This preliminary study shows an innovative concept of searching for peat substitutes on basis of renewable raw materials considering the cultivation in extensive land use in Lower Saxony (Germany). Selecting suitable ...This preliminary study shows an innovative concept of searching for peat substitutes on basis of renewable raw materials considering the cultivation in extensive land use in Lower Saxony (Germany). Selecting suitable raw material plants against the background of ecological, social and economic issues followed by testing series including those materials should lead on to reliable results for a planned transition through a spatial analysis of potential areas for cultivation with a specific attention on wetlands. Thereby this short report illustrates the concept of the study as well as chosen interim results and it is to be understood as the first paper of a mini-series.展开更多
Nonlinear solution of reinforced concrete structures, particularly complete load-deflection response, requires tracing of the equilibrium path and proper treatment of the limit and bifurcation points. In this regard, ...Nonlinear solution of reinforced concrete structures, particularly complete load-deflection response, requires tracing of the equilibrium path and proper treatment of the limit and bifurcation points. In this regard, ordinary solution techniques lead to instability near the limit points and also have problems in case of snap-through and snap-back. Thus they fail to predict the complete load-displacement response. The arc-length method serves the purpose well in principle, received wide acceptance in finite element analysis, and has been used extensively. However modifications to the basic idea are vital to meet the particular needs of the analysis. This paper reviews some of the recent developments of the method in the last two decades, with particular emphasis on nonlinear finite element analysis of reinforced concrete structures.展开更多
Aiming at issues of life loss(LL)and overall energy efficiency(OEE)for battery energy storage system(BESS)in smoothing wind power fluctuations,a dynamic grouping control strategy of BESS for remaining useful life(RUL)...Aiming at issues of life loss(LL)and overall energy efficiency(OEE)for battery energy storage system(BESS)in smoothing wind power fluctuations,a dynamic grouping control strategy of BESS for remaining useful life(RUL)extension and OEE improvement is proposed.First,grid-connected power signals are obtained.Second,a model to optimize capacity allocation for three battery groups(BGs)in BESS is established considering LL and OEE,and it is solved by the designed improved beetle swarm antennae search algorithm.Then,a dynamic grouping method is proposed to dynamically adjust the grouping state of battery units(BUs)during operation to keep good sustainable dispatchability.Then,a double-layer power allocation approach coordinated with multi-principle is designed to reduce LL and improve OEE,and also keeps consistency of state of charge for BUs simultaneously.The upper layer achieves power allocation from BESS into the three BGs and power allocation method for each BG is determined.The lower layer,considering PCS efficiency under different working conditions,finishes power allocation from each BG into BUs inside it.Subsequently,an RUL evaluation model based on the swing door trend algorithm is built to shorten required calculation time.Finally,the proposed control strategy is simulated and results compared with other strategies demonstrate the proposed strategy acquires the longest RUL and highest OEE with smoothing wind power fluctuations effectively,which verifies its correctness and validity.展开更多
基金facilitated by the Ministry of Food,Agriculture and Consumer Protection of Lower Saxony(Germany).
文摘This preliminary study shows an innovative concept of searching for peat substitutes on basis of renewable raw materials considering the cultivation in extensive land use in Lower Saxony (Germany). Selecting suitable raw material plants against the background of ecological, social and economic issues followed by testing series including those materials should lead on to reliable results for a planned transition through a spatial analysis of potential areas for cultivation with a specific attention on wetlands. Thereby this short report illustrates the concept of the study as well as chosen interim results and it is to be understood as the first paper of a mini-series.
文摘Nonlinear solution of reinforced concrete structures, particularly complete load-deflection response, requires tracing of the equilibrium path and proper treatment of the limit and bifurcation points. In this regard, ordinary solution techniques lead to instability near the limit points and also have problems in case of snap-through and snap-back. Thus they fail to predict the complete load-displacement response. The arc-length method serves the purpose well in principle, received wide acceptance in finite element analysis, and has been used extensively. However modifications to the basic idea are vital to meet the particular needs of the analysis. This paper reviews some of the recent developments of the method in the last two decades, with particular emphasis on nonlinear finite element analysis of reinforced concrete structures.
基金supported by the National Key Research and Development Program of China(No.2018YFE0122200)the National Natural Science Foundation of China(No.52077078)the Fundamental Research Funds for the Central Universities(No.2020MS090).
文摘Aiming at issues of life loss(LL)and overall energy efficiency(OEE)for battery energy storage system(BESS)in smoothing wind power fluctuations,a dynamic grouping control strategy of BESS for remaining useful life(RUL)extension and OEE improvement is proposed.First,grid-connected power signals are obtained.Second,a model to optimize capacity allocation for three battery groups(BGs)in BESS is established considering LL and OEE,and it is solved by the designed improved beetle swarm antennae search algorithm.Then,a dynamic grouping method is proposed to dynamically adjust the grouping state of battery units(BUs)during operation to keep good sustainable dispatchability.Then,a double-layer power allocation approach coordinated with multi-principle is designed to reduce LL and improve OEE,and also keeps consistency of state of charge for BUs simultaneously.The upper layer achieves power allocation from BESS into the three BGs and power allocation method for each BG is determined.The lower layer,considering PCS efficiency under different working conditions,finishes power allocation from each BG into BUs inside it.Subsequently,an RUL evaluation model based on the swing door trend algorithm is built to shorten required calculation time.Finally,the proposed control strategy is simulated and results compared with other strategies demonstrate the proposed strategy acquires the longest RUL and highest OEE with smoothing wind power fluctuations effectively,which verifies its correctness and validity.
