A construction method for power system transient energy function is studied in the paper, which is simple and universal, and can unify the forms of some current en- ergy functions. A transient energy function includin...A construction method for power system transient energy function is studied in the paper, which is simple and universal, and can unify the forms of some current en- ergy functions. A transient energy function including the induction motor model is derived using the method. The unintegrable term is dealt with to get an approxi- mate energy function. Simulations in a 3-bus system and in the WSCC 4-generator system verify the validity of the proposed energy function. The function can be applied to direct transient stability analysis of multi-machine large power systems and provides a tool for analysis of the interaction between the generator angle stability and the load voltage stability.展开更多
The energy selective electron device works among electron reservoirs with different temperatures and chemical potentials.Electrons obey the Fermi-Dirac distribution,and with the help of resonant filters,a part of elec...The energy selective electron device works among electron reservoirs with different temperatures and chemical potentials.Electrons obey the Fermi-Dirac distribution,and with the help of resonant filters,a part of electrons with specific energy levels can tunnel among reservoirs and provide current to an external circuit.Herein,an irreversible three-terminal energy selective electron generator model is proposed.Using statistical mechanics and finite-time-thermodynamics,analytical expressions of power and efficiency are derived,and the optimal performance of the device is investigated.Results show that the central energy level difference of filters,the chemical potential difference of low-temperature reservoirs,the interval of mean-central-energy-level of filters and the mean-chemical-potential of low-temperature reservoirs can be optimized to maximize power and efficiency.On the basis of power and efficiency analyses,performance characteristics under different objective functions,including efficient power and ecological function,are discussed and the corresponding optimal performance regions are obtained.The relationship between the entropy generation rate and the efficiency is investigated,and it is shown that the minimum-entropy-generation-state does not coincide with the maximum-efficiency-state.展开更多
基金Supported by the Special Fund of the National Priority Basic Research of China (Grant No. 2004CB217904)the National Natural Science Foundation of China (Grant No. 50323002)
文摘A construction method for power system transient energy function is studied in the paper, which is simple and universal, and can unify the forms of some current en- ergy functions. A transient energy function including the induction motor model is derived using the method. The unintegrable term is dealt with to get an approxi- mate energy function. Simulations in a 3-bus system and in the WSCC 4-generator system verify the validity of the proposed energy function. The function can be applied to direct transient stability analysis of multi-machine large power systems and provides a tool for analysis of the interaction between the generator angle stability and the load voltage stability.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.51576207 and 51306206)the Hubei Province Natural Science Foundation of China(Grant No.2017CFB498).
文摘The energy selective electron device works among electron reservoirs with different temperatures and chemical potentials.Electrons obey the Fermi-Dirac distribution,and with the help of resonant filters,a part of electrons with specific energy levels can tunnel among reservoirs and provide current to an external circuit.Herein,an irreversible three-terminal energy selective electron generator model is proposed.Using statistical mechanics and finite-time-thermodynamics,analytical expressions of power and efficiency are derived,and the optimal performance of the device is investigated.Results show that the central energy level difference of filters,the chemical potential difference of low-temperature reservoirs,the interval of mean-central-energy-level of filters and the mean-chemical-potential of low-temperature reservoirs can be optimized to maximize power and efficiency.On the basis of power and efficiency analyses,performance characteristics under different objective functions,including efficient power and ecological function,are discussed and the corresponding optimal performance regions are obtained.The relationship between the entropy generation rate and the efficiency is investigated,and it is shown that the minimum-entropy-generation-state does not coincide with the maximum-efficiency-state.
