An on-board charger for efficiently charging multiple battery-operated electric vehicles(EVs)is introduced.It has evolved as a single-input dual-output(SIDO)integrated boost-single ended primary inductor converter(SEP...An on-board charger for efficiently charging multiple battery-operated electric vehicles(EVs)is introduced.It has evolved as a single-input dual-output(SIDO)integrated boost-single ended primary inductor converter(SEPIC)fly-back converter,offering cost-effectiveness,reliability,and higher efficiency compared to conventional chargers with equivalent specifications.The proposed system includes an additional regulated output terminal,in addition to an existing terminal for charging the EV battery of a 4-wheeler,which can be used to charge another EV battery,preferably a 2-wheeler.With the aid of control techniques,unity power factor operations are obtained during constant-voltage(CV)/constant-current(CC)charging for the grid-to-vehicle(G2V)operating mode.Using mathematical modelling analysis,the proposed system is developed in a Matlab/Simulink environment,and the results are validated in a real-time simulator using dSPACE-1104.The proposed system is employed for charging the batteries of two EVs with capacities of 400 V,40 A·h and 48 V,52 A·h for the 4-wheeler and 2-wheeler,respectively.Its performance is investigated under different operating modes and over a wide range of supply voltage variations to ensure safe and reliable operation of the charger.展开更多
This study investigates the effects of climate change factors and non-climate change factors on crop output in Nigeria. Empirical research approach was adopted with the use of secondary sources of time series annual d...This study investigates the effects of climate change factors and non-climate change factors on crop output in Nigeria. Empirical research approach was adopted with the use of secondary sources of time series annual data obtained from reputable sources for the period 1980-2013. Error Correction Mechanism was used for the analysis. It was found that in the short run, only rainfall tested significantly positive to crop output among the climate change factors but there is evidence of significant effects of all climate change factors on crop output in the long-run. For example, temperature, carbon dioxide emission, carbon emission and rainfall were tested significantly to crop output. Furthermore, non-climate change factors like economically active population, gross capital formation, and land area equipped for irrigation were significantly positive to crop output. To forestall the effects of climate change on crop output, the study recommends that policy makers should formulate policies that will aid farmers towards adaptation practices in farming that can mitigate the effects of climate change. Furthermore, governments and other relevant agencies should also design programmes that can motivate the masses to increase their involvement in crop production.展开更多
提出了一种临界连续模式(CRM)单电感双输出(SIDO)Buck功率因数校正(PFC)变换器及其控制策略,并分析了其工作特性。通过对电感的分时复用控制,实现了2个输出支路的独立控制。在输入电压接近各输出支路电压情况下,控制器限制了开关管的最...提出了一种临界连续模式(CRM)单电感双输出(SIDO)Buck功率因数校正(PFC)变换器及其控制策略,并分析了其工作特性。通过对电感的分时复用控制,实现了2个输出支路的独立控制。在输入电压接近各输出支路电压情况下,控制器限制了开关管的最小关断时间,解决了工作于CRM时电感在输入电流过零点附近难以分时复用控制的问题,并抑制了电感在输入电流过零点附近的复用频率。相对于传统两级结构的多路输出PFC变换器,CRM SIDO Buck PFC变换器减少了控制器与电感的数量,降低了变换器的体积与成本,并提高了变换器的效率。实验结果验证了所提变换器高效率、高功率因数以及2个输出支路的高输出精度控制特性。展开更多
文摘An on-board charger for efficiently charging multiple battery-operated electric vehicles(EVs)is introduced.It has evolved as a single-input dual-output(SIDO)integrated boost-single ended primary inductor converter(SEPIC)fly-back converter,offering cost-effectiveness,reliability,and higher efficiency compared to conventional chargers with equivalent specifications.The proposed system includes an additional regulated output terminal,in addition to an existing terminal for charging the EV battery of a 4-wheeler,which can be used to charge another EV battery,preferably a 2-wheeler.With the aid of control techniques,unity power factor operations are obtained during constant-voltage(CV)/constant-current(CC)charging for the grid-to-vehicle(G2V)operating mode.Using mathematical modelling analysis,the proposed system is developed in a Matlab/Simulink environment,and the results are validated in a real-time simulator using dSPACE-1104.The proposed system is employed for charging the batteries of two EVs with capacities of 400 V,40 A·h and 48 V,52 A·h for the 4-wheeler and 2-wheeler,respectively.Its performance is investigated under different operating modes and over a wide range of supply voltage variations to ensure safe and reliable operation of the charger.
文摘This study investigates the effects of climate change factors and non-climate change factors on crop output in Nigeria. Empirical research approach was adopted with the use of secondary sources of time series annual data obtained from reputable sources for the period 1980-2013. Error Correction Mechanism was used for the analysis. It was found that in the short run, only rainfall tested significantly positive to crop output among the climate change factors but there is evidence of significant effects of all climate change factors on crop output in the long-run. For example, temperature, carbon dioxide emission, carbon emission and rainfall were tested significantly to crop output. Furthermore, non-climate change factors like economically active population, gross capital formation, and land area equipped for irrigation were significantly positive to crop output. To forestall the effects of climate change on crop output, the study recommends that policy makers should formulate policies that will aid farmers towards adaptation practices in farming that can mitigate the effects of climate change. Furthermore, governments and other relevant agencies should also design programmes that can motivate the masses to increase their involvement in crop production.
文摘提出了一种临界连续模式(CRM)单电感双输出(SIDO)Buck功率因数校正(PFC)变换器及其控制策略,并分析了其工作特性。通过对电感的分时复用控制,实现了2个输出支路的独立控制。在输入电压接近各输出支路电压情况下,控制器限制了开关管的最小关断时间,解决了工作于CRM时电感在输入电流过零点附近难以分时复用控制的问题,并抑制了电感在输入电流过零点附近的复用频率。相对于传统两级结构的多路输出PFC变换器,CRM SIDO Buck PFC变换器减少了控制器与电感的数量,降低了变换器的体积与成本,并提高了变换器的效率。实验结果验证了所提变换器高效率、高功率因数以及2个输出支路的高输出精度控制特性。
