Maximum Power Point Tracking (MPPT) is an important process in Photovoltaic (PV) systems because of the need to extract maximum power from PV panels used in these systems. Without the ability to track and have PV pane...Maximum Power Point Tracking (MPPT) is an important process in Photovoltaic (PV) systems because of the need to extract maximum power from PV panels used in these systems. Without the ability to track and have PV panels operate at its maximum power point (MPP) entails power losses;resulting in high cost since more panels will be required to provide specified energy needs. To achieve high efficiency and low cost, MPPT has therefore become an imperative in PV systems. In this study, an MPP tracker is modeled using the IC algorithm and its behavior under rapidly changing environmental conditions of temperature and irradiation levels is investigated. This algorithm, based on knowledge of the variation of the conductance of PV cells and the operating point with respect to the voltage and current of the panel calculates the slope of the power characteristics to determine the MPP as the peak of the curve. A simple circuit model of the DC-DC boost converter connected to a PV panel is used in the simulation;and the output of the boost converter is fed through a 3-phase inverter to an electricity grid. The model was simulated and tested using MATLAB/Simulink. Simulation results show the effectiveness of the IC algorithm for tracking the MPP in PV systems operating under rapidly changing temperatures and irradiations with a settling time of 2 seconds.展开更多
The dynamic shear modulus (DSM) is the most basic soil parameter in earthquake or other dynamic loading conditions and can be obtained through testing in the field or in the laboratory. The effect of consolidation rat...The dynamic shear modulus (DSM) is the most basic soil parameter in earthquake or other dynamic loading conditions and can be obtained through testing in the field or in the laboratory. The effect of consolidation ratios on the maximum DSM for two types of sand is investigated by using resonant column tests. And, an increment formula to obtain the maximum DSM for cases of consolidation ratio κc>1 is presented. The results indicate that the maximum DSM rises rapidly when κc is near 1 and then slows down, which means that the power function of the consolidation ratio increment κc-1 can be used to describe the variation of the maximum DSM due to κc>1. The results also indicate that the increase in the maximum DSM due to κc>1 is significantly larger than that predicted by Hardin and Black's formula.展开更多
光伏发电阵列板在局部遮阴下会产生多个功率峰值,传统算法难以准确快速追踪光伏最大功率点(maximum power point,MPP),该文提出一种基于莱维飞行灰狼算法(Levy grey wolf optimization,LGWO)与电导增量法(incremental conductance,INC)...光伏发电阵列板在局部遮阴下会产生多个功率峰值,传统算法难以准确快速追踪光伏最大功率点(maximum power point,MPP),该文提出一种基于莱维飞行灰狼算法(Levy grey wolf optimization,LGWO)与电导增量法(incremental conductance,INC)结合的复合算法追寻MPP,莱维飞行帮助灰狼算法跳出局部最优,搜寻MPP附近时,切换电导增量算法减少系统振荡,在静态与动态局部遮阴下通过Simulink进行光伏并网仿真验证。研究结果显示,所提复合算法收敛效果快速精确,并且符合并网谐波(total harmonic distortion,THD)含量要求,可保证系统的稳定运行。展开更多
实际工程中,光伏阵列在随机变化的环境中会出现局部遮光的情况,从而导致光伏阵列的功率-电压特性曲线会呈现多峰值状态,传统的最大功率点跟踪(maximum power point tracking, MPPT)算法易陷入局部最优解,追踪速度和精准度无法得到满足...实际工程中,光伏阵列在随机变化的环境中会出现局部遮光的情况,从而导致光伏阵列的功率-电压特性曲线会呈现多峰值状态,传统的最大功率点跟踪(maximum power point tracking, MPPT)算法易陷入局部最优解,追踪速度和精准度无法得到满足。针对这一问题,提出一种基于布谷鸟搜索算法(cuckoo search algorithm, CS)和电导增量法(conductivity increment method, CI)结合的光伏MPPT算法,在算法前期利用布谷鸟搜索算法将大步长和小步长交替使用使得全局搜索能力增强,找到全局最大功率点所处区域附近;在后期,采用步长小、控制精度高的CI进行局部寻优,快速准确地锁定到最大功率点。在MATLAB/Simulink中搭建仿真模型,并与原始布谷鸟搜索算法和粒子群优化(particle swam optimization, PSO)算法进行比较。仿真结果表明,将CS与CI结合的算法使得收敛速度更快,精度更高,稳定状态时功率曲线的波动更小。展开更多
实现光伏阵列最大功率点跟踪(Maximum power point tracking, MPPT)的传统算法已经较为成熟,但是在局部阴影出现后会发生寻优失效,难以实现全局最大功率跟踪(Global maximum power tracking, GMPPT)。为解决该问题,研究人员提出将粒子群...实现光伏阵列最大功率点跟踪(Maximum power point tracking, MPPT)的传统算法已经较为成熟,但是在局部阴影出现后会发生寻优失效,难以实现全局最大功率跟踪(Global maximum power tracking, GMPPT)。为解决该问题,研究人员提出将粒子群(Particle swarm optimization, PSO)等群搜索算法应用在MPPT控制过程中,虽然能够控制工作点稳定在全局最大功率点处,但由于该算法收敛能力依赖于核心参数,在应用过程中有一定概率会导致系统振荡。针对以上问题,在电导增量法(Incremental conductance, INC)的基础上提出跃变探索式电导增量法(Jump explore incremental conductance, JEINC),相较于传统电导增量法而言,具有较强的探索能力,能够在局部阴影下实现全局最大功率点跟踪控制,同时所提算法具有较好的收敛能力,在工作点位于最大功率点附近能够快速稳定。在三种光照环境下进行Matlab仿真,从稳定时间、暂态过程能量损耗率和振荡幅值三个方面验证了所提算法相较于电导增量法和粒子群算法的优越性。展开更多
针对传统的最大功率点追踪(Maximum Power Point Tracking,MPPT)算法陷入局部极值不能找到最大功率点(Maximum Power Point,MPP)以及传统的蝴蝶优化算法(Butterfly Optimization Algorithm,BOA)存在收敛速度慢和搜索震荡较大等问题,提...针对传统的最大功率点追踪(Maximum Power Point Tracking,MPPT)算法陷入局部极值不能找到最大功率点(Maximum Power Point,MPP)以及传统的蝴蝶优化算法(Butterfly Optimization Algorithm,BOA)存在收敛速度慢和搜索震荡较大等问题,提出一种改进的蝴蝶优化算法(Improved Butterfly Optimization Algorithm,IBOA)结合电导增量法(Conductance Increment Method,INC)的复合MPPT追踪方法。在IBOA中,引入自适应动态转换概率来平衡算法的全局与局部搜索,然后在全局搜索阶段引入Levy飞行策略,使蝴蝶个体广泛分布于搜索空间中,提高全局寻优能力;同时在局部搜索中设置新的寻优对象,并通过贪婪算法进行筛选保留,提高局部搜索的能力。当系统位于MPP附近时,利用INC局部搜索能力强的优点快速、准确地收敛到MPP并且稳定功率的输出。仿真结果表明,在静态和动态阴影下与BOA、PSO算法进行对比,所提算法具有更快的追踪速度、更高的追踪效率和更强的鲁棒性。展开更多
分布式光伏发电系统需要实时调整工作状态以适应环境变化,确保能量最大化输出。研究探索了最大功率点跟踪(Maximum Power Point Tracking,MPPT)的多种方法,包括扰动观测法、电导增量法、模糊逻辑控制法以及粒子群优化方法。这些方法通...分布式光伏发电系统需要实时调整工作状态以适应环境变化,确保能量最大化输出。研究探索了最大功率点跟踪(Maximum Power Point Tracking,MPPT)的多种方法,包括扰动观测法、电导增量法、模糊逻辑控制法以及粒子群优化方法。这些方法通过精细调节光伏系统的工作点,优化功率输出。各方法在响应速度、精度及稳定性方面表现各异,提供了有效的系统设计和实施指导。展开更多
文摘Maximum Power Point Tracking (MPPT) is an important process in Photovoltaic (PV) systems because of the need to extract maximum power from PV panels used in these systems. Without the ability to track and have PV panels operate at its maximum power point (MPP) entails power losses;resulting in high cost since more panels will be required to provide specified energy needs. To achieve high efficiency and low cost, MPPT has therefore become an imperative in PV systems. In this study, an MPP tracker is modeled using the IC algorithm and its behavior under rapidly changing environmental conditions of temperature and irradiation levels is investigated. This algorithm, based on knowledge of the variation of the conductance of PV cells and the operating point with respect to the voltage and current of the panel calculates the slope of the power characteristics to determine the MPP as the peak of the curve. A simple circuit model of the DC-DC boost converter connected to a PV panel is used in the simulation;and the output of the boost converter is fed through a 3-phase inverter to an electricity grid. The model was simulated and tested using MATLAB/Simulink. Simulation results show the effectiveness of the IC algorithm for tracking the MPP in PV systems operating under rapidly changing temperatures and irradiations with a settling time of 2 seconds.
基金The Science and Technology Ministration of China and the Earthquake Science Foundation of China (Grand No. 102033)
文摘The dynamic shear modulus (DSM) is the most basic soil parameter in earthquake or other dynamic loading conditions and can be obtained through testing in the field or in the laboratory. The effect of consolidation ratios on the maximum DSM for two types of sand is investigated by using resonant column tests. And, an increment formula to obtain the maximum DSM for cases of consolidation ratio κc>1 is presented. The results indicate that the maximum DSM rises rapidly when κc is near 1 and then slows down, which means that the power function of the consolidation ratio increment κc-1 can be used to describe the variation of the maximum DSM due to κc>1. The results also indicate that the increase in the maximum DSM due to κc>1 is significantly larger than that predicted by Hardin and Black's formula.
文摘光伏发电阵列板在局部遮阴下会产生多个功率峰值,传统算法难以准确快速追踪光伏最大功率点(maximum power point,MPP),该文提出一种基于莱维飞行灰狼算法(Levy grey wolf optimization,LGWO)与电导增量法(incremental conductance,INC)结合的复合算法追寻MPP,莱维飞行帮助灰狼算法跳出局部最优,搜寻MPP附近时,切换电导增量算法减少系统振荡,在静态与动态局部遮阴下通过Simulink进行光伏并网仿真验证。研究结果显示,所提复合算法收敛效果快速精确,并且符合并网谐波(total harmonic distortion,THD)含量要求,可保证系统的稳定运行。
文摘实现光伏阵列最大功率点跟踪(Maximum power point tracking, MPPT)的传统算法已经较为成熟,但是在局部阴影出现后会发生寻优失效,难以实现全局最大功率跟踪(Global maximum power tracking, GMPPT)。为解决该问题,研究人员提出将粒子群(Particle swarm optimization, PSO)等群搜索算法应用在MPPT控制过程中,虽然能够控制工作点稳定在全局最大功率点处,但由于该算法收敛能力依赖于核心参数,在应用过程中有一定概率会导致系统振荡。针对以上问题,在电导增量法(Incremental conductance, INC)的基础上提出跃变探索式电导增量法(Jump explore incremental conductance, JEINC),相较于传统电导增量法而言,具有较强的探索能力,能够在局部阴影下实现全局最大功率点跟踪控制,同时所提算法具有较好的收敛能力,在工作点位于最大功率点附近能够快速稳定。在三种光照环境下进行Matlab仿真,从稳定时间、暂态过程能量损耗率和振荡幅值三个方面验证了所提算法相较于电导增量法和粒子群算法的优越性。
文摘针对传统的最大功率点追踪(Maximum Power Point Tracking,MPPT)算法陷入局部极值不能找到最大功率点(Maximum Power Point,MPP)以及传统的蝴蝶优化算法(Butterfly Optimization Algorithm,BOA)存在收敛速度慢和搜索震荡较大等问题,提出一种改进的蝴蝶优化算法(Improved Butterfly Optimization Algorithm,IBOA)结合电导增量法(Conductance Increment Method,INC)的复合MPPT追踪方法。在IBOA中,引入自适应动态转换概率来平衡算法的全局与局部搜索,然后在全局搜索阶段引入Levy飞行策略,使蝴蝶个体广泛分布于搜索空间中,提高全局寻优能力;同时在局部搜索中设置新的寻优对象,并通过贪婪算法进行筛选保留,提高局部搜索的能力。当系统位于MPP附近时,利用INC局部搜索能力强的优点快速、准确地收敛到MPP并且稳定功率的输出。仿真结果表明,在静态和动态阴影下与BOA、PSO算法进行对比,所提算法具有更快的追踪速度、更高的追踪效率和更强的鲁棒性。
文摘分布式光伏发电系统需要实时调整工作状态以适应环境变化,确保能量最大化输出。研究探索了最大功率点跟踪(Maximum Power Point Tracking,MPPT)的多种方法,包括扰动观测法、电导增量法、模糊逻辑控制法以及粒子群优化方法。这些方法通过精细调节光伏系统的工作点,优化功率输出。各方法在响应速度、精度及稳定性方面表现各异,提供了有效的系统设计和实施指导。
