Based on the characteristic of AC-excited variable speed constant frequency(VSCF)wind power generation,the vector control technique was applied in a doubly fed induction generator(DFIG).Maximum wind energy or maximum ...Based on the characteristic of AC-excited variable speed constant frequency(VSCF)wind power generation,the vector control technique was applied in a doubly fed induction generator(DFIG).Maximum wind energy or maximum output power point can be tracked by decoupling control of active power and reactive power.The research result shows that the net power of generation system delivered to grid in maximum wind energy tracking mode is not the most.We presented a novel maximum power point tracking(MPPT)control strategy by analyzing the DFIG mathematic model and power relations which delivered the maximum power to the grid.The maximum power point could be tracked automatically without measuring wind speed in the control strategy and the control was independent of optimal turbine power curve,which had excellent dynamic and static performances and robustness.Simulation and experimental results testify the accuracy and validity of the control strategy.展开更多
In the early development of the wind energy, the majority of the wind turbines have been operated at constant speed. Subsequently, the number of variable-speed wind turbines installed in wind farms has increased. In t...In the early development of the wind energy, the majority of the wind turbines have been operated at constant speed. Subsequently, the number of variable-speed wind turbines installed in wind farms has increased. In this paper, a comparative performance of fixed and variable speed wind generators with Pitch angle control has been presented. The first is based on a squirrel cage Induction Generator （IG） of 315 kW rated power, connected directly to the grid. The second incorporated a Permanent Magnet Synchronous Generator （PMSG） of 750 kW rated power. The performances of each studied wind generator are evaluated by simulation works and variable speed operation is highlighted as preferred mode of operation.展开更多
In this paper, we propose a H∞ robust observer-based control DC motor based on a photovoltaic pumping system. Maximum power point tracking is achieved via an algorithm using Perturb and Observe method, with array vol...In this paper, we propose a H∞ robust observer-based control DC motor based on a photovoltaic pumping system. Maximum power point tracking is achieved via an algorithm using Perturb and Observe method, with array voltage and current being used to generate the reference voltage which should be the PV panel’s operating voltage to get maximum available power. A Takagi-Sugeno (T-S) observer has been proposed and designed with non-measurable premise variables and the conditions of stability are given in terms of Linear Matrix Inequality (LMI). The simulation results show the effectiveness and robustness of the proposed method.展开更多
针对传统电导增量INC(incremental conductance)算法在跟踪最大功率点的过程中无法兼顾跟踪速度与稳态精度的问题,以及传统变步长算法在光照变化时容易发生误判的问题,提出了一种新型的自适应变步长INC算法。光照强度变化较大时,利用负...针对传统电导增量INC(incremental conductance)算法在跟踪最大功率点的过程中无法兼顾跟踪速度与稳态精度的问题,以及传统变步长算法在光照变化时容易发生误判的问题,提出了一种新型的自适应变步长INC算法。光照强度变化较大时,利用负载曲线与I-V特性曲线的工作原理,在暂稳态和非稳态下都可以根据最大功率点跟踪MPPT(maximum power point tracking)采样电流的变化,自适应调节跟踪速度;光照强度变化较小时,能够根据输出电压与功率的变化自适应减小步长,提高稳态精度。追踪速度是传统算法的9.3倍,是现有变步长算法的4.2倍,有效减少了光照强度变化带来的功率损失。展开更多
局部遮阴情况下光伏阵列的输出功率呈现多峰现象,导致传统MPPT控制算法失效,而基于元启发式算法的MPPT控制功率追踪速度慢,输出功率振荡大。针对上述问题,提出一种基于改进型灰狼优化算法(improved grey wolf optimization algorithm,IG...局部遮阴情况下光伏阵列的输出功率呈现多峰现象,导致传统MPPT控制算法失效,而基于元启发式算法的MPPT控制功率追踪速度慢,输出功率振荡大。针对上述问题,提出一种基于改进型灰狼优化算法(improved grey wolf optimization algorithm,IGWO)与改进型扰动观察法(improved perturbation and observation method,IP&O)相结合的光伏MPPT控制算法。IGWO采用非线性收敛因子调整策略提高算法适应性,并通过使用改进型莱维飞行与增强型醉汉漫步结合的搜索策略平衡全局搜索与局部寻优的关系。利用IGWO追踪至最大功率点附近,再与可调节扰动步长变化速率的IP&O结合实现最大功率的稳定输出。算法测试实验数据和仿真结果表明,所提出的MPPT控制算法具有快速的追踪速度和高输出精度,且在功率追踪过程中输出振荡小。展开更多
太阳能光伏阵列的输出功率随外界环境因素的变化而变化,为了能高效利用太阳能电池,需要进行光伏阵列的最大功率点跟踪(Maximum Power Point Tracking,简称MPPT)。扰动观察法以其简单有效而得到了广泛应用。提出了一种新颖的变步长扰动...太阳能光伏阵列的输出功率随外界环境因素的变化而变化,为了能高效利用太阳能电池,需要进行光伏阵列的最大功率点跟踪(Maximum Power Point Tracking,简称MPPT)。扰动观察法以其简单有效而得到了广泛应用。提出了一种新颖的变步长扰动观察法,对传统方法的动态特性进行优化。在Matlab/Simulink下进行了系统的建模与仿真,并进行了实验研究。结果表明,该方法能快速准确地跟踪外部环境变化,并能保证系统的稳定性。展开更多
光伏器件输出功率是外部环境、负载的非线性函数,为了充分发挥光伏器件的效能,最大功率点跟踪(Maximum Power Point Tracking,简称MPPT)控制应根据光伏器件的工作情况来调整占空比扰动量。现有变步长控制虽有较好的快速跟踪能力和稳态效...光伏器件输出功率是外部环境、负载的非线性函数,为了充分发挥光伏器件的效能,最大功率点跟踪(Maximum Power Point Tracking,简称MPPT)控制应根据光伏器件的工作情况来调整占空比扰动量。现有变步长控制虽有较好的快速跟踪能力和稳态效果,但实现复杂、通用性较差。在分析光伏器件输出功率与占空比变化关系的基础上,提出一种简单的变步长MPPT控制方法。仿真和实验结果表明,该方法能够使光伏发电系统快速跟踪外部环境变化,在最大功率点处的控制效果明显优于扰动观察法,且实现简单。展开更多
基金Funded by the National Natural Science Foundation of China(No.60974049)the Science and Technology Support Industrial Project of Jiangsu Province(No.BZ2008031,No.BE2008074,and No.BE2009090)+1 种基金the Nantong International Cooperative Project(No.W2009003)the Natural Science Foundation of Nantong University(No.08Z022 and No.08Z025).
文摘Based on the characteristic of AC-excited variable speed constant frequency(VSCF)wind power generation,the vector control technique was applied in a doubly fed induction generator(DFIG).Maximum wind energy or maximum output power point can be tracked by decoupling control of active power and reactive power.The research result shows that the net power of generation system delivered to grid in maximum wind energy tracking mode is not the most.We presented a novel maximum power point tracking(MPPT)control strategy by analyzing the DFIG mathematic model and power relations which delivered the maximum power to the grid.The maximum power point could be tracked automatically without measuring wind speed in the control strategy and the control was independent of optimal turbine power curve,which had excellent dynamic and static performances and robustness.Simulation and experimental results testify the accuracy and validity of the control strategy.
文摘In the early development of the wind energy, the majority of the wind turbines have been operated at constant speed. Subsequently, the number of variable-speed wind turbines installed in wind farms has increased. In this paper, a comparative performance of fixed and variable speed wind generators with Pitch angle control has been presented. The first is based on a squirrel cage Induction Generator （IG） of 315 kW rated power, connected directly to the grid. The second incorporated a Permanent Magnet Synchronous Generator （PMSG） of 750 kW rated power. The performances of each studied wind generator are evaluated by simulation works and variable speed operation is highlighted as preferred mode of operation.
文摘In this paper, we propose a H∞ robust observer-based control DC motor based on a photovoltaic pumping system. Maximum power point tracking is achieved via an algorithm using Perturb and Observe method, with array voltage and current being used to generate the reference voltage which should be the PV panel’s operating voltage to get maximum available power. A Takagi-Sugeno (T-S) observer has been proposed and designed with non-measurable premise variables and the conditions of stability are given in terms of Linear Matrix Inequality (LMI). The simulation results show the effectiveness and robustness of the proposed method.
文摘针对传统电导增量INC(incremental conductance)算法在跟踪最大功率点的过程中无法兼顾跟踪速度与稳态精度的问题,以及传统变步长算法在光照变化时容易发生误判的问题,提出了一种新型的自适应变步长INC算法。光照强度变化较大时,利用负载曲线与I-V特性曲线的工作原理,在暂稳态和非稳态下都可以根据最大功率点跟踪MPPT(maximum power point tracking)采样电流的变化,自适应调节跟踪速度;光照强度变化较小时,能够根据输出电压与功率的变化自适应减小步长,提高稳态精度。追踪速度是传统算法的9.3倍,是现有变步长算法的4.2倍,有效减少了光照强度变化带来的功率损失。
文摘局部遮阴情况下光伏阵列的输出功率呈现多峰现象,导致传统MPPT控制算法失效,而基于元启发式算法的MPPT控制功率追踪速度慢,输出功率振荡大。针对上述问题,提出一种基于改进型灰狼优化算法(improved grey wolf optimization algorithm,IGWO)与改进型扰动观察法(improved perturbation and observation method,IP&O)相结合的光伏MPPT控制算法。IGWO采用非线性收敛因子调整策略提高算法适应性,并通过使用改进型莱维飞行与增强型醉汉漫步结合的搜索策略平衡全局搜索与局部寻优的关系。利用IGWO追踪至最大功率点附近,再与可调节扰动步长变化速率的IP&O结合实现最大功率的稳定输出。算法测试实验数据和仿真结果表明,所提出的MPPT控制算法具有快速的追踪速度和高输出精度,且在功率追踪过程中输出振荡小。
文摘太阳能光伏阵列的输出功率随外界环境因素的变化而变化,为了能高效利用太阳能电池,需要进行光伏阵列的最大功率点跟踪(Maximum Power Point Tracking,简称MPPT)。扰动观察法以其简单有效而得到了广泛应用。提出了一种新颖的变步长扰动观察法,对传统方法的动态特性进行优化。在Matlab/Simulink下进行了系统的建模与仿真,并进行了实验研究。结果表明,该方法能快速准确地跟踪外部环境变化,并能保证系统的稳定性。
文摘光伏器件输出功率是外部环境、负载的非线性函数,为了充分发挥光伏器件的效能,最大功率点跟踪(Maximum Power Point Tracking,简称MPPT)控制应根据光伏器件的工作情况来调整占空比扰动量。现有变步长控制虽有较好的快速跟踪能力和稳态效果,但实现复杂、通用性较差。在分析光伏器件输出功率与占空比变化关系的基础上,提出一种简单的变步长MPPT控制方法。仿真和实验结果表明,该方法能够使光伏发电系统快速跟踪外部环境变化,在最大功率点处的控制效果明显优于扰动观察法,且实现简单。
