The rate of fire spread is a key indicator for assessing forest fire risk and developing fire management plans.The Rothermel model is the most widely used fire spread model,established through laboratory experiments o...The rate of fire spread is a key indicator for assessing forest fire risk and developing fire management plans.The Rothermel model is the most widely used fire spread model,established through laboratory experiments on homogeneous fuels but has not been validated for conifer-deciduous mixed fuel.In this study,Pinus koraiensis and Quercus mongolica litter was used in a laboratory burning experiment to simulate surface fire spread in the field.The effects of fuel moisture content,mixed fuel ratio and slope on spread rate were analyzed.The optimum packing ratio,moisture-damping coefficient and slope parameters in the Rothermel model were modified using the measured spread rate which was positively correlated with slope and negatively with fuel moisture content.As the Q.mongolica load increased,the spread rate increased and was highest at a fuel ratio of 4:6.The model with modified optimal packing ratio and slope parameters has a significantly lower spread rate prediction error than the unmodified model.The spread rate prediction accuracy was significantly improved after modifying the model parameters based on spread rates from laboratory burning simulations.展开更多
Load frequency control(LFC)is a critical function to balance the power consumption and generation.Thegrid frequency is a crucial indicator for maintaining balance.However,the widely used information and communication ...Load frequency control(LFC)is a critical function to balance the power consumption and generation.Thegrid frequency is a crucial indicator for maintaining balance.However,the widely used information and communication infrastructure for LFC increases the risk of being attacked by malicious actors.The dynamic load altering attack(DLAA)is a typical attack that can destabilize the power system,causing the grid frequency to deviate fromits nominal value.Therefore,in this paper,we mathematically analyze the impact of DLAA on the stability of the grid frequency and propose the network parameter regulation(NPR)to mitigate the impact.To begin with,the dynamic LFC model is constructed by highlighting the importance of the network parameter.Then,we model the DLAA and analyze its impact on LFC using the theory of second-order dynamic systems.Finally,we model the NPR and prove its effect in mitigating the DLAA.Besides,we construct a least-effort NPR considering its infrastructure cost and aim to reduce the operation cost.Finally,we carry out extensive simulations to demonstrate the impact of the DLAA and evaluate the mitigation performance of NPR.The proposed cost-benefit NPR approach can not only mitigate the impact of DLAA with 100%and also save 41.18$/MWh in terms of the operation cost.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2020YFC1511603)the Fundamental Research Funds for the Central Universities(2572021BA04).
文摘The rate of fire spread is a key indicator for assessing forest fire risk and developing fire management plans.The Rothermel model is the most widely used fire spread model,established through laboratory experiments on homogeneous fuels but has not been validated for conifer-deciduous mixed fuel.In this study,Pinus koraiensis and Quercus mongolica litter was used in a laboratory burning experiment to simulate surface fire spread in the field.The effects of fuel moisture content,mixed fuel ratio and slope on spread rate were analyzed.The optimum packing ratio,moisture-damping coefficient and slope parameters in the Rothermel model were modified using the measured spread rate which was positively correlated with slope and negatively with fuel moisture content.As the Q.mongolica load increased,the spread rate increased and was highest at a fuel ratio of 4:6.The model with modified optimal packing ratio and slope parameters has a significantly lower spread rate prediction error than the unmodified model.The spread rate prediction accuracy was significantly improved after modifying the model parameters based on spread rates from laboratory burning simulations.
基金supported by the project Major Scientific and Technological Special Project of Guizhou Province([2024]014).
文摘Load frequency control(LFC)is a critical function to balance the power consumption and generation.Thegrid frequency is a crucial indicator for maintaining balance.However,the widely used information and communication infrastructure for LFC increases the risk of being attacked by malicious actors.The dynamic load altering attack(DLAA)is a typical attack that can destabilize the power system,causing the grid frequency to deviate fromits nominal value.Therefore,in this paper,we mathematically analyze the impact of DLAA on the stability of the grid frequency and propose the network parameter regulation(NPR)to mitigate the impact.To begin with,the dynamic LFC model is constructed by highlighting the importance of the network parameter.Then,we model the DLAA and analyze its impact on LFC using the theory of second-order dynamic systems.Finally,we model the NPR and prove its effect in mitigating the DLAA.Besides,we construct a least-effort NPR considering its infrastructure cost and aim to reduce the operation cost.Finally,we carry out extensive simulations to demonstrate the impact of the DLAA and evaluate the mitigation performance of NPR.The proposed cost-benefit NPR approach can not only mitigate the impact of DLAA with 100%and also save 41.18$/MWh in terms of the operation cost.
