The effects of the cell parameter and chemical composition on the surface charge properties of five kinds of different colour montmorillonites were studied. The results indicate that the surface isoelectric point（IEP...The effects of the cell parameter and chemical composition on the surface charge properties of five kinds of different colour montmorillonites were studied. The results indicate that the surface isoelectric point（IEP） of the montmorillonite shows positive correlation with the mass fractions of Fe203 and K20, but it has little relation to the mass fractions of other chemical compositions. At around pH=6.8, the surface zeta potential of the montmorillonite shows the negative relationship with the mass fractions of Fe203 and MgO, but it does not linearly correlate to the mass fractions of other chemical compositions. Cell parameter（bo） of the montmorillonite expresses negative linear relationship with mass fractions of K2O and Na2O, so does cosinβ with mass fractions of SlOE and Fe2O3. And there is no specific relationship between bo and IEP of different montmorillonites, but there is positive correlation between cosinβ and IEP of different montmorillonite samples.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
基金Project(2005CB623701) supported by the Major State Basic Research Development Program of China
文摘The effects of the cell parameter and chemical composition on the surface charge properties of five kinds of different colour montmorillonites were studied. The results indicate that the surface isoelectric point（IEP） of the montmorillonite shows positive correlation with the mass fractions of Fe203 and K20, but it has little relation to the mass fractions of other chemical compositions. At around pH=6.8, the surface zeta potential of the montmorillonite shows the negative relationship with the mass fractions of Fe203 and MgO, but it does not linearly correlate to the mass fractions of other chemical compositions. Cell parameter（bo） of the montmorillonite expresses negative linear relationship with mass fractions of K2O and Na2O, so does cosinβ with mass fractions of SlOE and Fe2O3. And there is no specific relationship between bo and IEP of different montmorillonites, but there is positive correlation between cosinβ and IEP of different montmorillonite samples.
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.
