number of working modules, so as to ensure that the power system can achieve energy conversion efficiently within the full range. In order to solve the above prob-lems, this paper proposes a control strategy for power generation system. This strategy makes full use of the solar array and adjusts the number of working modules dynamically according to the load demand. It provides a rationale for improving the operation effi-ciency of DC off-grid photovoltaic power generation system within the full load range. Finally, the effectiveness of the scheme is verified by simulations.更多还原