摘要
以扰动观察最大功率点跟踪(MPPT)方法为例,全面分析了功率采样周期、功率扰动步长、直流母线电容容值等因素对系统稳定性影响。分析表明,即使在光照不突变且最大功率算法不出现误判的情况下,功率采样周期过大、直流母线电容容值过小或扰动步长过大,仍将导致直流母线电压出现崩溃性跌落,并导致系统失稳。考虑到实际系统中增加直流母线电容容值带来高昂的硬件成本,结合此处分析结果,给出功率采样周期和功率扰动步长设计方法。最后,在一个640 kWp的光伏并网系统中验证了分析结果。
Taking the maximum power point tracking(MPPT)method of disturbance observation as an example,the influence of power sampling period,power disturbance step length,DC busbar capacitance and other factors on the system stability is analyzed.The analysis shows that even if the illumination does not change suddenly and the maximum power algorithm does not misjudge,the large power sampling period,the small capacitance value of the DC bus or the large disturbance step size will still lead to the collapse drop of the DC bus voltage and the instability of the system.Considering the high hardware cost of increasing the capacitance of the DC bus in the actual system,the design method of power sampling period and power disturbance step size is given based on the analysis results.Finally,the analysis results are verified in a 640 kWp grid-connected photovoltaic system.
作者
言大伟
高昱峰
沈志强
YAN Da-wei;GAO Yu-feng;SHEN Zhi-qiang(Stale Grid Zhejiang Hangzhou Power Supply Company,Hangzhou 310000,China)
出处
《电力电子技术》
CSCD
北大核心
2020年第11期73-76,124,共5页
Power Electronics
关键词
逆变器
光伏并网
最大功率点跟踪
inverter
photovoltaic grid-connected
maximum power point tracking
