光伏出力的随机性和负荷用电的波动性对微电网的优化调度影响显著,为此提出了预测-调节-决策一体化的策略框架。基于高斯过程回归(Gaussian process regression,GPR)将光伏出力和负荷用电典型日历史数据自适应生成的置信区间与鲁棒优化...光伏出力的随机性和负荷用电的波动性对微电网的优化调度影响显著,为此提出了预测-调节-决策一体化的策略框架。基于高斯过程回归(Gaussian process regression,GPR)将光伏出力和负荷用电典型日历史数据自适应生成的置信区间与鲁棒优化中不确定集的构建相结合,建立了基于区间概率不确定集的自适应鲁棒优化调度模型。首先,通过GPR生成自适应鲁棒优化调度模型中不确定集的固定项,然后调节决策环节所考虑的风险水平以确定不确定集中的波动项,进而确定衡量不同调度保守度下的不确定集边界;接着采用预测区间质量评测指标来考核各个不确定集所对应的区间优劣。最后,通过改进的IEEE-37节点微电网系统验证了所提模型在有效抵御光伏出力和负荷用电波动的同时保持较低的运行成本。展开更多
Bedding structural planes significantly influence the mechanical properties and stability of engineering rock masses.This study conducts uniaxial compression tests on layered sandstone with various bedding angles(0...Bedding structural planes significantly influence the mechanical properties and stability of engineering rock masses.This study conducts uniaxial compression tests on layered sandstone with various bedding angles(0°,15°,30°,45°,60°,75°and 90°)to explore the impact of bedding angle on the deformational mechanical response,failure mode,and damage evolution processes of rocks.It develops a damage model based on the Logistic equation derived from the modulus’s degradation considering the combined effect of the sandstone bedding dip angle and load.This model is employed to study the damage accumulation state and its evolution within the layered rock mass.This research also introduces a piecewise constitutive model that considers the initial compaction characteristics to simulate the whole deformation process of layered sandstone under uniaxial compression.The results revealed that as the bedding angle increases from 0°to 90°,the uniaxial compressive strength and elastic modulus of layered sandstone significantly decrease,slightly increase,and then decline again.The corresponding failure modes transition from splitting tensile failure to slipping shear failure and back to splitting tensile failure.As indicated by the modulus’s degradation,the damage characteristics can be categorized into four stages:initial no damage,damage initiation,damage acceleration,and damage deceleration termination.The theoretical damage model based on the Logistic equation effectively simulates and predicts the entire damage evolution process.Moreover,the theoretical constitutive model curves closely align with the actual stress−strain curves of layered sandstone under uniaxial compression.The introduced constitutive model is concise,with fewer parameters,a straightforward parameter determination process,and a clear physical interpretation.This study offers valuable insights into the theory of layered rock mechanics and holds implications for ensuring the safety of rock engineering.展开更多
Rockburst is one of the major disasters in deep underground rock mechanics and engineering.The precursors of rockbursts play important roles in rockburst prediction.Strainburst experiments were performed under double-...Rockburst is one of the major disasters in deep underground rock mechanics and engineering.The precursors of rockbursts play important roles in rockburst prediction.Strainburst experiments were performed under double-face unloading on sandstone with horizontal bedding planes using an independently designed rockburst testing facility.P-wave propagation time during the tests was automatically recorded by the acoustic emission apparatus.The P-wave velocities were calculated in both two directions to analyze their patterns.To find a characteristic precursor for rockburst,the dynamic evolution of rock anisotropy during the rockburst test is quantified by the anisotropic coefficient k,defined as the ratio of the two P-wave velocities in the directions vertical to and parallel to the bedding planes.The results show that rockburst occurs on the two free surfaces asynchronously.The rockburst failure occurs in the following order:crack generation,rock peeling,particle ejection,and rock fracture.In the process of rockburst under double-face unloading,the potential evolution characteristics of anisotropy can be generalized as anisotropy-isotropy-anisotropy.The suddenly unloading induces damage in the rock and presents anisotropic coefficient k steeply increasing departing from one,i.e.,isotropy.The rocks with horizontal bedding planes will reach the isotropic state before rockburst,which could be considered as a characteristic precursor of this kind of rockburst.展开更多
文摘光伏出力的随机性和负荷用电的波动性对微电网的优化调度影响显著,为此提出了预测-调节-决策一体化的策略框架。基于高斯过程回归(Gaussian process regression,GPR)将光伏出力和负荷用电典型日历史数据自适应生成的置信区间与鲁棒优化中不确定集的构建相结合,建立了基于区间概率不确定集的自适应鲁棒优化调度模型。首先,通过GPR生成自适应鲁棒优化调度模型中不确定集的固定项,然后调节决策环节所考虑的风险水平以确定不确定集中的波动项,进而确定衡量不同调度保守度下的不确定集边界;接着采用预测区间质量评测指标来考核各个不确定集所对应的区间优劣。最后,通过改进的IEEE-37节点微电网系统验证了所提模型在有效抵御光伏出力和负荷用电波动的同时保持较低的运行成本。
基金Projects(52074299,41941018)supported by the National Natural Science Foundation of ChinaProject(2023JCCXSB02)supported by the Fundamental Research Funds for the Central Universities,China。
文摘Bedding structural planes significantly influence the mechanical properties and stability of engineering rock masses.This study conducts uniaxial compression tests on layered sandstone with various bedding angles(0°,15°,30°,45°,60°,75°and 90°)to explore the impact of bedding angle on the deformational mechanical response,failure mode,and damage evolution processes of rocks.It develops a damage model based on the Logistic equation derived from the modulus’s degradation considering the combined effect of the sandstone bedding dip angle and load.This model is employed to study the damage accumulation state and its evolution within the layered rock mass.This research also introduces a piecewise constitutive model that considers the initial compaction characteristics to simulate the whole deformation process of layered sandstone under uniaxial compression.The results revealed that as the bedding angle increases from 0°to 90°,the uniaxial compressive strength and elastic modulus of layered sandstone significantly decrease,slightly increase,and then decline again.The corresponding failure modes transition from splitting tensile failure to slipping shear failure and back to splitting tensile failure.As indicated by the modulus’s degradation,the damage characteristics can be categorized into four stages:initial no damage,damage initiation,damage acceleration,and damage deceleration termination.The theoretical damage model based on the Logistic equation effectively simulates and predicts the entire damage evolution process.Moreover,the theoretical constitutive model curves closely align with the actual stress−strain curves of layered sandstone under uniaxial compression.The introduced constitutive model is concise,with fewer parameters,a straightforward parameter determination process,and a clear physical interpretation.This study offers valuable insights into the theory of layered rock mechanics and holds implications for ensuring the safety of rock engineering.
基金Projects(41941018,51704298)supported by the National Natural Science Foundation of ChinaProject(2021JCCXSB03)supported by the Fundamental Research Funds for the Central Universities,China。
文摘Rockburst is one of the major disasters in deep underground rock mechanics and engineering.The precursors of rockbursts play important roles in rockburst prediction.Strainburst experiments were performed under double-face unloading on sandstone with horizontal bedding planes using an independently designed rockburst testing facility.P-wave propagation time during the tests was automatically recorded by the acoustic emission apparatus.The P-wave velocities were calculated in both two directions to analyze their patterns.To find a characteristic precursor for rockburst,the dynamic evolution of rock anisotropy during the rockburst test is quantified by the anisotropic coefficient k,defined as the ratio of the two P-wave velocities in the directions vertical to and parallel to the bedding planes.The results show that rockburst occurs on the two free surfaces asynchronously.The rockburst failure occurs in the following order:crack generation,rock peeling,particle ejection,and rock fracture.In the process of rockburst under double-face unloading,the potential evolution characteristics of anisotropy can be generalized as anisotropy-isotropy-anisotropy.The suddenly unloading induces damage in the rock and presents anisotropic coefficient k steeply increasing departing from one,i.e.,isotropy.The rocks with horizontal bedding planes will reach the isotropic state before rockburst,which could be considered as a characteristic precursor of this kind of rockburst.
