针对局部阴影导致光伏系统功率输出特性曲线呈现多峰值,最大功率追踪(Maximum power point tracking,MPPT)算法存在容易陷入局部极值、输出功率振荡等问题,将收敛快速、精度高和稳定性好的蒲公英优化(Dandelion optimization,DO)算法应...针对局部阴影导致光伏系统功率输出特性曲线呈现多峰值,最大功率追踪(Maximum power point tracking,MPPT)算法存在容易陷入局部极值、输出功率振荡等问题,将收敛快速、精度高和稳定性好的蒲公英优化(Dandelion optimization,DO)算法应用于光伏系统MPPT中。DO算法采用非线性减小的随机扰动因子α、向下凸振荡k值在MPPT初期阶段充分搜索全局区域,后期转向开发局部区域,确保输出功率稳定和精确收敛于最优功率;再结合不规则布朗运动逃避局部功率极值点,采用Levy飞行函数增强局部功率的搜索能力,最终算法收敛于全局最大功率。仿真结果表明,与灰狼算法(Grey wolf algorithm,GWO)、粒子群算法(Particle swarm algorithm,PSO)相比,DO算法具有追踪效率高、稳定性好、鲁棒性强等优点。展开更多
A one-dimensional BOD-DO coupling model for water quality simulation is presented, which adopts Streeter-Phelps equations and the theory of back-propagation artificial neural network. The water quality data of Yangtze...A one-dimensional BOD-DO coupling model for water quality simulation is presented, which adopts Streeter-Phelps equations and the theory of back-propagation artificial neural network. The water quality data of Yangtze River in the Chongqing region in the year of 1989 are divided into 5 groups and used in the learning and testing courses of this model. The result shows that such model is feasible for water quality simulation and is more accurate than traditional models.展开更多
文摘针对局部阴影导致光伏系统功率输出特性曲线呈现多峰值,最大功率追踪(Maximum power point tracking,MPPT)算法存在容易陷入局部极值、输出功率振荡等问题,将收敛快速、精度高和稳定性好的蒲公英优化(Dandelion optimization,DO)算法应用于光伏系统MPPT中。DO算法采用非线性减小的随机扰动因子α、向下凸振荡k值在MPPT初期阶段充分搜索全局区域,后期转向开发局部区域,确保输出功率稳定和精确收敛于最优功率;再结合不规则布朗运动逃避局部功率极值点,采用Levy飞行函数增强局部功率的搜索能力,最终算法收敛于全局最大功率。仿真结果表明,与灰狼算法(Grey wolf algorithm,GWO)、粒子群算法(Particle swarm algorithm,PSO)相比,DO算法具有追踪效率高、稳定性好、鲁棒性强等优点。
基金Funded by the National Natural Science Foundation of China (No.59838300 No.59778021)
文摘A one-dimensional BOD-DO coupling model for water quality simulation is presented, which adopts Streeter-Phelps equations and the theory of back-propagation artificial neural network. The water quality data of Yangtze River in the Chongqing region in the year of 1989 are divided into 5 groups and used in the learning and testing courses of this model. The result shows that such model is feasible for water quality simulation and is more accurate than traditional models.
