This paper introduces in detail the reactive power compensation technology and its characteristics, to reduce the loss of reactive power compensation technology 1N power distribution system and the electrical automati...This paper introduces in detail the reactive power compensation technology and its characteristics, to reduce the loss of reactive power compensation technology 1N power distribution system and the electrical automation, improve the utilization rate, and realize the control of the voltage amplitude in the system network, voltage stability of power distribution system, has carried on the system analysis to reduce failure of the harmonic current to the power supply system and other functions. And the paper in-depth study on the application of reactive power compensation technology in electrical automation from the reactive compensation technology, substation and distribution line reactive power compensation, power users of reactive power compensation and other aspects.展开更多
Under unbalanced source voltage supply, considerable output second harmonics and input low-order harmonics in 3-phase PWM current-source converters (PWM-CSC) are generated. This paper proposes a new deadbeat controlle...Under unbalanced source voltage supply, considerable output second harmonics and input low-order harmonics in 3-phase PWM current-source converters (PWM-CSC) are generated. This paper proposes a new deadbeat controller based on compensation for unbalanced source voltage and current. With the proposed scheme, the second harmonics of the output current are eliminated and low-order harmonics of the source current are reduced effectively. Simulation and experimental results con- firmed the feasibility of the proposed method.展开更多
Both winter DJF （December, January, February） months and DJF season means long-term data series of 50 regulated rivers discharges rates and the NAO indices were analyzed for different spans. This study is dictated ...Both winter DJF （December, January, February） months and DJF season means long-term data series of 50 regulated rivers discharges rates and the NAO indices were analyzed for different spans. This study is dictated for： （1） detecting the exclusive impacts of the positive phases of NAO indices on rivers discharges rates by estimating the Linear Correlation Coefficient; （2） modeling the interrelations between the discharges rates and NAO indices by estimating the Linear Regression Models, both for manifesting the impact of the positive phase of NAO index; （3） estimating the Linear Trend Coefficient in the discharge series, for manifesting the contribution of the positive phase of NAO index. Discharge rates are mainly influenced by the two mechanisms： the positive phase of NAO index and the environmental conditions in specific catchments, that is where, the positive phase of the NAO index manifest its impact on the related rivers discharges and its contribution in the related configured trends. The discharges fluctuations patterns show some increase in the discharges values have been occurred in regions around the Northern Baltic Proper as well as in Southern Finland and Sweden. The rivers such as Lagan, Nissan, Helgean, Venta, Pamu, Porvoonjoki, Lapuanjoki, Oulujoki, Kyronjoki, Wisla, Eurajoki, Odra, Lielupe, Gota alv, Motala strom, Nykopingsan, Vuoksi, Kalajoki and Simojoki haven not linear discharges changes registered depending on the specificity of the environmental conditions at the catchments areas for those rivers. The positive phase of NAO index has a linear relation with impacted river discharge.展开更多
This research describes an integrated multi-channel high accuracy current control LED （light emitting diode） driver with low dropout regulator implemented in a 0.35μm TSMC 2P4M CMOS process. With the new trend of b...This research describes an integrated multi-channel high accuracy current control LED （light emitting diode） driver with low dropout regulator implemented in a 0.35μm TSMC 2P4M CMOS process. With the new trend of backlighting applications for mobile electronics and portable devices requiring a smaller size, lower cost, lesser noise and accurate current control LED driver, it came up with the idea of integrating more than one design features within a single chip. The analysis of using a capacitor-less low dropout regulator to power the constant current source has been explored, with the implementation of wide range battery voltage of 3 V to 5 V. Possible load current variations were introduced and verified to output a fixed voltage of 2.8 V. A regulated cascode current mirror structure forms the multi-channel configuration string of LED＇s; the design ensures a current matching of less than 1% error and achieves a high accuracy current control of less than 1% error, regardless of the LED＇s forward voltage variation. Moreover, for high end portable device with multimedia applications, dimming frequency can be set to 10 MHz. In addition, a switching output is a better approach for managing LED＇s contrast and brightness adjustment as well as maximizing power consumption, ensuring longer life for driving string of LEDs.展开更多
This paper deals with the operation and performance of VSC （voltage source converter） based HVDC （high voltage direct current） interconnecting two extremely weak AC networks, the experience of Caprivilink project....This paper deals with the operation and performance of VSC （voltage source converter） based HVDC （high voltage direct current） interconnecting two extremely weak AC networks, the experience of Caprivilink project. It is shown in the paper that the HVDC converter automatically provides the supreme voltage and frequency stabilizing function when a critical situation is detected, no matter the disturbances appeared in sending end or receiving end AC networks. This supreme voltage and frequency stabilizing function makes it possible to avoid the blackout even if all the generators are tripped under an extra-ordinary worst contingency. By plots of recorded transients, the paper will show how the eventual blackouts are avoided.展开更多
DC regulated power has play a decisive role status in the modem enterprise production and family life. With the development of science and technology, all kinds of computer simulation technology is increasingly rising...DC regulated power has play a decisive role status in the modem enterprise production and family life. With the development of science and technology, all kinds of computer simulation technology is increasingly rising, the paper simulate and compare common DC regulated power with adjustable DC regulated power by Altium Designer software, intuitively demonstrates the stabilizing effect of the circuit, and introduces the characteristics of adjustable DC regulated power. Using AD13 software simulate and design DC stabilized power supply circuit, calculated the main parameters of the circuit, simulated and analyzed the circuit working simulation process and the working state of the circuit, it can visually verify the results of the theoretical analysis, and get relevant conclusions.展开更多
The study of peristaltic flow of a Carreau fluid in a non-uniform tube under the con- sideration of long wavelength is presented. The flow is investigated in a wave frame of reference moving with velocity of the wave ...The study of peristaltic flow of a Carreau fluid in a non-uniform tube under the con- sideration of long wavelength is presented. The flow is investigated in a wave frame of reference moving with velocity of the wave e. Numerical integration has been used to obtain the graphical results for pressure rise and frictional forces. The effects of various emerging parameters are investigated through graphs.展开更多
文摘This paper introduces in detail the reactive power compensation technology and its characteristics, to reduce the loss of reactive power compensation technology 1N power distribution system and the electrical automation, improve the utilization rate, and realize the control of the voltage amplitude in the system network, voltage stability of power distribution system, has carried on the system analysis to reduce failure of the harmonic current to the power supply system and other functions. And the paper in-depth study on the application of reactive power compensation technology in electrical automation from the reactive compensation technology, substation and distribution line reactive power compensation, power users of reactive power compensation and other aspects.
基金Project (No. 50477033) supported by the National Nature ScienceFoundation of China
文摘Under unbalanced source voltage supply, considerable output second harmonics and input low-order harmonics in 3-phase PWM current-source converters (PWM-CSC) are generated. This paper proposes a new deadbeat controller based on compensation for unbalanced source voltage and current. With the proposed scheme, the second harmonics of the output current are eliminated and low-order harmonics of the source current are reduced effectively. Simulation and experimental results con- firmed the feasibility of the proposed method.
文摘Both winter DJF （December, January, February） months and DJF season means long-term data series of 50 regulated rivers discharges rates and the NAO indices were analyzed for different spans. This study is dictated for： （1） detecting the exclusive impacts of the positive phases of NAO indices on rivers discharges rates by estimating the Linear Correlation Coefficient; （2） modeling the interrelations between the discharges rates and NAO indices by estimating the Linear Regression Models, both for manifesting the impact of the positive phase of NAO index; （3） estimating the Linear Trend Coefficient in the discharge series, for manifesting the contribution of the positive phase of NAO index. Discharge rates are mainly influenced by the two mechanisms： the positive phase of NAO index and the environmental conditions in specific catchments, that is where, the positive phase of the NAO index manifest its impact on the related rivers discharges and its contribution in the related configured trends. The discharges fluctuations patterns show some increase in the discharges values have been occurred in regions around the Northern Baltic Proper as well as in Southern Finland and Sweden. The rivers such as Lagan, Nissan, Helgean, Venta, Pamu, Porvoonjoki, Lapuanjoki, Oulujoki, Kyronjoki, Wisla, Eurajoki, Odra, Lielupe, Gota alv, Motala strom, Nykopingsan, Vuoksi, Kalajoki and Simojoki haven not linear discharges changes registered depending on the specificity of the environmental conditions at the catchments areas for those rivers. The positive phase of NAO index has a linear relation with impacted river discharge.
文摘This research describes an integrated multi-channel high accuracy current control LED （light emitting diode） driver with low dropout regulator implemented in a 0.35μm TSMC 2P4M CMOS process. With the new trend of backlighting applications for mobile electronics and portable devices requiring a smaller size, lower cost, lesser noise and accurate current control LED driver, it came up with the idea of integrating more than one design features within a single chip. The analysis of using a capacitor-less low dropout regulator to power the constant current source has been explored, with the implementation of wide range battery voltage of 3 V to 5 V. Possible load current variations were introduced and verified to output a fixed voltage of 2.8 V. A regulated cascode current mirror structure forms the multi-channel configuration string of LED＇s; the design ensures a current matching of less than 1% error and achieves a high accuracy current control of less than 1% error, regardless of the LED＇s forward voltage variation. Moreover, for high end portable device with multimedia applications, dimming frequency can be set to 10 MHz. In addition, a switching output is a better approach for managing LED＇s contrast and brightness adjustment as well as maximizing power consumption, ensuring longer life for driving string of LEDs.
文摘This paper deals with the operation and performance of VSC （voltage source converter） based HVDC （high voltage direct current） interconnecting two extremely weak AC networks, the experience of Caprivilink project. It is shown in the paper that the HVDC converter automatically provides the supreme voltage and frequency stabilizing function when a critical situation is detected, no matter the disturbances appeared in sending end or receiving end AC networks. This supreme voltage and frequency stabilizing function makes it possible to avoid the blackout even if all the generators are tripped under an extra-ordinary worst contingency. By plots of recorded transients, the paper will show how the eventual blackouts are avoided.
文摘DC regulated power has play a decisive role status in the modem enterprise production and family life. With the development of science and technology, all kinds of computer simulation technology is increasingly rising, the paper simulate and compare common DC regulated power with adjustable DC regulated power by Altium Designer software, intuitively demonstrates the stabilizing effect of the circuit, and introduces the characteristics of adjustable DC regulated power. Using AD13 software simulate and design DC stabilized power supply circuit, calculated the main parameters of the circuit, simulated and analyzed the circuit working simulation process and the working state of the circuit, it can visually verify the results of the theoretical analysis, and get relevant conclusions.
文摘The study of peristaltic flow of a Carreau fluid in a non-uniform tube under the con- sideration of long wavelength is presented. The flow is investigated in a wave frame of reference moving with velocity of the wave e. Numerical integration has been used to obtain the graphical results for pressure rise and frictional forces. The effects of various emerging parameters are investigated through graphs.
