Constant envelope with a fractional Fourier transformorthogonal frequency division multiplexing(CE-FrFT-OFDM)is a special case of a constant envelope OFDM(CE-OFDM),both being energy efficient wireless communication te...Constant envelope with a fractional Fourier transformorthogonal frequency division multiplexing(CE-FrFT-OFDM)is a special case of a constant envelope OFDM(CE-OFDM),both being energy efficient wireless communication techniques with a 0 dB peak to average power ratio(PAPR).However,with the proper selection of fractional order,the first technique has a high bit error rate(BER)performance in the frequency-time selective channels.This paper performs further analysis of CE-FrFT-OFDM by examining its spectral efficiency(SE)and energy efficiency(EE)and compare to the famous OFDM and FrFT-OFDM techniques.Analytical and comprehensive simulations conducted show that,the CE-FrFT-OFDM has five times the EE of OFDM and FrFT-OFDM systems with a slightly less SE.Increasing CE-FrFT-OFDM’s transmission power by increasing its amplitude to 1.7 increases its SE to match that of the OFDM and FrFT-OFDM systems while slightly reducing its EE by 20%to be four times that of OFDM and FrFTOFDM systems.OFDM and FrFT-OFDM’s amplitude fluctuations cause rapid changing output back-off(OBO)power requirements and further reduce power amplifier(PA)efficiency while CE-FrFTOFDM stable operational linear range makes it a better candidate and outperforms the other techniques when their OBO exceeds 1.7.Higher EE and low BER in time-frequency selective channel are attracting features for CE-FrFT-OFDM deployment in mobile devices.展开更多
Carrying out green energy transformation,implementing clean energy power replacement and supply,and developing a new power system are some primary driving forces needed to fulfill China’s carbon-peak and carbon-neutr...Carrying out green energy transformation,implementing clean energy power replacement and supply,and developing a new power system are some primary driving forces needed to fulfill China’s carbon-peak and carbon-neutral strategic goals.The construction of new power systems in China’s provinces and cities is developing rapidly,and the lack of a typical model promotes the application.The new power system path design should be based on the actual development of the power grid in different regions,energy use characteristics,and other actual needs to carry out the differentiated path design.In this context,this study analyzes the characteristics of the new domestic power system based on the policy background of the new domestic power system,constructs a new model for power system development stage identification,and proposes the overall design of the new power system development path from the power supply,transmission and distribution,and load sides.It also uses the Hebei South Network as an example to explore the development stage of the Hebei South Grid based on actual development needs.Finally,this study designs a novel power system development path for the entire supply and demand chain for the Hebei South Grid to propose ideas for constructing a new power system in China and to help green energy transformation.展开更多
China Longyuan Power was listed on the main board of Hong Kong Stock Exchange in 2009.The successful listing proved the correctness and timeliness of China Guodian's strategy of "leading enterprises to transf...China Longyuan Power was listed on the main board of Hong Kong Stock Exchange in 2009.The successful listing proved the correctness and timeliness of China Guodian's strategy of "leading enterprises to transformation by exploring new energy resources energetically."展开更多
探讨了基于《DL/T985-2022配电变压器能效技术经济评价导则》(Guide for determining energy efficiency for distribution transformers)的变压器经济选型问题,分析了在两部制电价条件下,变压器容量选择对综合能效费用的影响。通过建...探讨了基于《DL/T985-2022配电变压器能效技术经济评价导则》(Guide for determining energy efficiency for distribution transformers)的变压器经济选型问题,分析了在两部制电价条件下,变压器容量选择对综合能效费用的影响。通过建立计算模型,选取了变压器容量、空载损耗、负载损耗、变压器价格、贴现率、电价等参数,对变压器的经济选型进行了全面分析。研究结果表明,变压器容量是影响综合能效费用的主要因素,其影响权重远大于其他因素。提出了简化模型和设计建议,以优化变压器容量选型,提高负载率,减少容量电费。展开更多
文摘Constant envelope with a fractional Fourier transformorthogonal frequency division multiplexing(CE-FrFT-OFDM)is a special case of a constant envelope OFDM(CE-OFDM),both being energy efficient wireless communication techniques with a 0 dB peak to average power ratio(PAPR).However,with the proper selection of fractional order,the first technique has a high bit error rate(BER)performance in the frequency-time selective channels.This paper performs further analysis of CE-FrFT-OFDM by examining its spectral efficiency(SE)and energy efficiency(EE)and compare to the famous OFDM and FrFT-OFDM techniques.Analytical and comprehensive simulations conducted show that,the CE-FrFT-OFDM has five times the EE of OFDM and FrFT-OFDM systems with a slightly less SE.Increasing CE-FrFT-OFDM’s transmission power by increasing its amplitude to 1.7 increases its SE to match that of the OFDM and FrFT-OFDM systems while slightly reducing its EE by 20%to be four times that of OFDM and FrFTOFDM systems.OFDM and FrFT-OFDM’s amplitude fluctuations cause rapid changing output back-off(OBO)power requirements and further reduce power amplifier(PA)efficiency while CE-FrFTOFDM stable operational linear range makes it a better candidate and outperforms the other techniques when their OBO exceeds 1.7.Higher EE and low BER in time-frequency selective channel are attracting features for CE-FrFT-OFDM deployment in mobile devices.
基金funded by the State Grid Hebei Electric Power Co.,Ltd projectthe National Natural Science Foundation of China’s major project,“Research on the Construction of China’s Economic Transformation Mode for Carbon Neutrality(72140001)This study is titled“Research on Novel Power System Development Path”。
文摘Carrying out green energy transformation,implementing clean energy power replacement and supply,and developing a new power system are some primary driving forces needed to fulfill China’s carbon-peak and carbon-neutral strategic goals.The construction of new power systems in China’s provinces and cities is developing rapidly,and the lack of a typical model promotes the application.The new power system path design should be based on the actual development of the power grid in different regions,energy use characteristics,and other actual needs to carry out the differentiated path design.In this context,this study analyzes the characteristics of the new domestic power system based on the policy background of the new domestic power system,constructs a new model for power system development stage identification,and proposes the overall design of the new power system development path from the power supply,transmission and distribution,and load sides.It also uses the Hebei South Network as an example to explore the development stage of the Hebei South Grid based on actual development needs.Finally,this study designs a novel power system development path for the entire supply and demand chain for the Hebei South Grid to propose ideas for constructing a new power system in China and to help green energy transformation.
文摘China Longyuan Power was listed on the main board of Hong Kong Stock Exchange in 2009.The successful listing proved the correctness and timeliness of China Guodian's strategy of "leading enterprises to transformation by exploring new energy resources energetically."
文摘探讨了基于《DL/T985-2022配电变压器能效技术经济评价导则》(Guide for determining energy efficiency for distribution transformers)的变压器经济选型问题,分析了在两部制电价条件下,变压器容量选择对综合能效费用的影响。通过建立计算模型,选取了变压器容量、空载损耗、负载损耗、变压器价格、贴现率、电价等参数,对变压器的经济选型进行了全面分析。研究结果表明,变压器容量是影响综合能效费用的主要因素,其影响权重远大于其他因素。提出了简化模型和设计建议,以优化变压器容量选型,提高负载率,减少容量电费。
