针对级联静止无功补偿器(STATCOM),提出一种基于现场可编程门阵列(FPGA)的高精度低成本实时仿真模型。为减小步长,提高仿真精度,提出一种改进开关函数法,将仿真模型分为非线性开关部分和线性电路部分,简化仿真模型,减少仿真计算量。通...针对级联静止无功补偿器(STATCOM),提出一种基于现场可编程门阵列(FPGA)的高精度低成本实时仿真模型。为减小步长,提高仿真精度,提出一种改进开关函数法,将仿真模型分为非线性开关部分和线性电路部分,简化仿真模型,减少仿真计算量。通过计算开关网络外电路电压及比较逻辑得到端口电压,实现H桥死区模式下的仿真,提高模型仿真的精度与实用性。通过实时检测H桥状态,确保二极管单向导电,保证仿真正确性。为了兼顾硬件资源消耗和仿真计算速度,在设计实现上采用串并行结合,以及深度流水线技术。每相12个级联H桥STATCOM实时仿真模型只需一片Cyclone IV EP4CE115即可实现,仿真步长可达到0.85?s。Simulink/PSIM仿真和实际功率电路实验结果均验证了所提出的实时仿真的有效性。展开更多
This study proposed a new and more flexible S-shaped rock damage evolution model from a phenomenological perspective based on an improved Logistic function to describe the characteristics of the rock strain softening ...This study proposed a new and more flexible S-shaped rock damage evolution model from a phenomenological perspective based on an improved Logistic function to describe the characteristics of the rock strain softening and damage process.Simultaneously,it established a constitutive model capable of describing the entire process of rock pre-peak compaction and post-peak strain softening deformation,considering the nonlinear effects of the initial compaction stage of rocks,combined with damage mechanics theory and effective medium theory.In addition,this research verified the rationality of the constructed damage constitutive model using results from uniaxial and conventional triaxial compression tests on Miluo granite,yellow sandstone,mudstone,and glutenite.The results indicate that based on the improved Logistic function,the theoretical damage model accurately describes the entire evolution of damage characteristics during rock compression deformation,from maintenance through gradual onset,accelerated development to deceleration and termination,in a simple and unified expression.At the same time,the constructed constitutive model can accurately simulate the stress-strain process of different rock types under uniaxial and conventional triaxial compression,and the theoretical model curve closely aligns with experimental data.Compared to existing constitutive models,the proposed model has significant advantages.The damage model parameters a,r and β have clear physical meanings and interact competitively,where the three parameters collectively determine the shape of the theoretical stress−strain curve.展开更多
文摘针对级联静止无功补偿器(STATCOM),提出一种基于现场可编程门阵列(FPGA)的高精度低成本实时仿真模型。为减小步长,提高仿真精度,提出一种改进开关函数法,将仿真模型分为非线性开关部分和线性电路部分,简化仿真模型,减少仿真计算量。通过计算开关网络外电路电压及比较逻辑得到端口电压,实现H桥死区模式下的仿真,提高模型仿真的精度与实用性。通过实时检测H桥状态,确保二极管单向导电,保证仿真正确性。为了兼顾硬件资源消耗和仿真计算速度,在设计实现上采用串并行结合,以及深度流水线技术。每相12个级联H桥STATCOM实时仿真模型只需一片Cyclone IV EP4CE115即可实现,仿真步长可达到0.85?s。Simulink/PSIM仿真和实际功率电路实验结果均验证了所提出的实时仿真的有效性。
基金Project(52074299)supported by the National Natural Science Foundation of ChinaProjects(2023JCCXSB02,BBJ2024083)supported by the Fundamental Research Funds for the Central Universities,China。
文摘This study proposed a new and more flexible S-shaped rock damage evolution model from a phenomenological perspective based on an improved Logistic function to describe the characteristics of the rock strain softening and damage process.Simultaneously,it established a constitutive model capable of describing the entire process of rock pre-peak compaction and post-peak strain softening deformation,considering the nonlinear effects of the initial compaction stage of rocks,combined with damage mechanics theory and effective medium theory.In addition,this research verified the rationality of the constructed damage constitutive model using results from uniaxial and conventional triaxial compression tests on Miluo granite,yellow sandstone,mudstone,and glutenite.The results indicate that based on the improved Logistic function,the theoretical damage model accurately describes the entire evolution of damage characteristics during rock compression deformation,from maintenance through gradual onset,accelerated development to deceleration and termination,in a simple and unified expression.At the same time,the constructed constitutive model can accurately simulate the stress-strain process of different rock types under uniaxial and conventional triaxial compression,and the theoretical model curve closely aligns with experimental data.Compared to existing constitutive models,the proposed model has significant advantages.The damage model parameters a,r and β have clear physical meanings and interact competitively,where the three parameters collectively determine the shape of the theoretical stress−strain curve.
