A novel maximum power-point tracking approach is proposed based on studies investigating the output characteristics of photovoltaic(PV)systems under partial shading conditions.The existence of partially shaded conditi...A novel maximum power-point tracking approach is proposed based on studies investigating the output characteristics of photovoltaic(PV)systems under partial shading conditions.The existence of partially shaded conditions leads to the presence of several peaks on PV curves,which decrease the efficiency of conventional techniques.Hence,the proposed algorithm,which is based on the modified particle-swarm optimization(MPSO)technique,increases the output power of PV systems under such abnormal conditions and has a better performance compared to other methods.The proposed method is examined under several scenarios for partial shading condition and non-uniform irradiation levels using Matlab,and to investigate its effectiveness adequately,the results of the proposed method are compared with those of the neural network technique.The experimental results show that the proposed method can decrease the interference of the local maximum power-point to cause the PV system to operate at a global maximum power-point.The efficiency of the MPSO is achieved with the least number of steady-state oscillations under partial shading conditions compared with the neural network method.展开更多
薄壁金属管是发生碰撞时为安全性所设置的关键吸能构件。为了提高薄壁管结构的耐撞性,结合方管的易安装性和圆管的稳定性,基于方竹结构对薄壁管截面进行耐撞性分析和仿生优化设计。通过对方竹结构的原型分析,利用ABAQUS搭建了仿方竹结...薄壁金属管是发生碰撞时为安全性所设置的关键吸能构件。为了提高薄壁管结构的耐撞性,结合方管的易安装性和圆管的稳定性,基于方竹结构对薄壁管截面进行耐撞性分析和仿生优化设计。通过对方竹结构的原型分析,利用ABAQUS搭建了仿方竹结构薄壁管有限元分析模型,在对模型进行试验验证的基础上,以壁厚、肋长为研究参数对仿方竹薄壁管耐撞特性进行了仿真分析。在此基础上,采用全因子试验设计方法来构建响应面模型,以比吸能和初始峰值载荷为目标函数,运用多目标粒子群优化算法进行优化求解并获得最优解的Pareto集。研究结果表明:仿方竹结构薄壁管有较好的耐撞性和稳定性,壁厚0.892 mm、肋长2.995 mm为仿方竹结构的最优解,此时初始峰值载荷和比吸能分别为10 k N和7.936598 k J/kg。研究结果对薄壁管的结构设计和尺寸优化具有重要意义。展开更多
基金Supported by the Hubei Provincial Natural Science Foundation of China(2015CFA010)the Technology Project of State Grid Company“Soft Connection Mechanism and Modeling of Smart Grid Adapting to the Development of Global Energy Interconnection”the 111 Projects(B17040).
文摘A novel maximum power-point tracking approach is proposed based on studies investigating the output characteristics of photovoltaic(PV)systems under partial shading conditions.The existence of partially shaded conditions leads to the presence of several peaks on PV curves,which decrease the efficiency of conventional techniques.Hence,the proposed algorithm,which is based on the modified particle-swarm optimization(MPSO)technique,increases the output power of PV systems under such abnormal conditions and has a better performance compared to other methods.The proposed method is examined under several scenarios for partial shading condition and non-uniform irradiation levels using Matlab,and to investigate its effectiveness adequately,the results of the proposed method are compared with those of the neural network technique.The experimental results show that the proposed method can decrease the interference of the local maximum power-point to cause the PV system to operate at a global maximum power-point.The efficiency of the MPSO is achieved with the least number of steady-state oscillations under partial shading conditions compared with the neural network method.
文摘薄壁金属管是发生碰撞时为安全性所设置的关键吸能构件。为了提高薄壁管结构的耐撞性,结合方管的易安装性和圆管的稳定性,基于方竹结构对薄壁管截面进行耐撞性分析和仿生优化设计。通过对方竹结构的原型分析,利用ABAQUS搭建了仿方竹结构薄壁管有限元分析模型,在对模型进行试验验证的基础上,以壁厚、肋长为研究参数对仿方竹薄壁管耐撞特性进行了仿真分析。在此基础上,采用全因子试验设计方法来构建响应面模型,以比吸能和初始峰值载荷为目标函数,运用多目标粒子群优化算法进行优化求解并获得最优解的Pareto集。研究结果表明:仿方竹结构薄壁管有较好的耐撞性和稳定性,壁厚0.892 mm、肋长2.995 mm为仿方竹结构的最优解,此时初始峰值载荷和比吸能分别为10 k N和7.936598 k J/kg。研究结果对薄壁管的结构设计和尺寸优化具有重要意义。
