Load flow is an important tool used by power engineers for planning, to determine the best operation for a power system and exchange of power between utility companies. In order to have an efficient operating power sy...Load flow is an important tool used by power engineers for planning, to determine the best operation for a power system and exchange of power between utility companies. In order to have an efficient operating power system, it is necessary to determine which method is suitable and efficient for the system’s load flow analysis. A power flow analysis method may take a long time and therefore prevent achieving an accurate result to a power flow solution because of continuous changes in power demand and generations. This paper presents analysis of the load flow problem in power system planning studies. The numerical methods: Gauss-Seidel, Newton-Raphson and Fast Decoupled methods were compared for a power flow analysis solution. Simulation is carried out using Matlab for test cases of IEEE 9-Bus, IEEE 30-Bus and IEEE 57-Bus system. The simulation results were compared for number of iteration, computational time, tolerance value and convergence. The compared results show that Newton-Raphson is the most reliable method because it has the least number of iteration and converges faster.展开更多
在分析双馈感应发电机(doubly-fed induction generator,DFIG)运行特性和传统最大风能追踪控制(maximum power point tracking,MPPT)策略的基础上,给出一种基于约束因子限幅控制的DFIG有功功率平滑控制策略,提出功率输出限幅值可调的控...在分析双馈感应发电机(doubly-fed induction generator,DFIG)运行特性和传统最大风能追踪控制(maximum power point tracking,MPPT)策略的基础上,给出一种基于约束因子限幅控制的DFIG有功功率平滑控制策略,提出功率输出限幅值可调的控制思想,结合发电机转速控制和风力机变桨距控制来实现输出功率保持在任意给定值。给出了约束因子的表达式和取值规则。在Matlab/Simulink仿真平台上采用所提平滑控制策略,对一个9 MW风电场的有功功率输出特性进行研究,计算了2种控制策略下输出功率的平滑性能指标和方差值。实验结果表明,与传统最大风能追踪控制策略相比,所提出的平滑控制策略能显著减小发电机输出功率的波动,优化了系统的电能质量。展开更多
文摘Load flow is an important tool used by power engineers for planning, to determine the best operation for a power system and exchange of power between utility companies. In order to have an efficient operating power system, it is necessary to determine which method is suitable and efficient for the system’s load flow analysis. A power flow analysis method may take a long time and therefore prevent achieving an accurate result to a power flow solution because of continuous changes in power demand and generations. This paper presents analysis of the load flow problem in power system planning studies. The numerical methods: Gauss-Seidel, Newton-Raphson and Fast Decoupled methods were compared for a power flow analysis solution. Simulation is carried out using Matlab for test cases of IEEE 9-Bus, IEEE 30-Bus and IEEE 57-Bus system. The simulation results were compared for number of iteration, computational time, tolerance value and convergence. The compared results show that Newton-Raphson is the most reliable method because it has the least number of iteration and converges faster.
文摘在分析双馈感应发电机(doubly-fed induction generator,DFIG)运行特性和传统最大风能追踪控制(maximum power point tracking,MPPT)策略的基础上,给出一种基于约束因子限幅控制的DFIG有功功率平滑控制策略,提出功率输出限幅值可调的控制思想,结合发电机转速控制和风力机变桨距控制来实现输出功率保持在任意给定值。给出了约束因子的表达式和取值规则。在Matlab/Simulink仿真平台上采用所提平滑控制策略,对一个9 MW风电场的有功功率输出特性进行研究,计算了2种控制策略下输出功率的平滑性能指标和方差值。实验结果表明,与传统最大风能追踪控制策略相比,所提出的平滑控制策略能显著减小发电机输出功率的波动,优化了系统的电能质量。
