A design for a Li-ion battery charger IC that can operate in a constant current-constant voltage （CC- CV） charge mode is proposed. In the CC-CV charge mode,the charger IC provides a constant charging current at the ...A design for a Li-ion battery charger IC that can operate in a constant current-constant voltage （CC- CV） charge mode is proposed. In the CC-CV charge mode,the charger IC provides a constant charging current at the beginning, and then the charging current begins to decrease before the battery voltage reaches its final value. After the battery voltage reaches its final value and remains constant,the charging current is further reduced. This approach prevents charging the battery with full current near its saturated voltage,which can cause heating. The novel design of the core of the charger IC realizes the proposed CC-CV charge mode. The chip was implemented in a CSMC 0.6μm CMOS mixed signal process. The experimental results verify the realization of the proposed CC- CV charge mode. The voltage of the battery after charging is 4. 1833V.展开更多
We study persistent currents in the double Aharonov-Bohm ring connected to two electron reservoirs by quantum waveguide theory. It is found that the persistent currents in the double Aharonov-Bohm ring depend .on the ...We study persistent currents in the double Aharonov-Bohm ring connected to two electron reservoirs by quantum waveguide theory. It is found that the persistent currents in the double Aharonov-Bohm ring depend .on the direction of the current flow from one reservoir to another. When the direction of the current flow reverses, tl2e persistent current in each ring of the double Aharonov-Bohm ring changes. If the two rings are of the same size, the persistent currents in the left and the right rings exchange at the reversal of the current flow direction.展开更多
With the development of devices for high performance, the circuit technologies have been also studied. One of the main streams concerns a soft switching technology to mitigate switching stress, leading to the reductio...With the development of devices for high performance, the circuit technologies have been also studied. One of the main streams concerns a soft switching technology to mitigate switching stress, leading to the reduction in switching losses or electro-magnetic noise. On the other hand, as a characterized orthodox technology＇, the existing chopper circuit is used for the electric vehicles, etc.. Such technologies have a tendency to go out of vogue as power supplies for such vehicles. However, as a boost chopper for the battery charger for an electric vehicle, those technologies become a main stream, where a bilateral function is required. With the foregoing in mind, the authors have devised and analyzed the bilateral chopper using the soft-switch technology, which could be applied to a battery charger for an electric vehicle or similar.展开更多
Activated carbon （AC） was fabricated by using phenolic resin as carbon source, silica gel as inorganic template, KOH as activator. The samples were analyzed by N2 adsorption, scanning electron microscopy （SEM）. Cy...Activated carbon （AC） was fabricated by using phenolic resin as carbon source, silica gel as inorganic template, KOH as activator. The samples were analyzed by N2 adsorption, scanning electron microscopy （SEM）. Cyclic voltammetry and galvanostatic charge-discharge were used to characterize the electrochemical performance of the samples. The results showed that the pore size was mainly in the range of 0.5 9.0 nm. Supercapacitors based on the sample AC-3 have low equivalent series resistanceb （ESR） and excellent power property.展开更多
Applications of electric vehicles need to build a large number of charging stations. The electric vehicle charging stations communicate with the grid. In V2G （vehicle to grid） mode, electric vehicles can be used as ...Applications of electric vehicles need to build a large number of charging stations. The electric vehicle charging stations communicate with the grid. In V2G （vehicle to grid） mode, electric vehicles can be used as energy storage units and transfer power to the grid. The electric vehicles charge at night to reduce the cost and the grid load, simultaneously to fill the valley. When grid load increases, electric vehicles＇ batteries discharge to the grid to improve the stability of the grid. As distributed storage units, electric vehicles are important components of the smart grid. In this paper, the three-phase PWM （pulse width modulation） rectifier used for smart charging and discharging system of electric vehicles are analyzed and designed. This paper includes the principle of PWM rectifier-inverter and direct current control strategy. Also, the SVPWM （space vector pulse width modulation） and system design of three-phase PWM rectifiers are analyzed. A 10 kW prototype is developed. Simulation and experiment results show that the three-phase PWM rectifiers reach the unit power factor. From the experimental results, PWM rectifier implements the sinusoidal grid current and achieves the unit power factor.展开更多
Activated carbon （AC） was fabricated by Coconut shell as carbon source, KOH as activator. Cyclic voltammetry and galvanostatic charge-discharge were used to characterize the electrochemical performance of the sample...Activated carbon （AC） was fabricated by Coconut shell as carbon source, KOH as activator. Cyclic voltammetry and galvanostatic charge-discharge were used to characterize the electrochemical performance of the samples. The results showed that： Supercapacitors based on the sample AC-3 have low Equivalent series resistanceb （ESR） and excellent power property.展开更多
文摘A design for a Li-ion battery charger IC that can operate in a constant current-constant voltage （CC- CV） charge mode is proposed. In the CC-CV charge mode,the charger IC provides a constant charging current at the beginning, and then the charging current begins to decrease before the battery voltage reaches its final value. After the battery voltage reaches its final value and remains constant,the charging current is further reduced. This approach prevents charging the battery with full current near its saturated voltage,which can cause heating. The novel design of the core of the charger IC realizes the proposed CC-CV charge mode. The chip was implemented in a CSMC 0.6μm CMOS mixed signal process. The experimental results verify the realization of the proposed CC- CV charge mode. The voltage of the battery after charging is 4. 1833V.
基金The project supported by National Natural Science Foundation of China under Grant No. 10347004
文摘We study persistent currents in the double Aharonov-Bohm ring connected to two electron reservoirs by quantum waveguide theory. It is found that the persistent currents in the double Aharonov-Bohm ring depend .on the direction of the current flow from one reservoir to another. When the direction of the current flow reverses, tl2e persistent current in each ring of the double Aharonov-Bohm ring changes. If the two rings are of the same size, the persistent currents in the left and the right rings exchange at the reversal of the current flow direction.
文摘With the development of devices for high performance, the circuit technologies have been also studied. One of the main streams concerns a soft switching technology to mitigate switching stress, leading to the reduction in switching losses or electro-magnetic noise. On the other hand, as a characterized orthodox technology＇, the existing chopper circuit is used for the electric vehicles, etc.. Such technologies have a tendency to go out of vogue as power supplies for such vehicles. However, as a boost chopper for the battery charger for an electric vehicle, those technologies become a main stream, where a bilateral function is required. With the foregoing in mind, the authors have devised and analyzed the bilateral chopper using the soft-switch technology, which could be applied to a battery charger for an electric vehicle or similar.
文摘Activated carbon （AC） was fabricated by using phenolic resin as carbon source, silica gel as inorganic template, KOH as activator. The samples were analyzed by N2 adsorption, scanning electron microscopy （SEM）. Cyclic voltammetry and galvanostatic charge-discharge were used to characterize the electrochemical performance of the samples. The results showed that the pore size was mainly in the range of 0.5 9.0 nm. Supercapacitors based on the sample AC-3 have low equivalent series resistanceb （ESR） and excellent power property.
文摘Applications of electric vehicles need to build a large number of charging stations. The electric vehicle charging stations communicate with the grid. In V2G （vehicle to grid） mode, electric vehicles can be used as energy storage units and transfer power to the grid. The electric vehicles charge at night to reduce the cost and the grid load, simultaneously to fill the valley. When grid load increases, electric vehicles＇ batteries discharge to the grid to improve the stability of the grid. As distributed storage units, electric vehicles are important components of the smart grid. In this paper, the three-phase PWM （pulse width modulation） rectifier used for smart charging and discharging system of electric vehicles are analyzed and designed. This paper includes the principle of PWM rectifier-inverter and direct current control strategy. Also, the SVPWM （space vector pulse width modulation） and system design of three-phase PWM rectifiers are analyzed. A 10 kW prototype is developed. Simulation and experiment results show that the three-phase PWM rectifiers reach the unit power factor. From the experimental results, PWM rectifier implements the sinusoidal grid current and achieves the unit power factor.
文摘Activated carbon （AC） was fabricated by Coconut shell as carbon source, KOH as activator. Cyclic voltammetry and galvanostatic charge-discharge were used to characterize the electrochemical performance of the samples. The results showed that： Supercapacitors based on the sample AC-3 have low Equivalent series resistanceb （ESR） and excellent power property.
