共查询到17条相似文献,搜索用时 48 毫秒
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基于中值步长法的光伏阵列最大功率点跟踪 总被引:1,自引:0,他引:1
提出了光伏阵列最大功率点跟踪的新型变步长扰动观察法,即中值步长法。在外界环境发生变化时,利用斜率判断扰动方向,利用启动步长快速跟踪光伏阵列最大功率点的大概位置;然后每扰动一次就将扰动步长取中值,使系统在稳态时最大限度地逼近最大功率点,减小最大功率点附近的震荡,提高跟踪精度;利用功率判断避免在扰动过程中出现算法错误。通过Matlab进行仿真,证明了中值步长法能达到理想的跟踪效果。 相似文献
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光伏发电系统MPPT改进方法研究 总被引:1,自引:0,他引:1
研究了适合最大功率跟踪算法的新型变步长和改进型扰动观察法,以及将目标点扩展为一个区域的概念。改进最大功率跟踪方法,可有效应对光伏阵列的非线性和时变性,提高系统的有效产能,针对经典扰动观察法存在的振荡、误判问题,考虑到光伏阵列输出曲线最大功率点两侧斜率变化不一致和P-V曲线在工作区间内单峰性的特点。仿真结果表明,该方法提高了系统的稳定性和跟踪速度,在PSCAD环境下建立的三相并网系统中也得到了良好的仿真曲线,提高了光伏并网系统对光能的利用率,对并网电能质量方面的问题产生了积极作用。 相似文献
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针对传统扰动观察法(PO)步长不易确定、跟踪速度和稳态时功率振荡之间的固有矛盾,提出一种新型自适应扰动观察法,该算法依据功率的变化生成电压扰动值,保证电压指令对功率变化的快速跟踪,再根据光伏阵列电压指令值和实际值的误差产生DC-DC变换器所需要的占空比信号d,实现了真正的自适应扰动,而且跟踪速度快、稳态精度高,系统通用性强。同时给出所提出MPPT算法的详细设计步骤,并对新型自适应扰动观察法和传统扰动观察法在相同环境下进行仿真和实验比较,结果证明所提出算法的准确性和有效性。 相似文献
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针对常规固定步长扰动观察法步长难以确定和以光伏电池P-U曲线的斜率dP/dV作为变步长具有波动性大而导致震荡的缺点,提出了以dP/P作为步长变化控制量的改进变步长扰动观察法。仿真结果表明,改进变步长方法很好地解决了固定步长动态性能和稳定性能不能兼顾和以dP/dV作为变步长的方法存在功率震荡的问题,提高了光伏发电的转换效率。 相似文献
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This paper addresses the development of new variable step size fuzzy based MPPT controller. In this study, the fuzzy logic approach is firstly used to auto-scale the variable step size of the Incremental Conductance (IC) MPPT controller. Secondly, the proposed variable step size fuzzy based MPPT controller is used to track the output power of the PEM fuel cell system composed of 7 kW fuel cell supplying a 50Ω resistive load via a DC-DC boost converter controlled using the proposed MPPT. The proposed variable step size fuzzy-based MPPT controller is compared to the conventional fixed step size IC, the variable step size IC and the fuzzy scaled variable step size IC MPPTs using the implemented Matlab/Simulink PEM Fuel Cell power system model. Comparative simulation results between the four studied MPPTs show better performances for the proposed fuzzy based variable step size MPPT in term of: response time reduction between 3.6% and 82.35%; overshoot reduction between 34.55% and 100%; and ripple reduction between 70.93% and 100%, improving as consequence the fuel cell lifetime affected by high current ripple. 相似文献
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B. Tartakovsky P. MehtaG. Santoyo S.R. Guiot 《International Journal of Hydrogen Energy》2011,36(17):10557-10564
This study describes a novel method for controlling applied voltage in a microbial electrolysis cell (MEC). It is demonstrated that the rate of hydrogen production could be maximized without excessive energy consumption by minimizing the apparent resistance of the MEC. A perturbation and observation algorithm is used to track the minimal apparent resistance by adjusting the applied voltage. The algorithm was tested in laboratory-scale MECs fed with acetate or synthetic wastewater. In all tests, changes in MEC performance caused by the variations in organic load, carbon source properties, and hydraulic retention time were successfully followed by the minimal resistance tracking algorithm resulting in maximum hydrogen production, while avoiding excessive power consumption. The proposed method of real-time applied voltage optimization might be instrumental in developing industrial scale MEC-based technologies for treating wastewaters with varying composition. 相似文献
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