Based on the analysis of ultracapacitors efficiency and vehicle driving character, three conditions restricting the ultracapacitors charge/discharge time are derived. The study focuses on ultracapacitors specific desi...Based on the analysis of ultracapacitors efficiency and vehicle driving character, three conditions restricting the ultracapacitors charge/discharge time are derived. The study focuses on ultracapacitors specific design rules decided by charge/discharge time and how to integrate with battery packs and converter through ultracapacitors＇voltage and current double regulators. Through BFC6100-EV electric bus test, it is shown that the proposed method and control strategy are feasible and the system can effectively improve the bus dynamic performance and ability to receive braking energy effectively.展开更多
A power system with proton exchange membrane fuel cells (PEMFC) was designed for thermal underwater glider.Heat generated by PEMFC is used as the propulsion power of the glider,and the electricity is used in the contr...A power system with proton exchange membrane fuel cells (PEMFC) was designed for thermal underwater glider.Heat generated by PEMFC is used as the propulsion power of the glider,and the electricity is used in the control and sensor system.An electric energy storage system (ESS) is required which possesses high power density with good cycle life.Ultracapacitors which exhibit high power density and cycle life are considered as energy storage devices.Simulations based on a specific voyage condition indicate that ESS with ultracapacitors has positive effects on reducing the output power demand of PEMFC and lightening the power system.Experimental results show that the state of charge (SOC) is related to the capacitance and resistance in ultracapacitor ESS.展开更多
The large variability in wind output power can adversely impact local loads that are sensitive to poor power quality. To mitigate large swings in power, the wind turbine output power can be conditioned by using a smal...The large variability in wind output power can adversely impact local loads that are sensitive to poor power quality. To mitigate large swings in power, the wind turbine output power can be conditioned by using a small energy buffer. A power conditioner is developed to smooth the wind power output by utilizing the energy of an electrochemical capacitor, or ultracapacitor. The conditioner is based on a single phase voltage source inverter connected between the grid inter-connection point and the ultracapacitor. The VSI shunt inverter injects or absorbs active power from the line to smooth the wind power output by utilizing the short term storage capabilities of the ultracapacitor. The ultracapacitor is connected to the DC link through a bidirectional DC-DC converter. The bidirectional DC-DC converter and VSI are constructed and field tested on a Skystream 3.7 wind turbine installed at the Missouri University of Science & Technology.展开更多
文摘Based on the analysis of ultracapacitors efficiency and vehicle driving character, three conditions restricting the ultracapacitors charge/discharge time are derived. The study focuses on ultracapacitors specific design rules decided by charge/discharge time and how to integrate with battery packs and converter through ultracapacitors＇voltage and current double regulators. Through BFC6100-EV electric bus test, it is shown that the proposed method and control strategy are feasible and the system can effectively improve the bus dynamic performance and ability to receive braking energy effectively.
基金Supported by the State Key Program of National Natural Science Foundation of China (No. 50835006)Science & Technology Support Planning Foundation of Tianjin (No. 09ZCKFGX03000)
文摘A power system with proton exchange membrane fuel cells (PEMFC) was designed for thermal underwater glider.Heat generated by PEMFC is used as the propulsion power of the glider,and the electricity is used in the control and sensor system.An electric energy storage system (ESS) is required which possesses high power density with good cycle life.Ultracapacitors which exhibit high power density and cycle life are considered as energy storage devices.Simulations based on a specific voyage condition indicate that ESS with ultracapacitors has positive effects on reducing the output power demand of PEMFC and lightening the power system.Experimental results show that the state of charge (SOC) is related to the capacitance and resistance in ultracapacitor ESS.
文摘The large variability in wind output power can adversely impact local loads that are sensitive to poor power quality. To mitigate large swings in power, the wind turbine output power can be conditioned by using a small energy buffer. A power conditioner is developed to smooth the wind power output by utilizing the energy of an electrochemical capacitor, or ultracapacitor. The conditioner is based on a single phase voltage source inverter connected between the grid inter-connection point and the ultracapacitor. The VSI shunt inverter injects or absorbs active power from the line to smooth the wind power output by utilizing the short term storage capabilities of the ultracapacitor. The ultracapacitor is connected to the DC link through a bidirectional DC-DC converter. The bidirectional DC-DC converter and VSI are constructed and field tested on a Skystream 3.7 wind turbine installed at the Missouri University of Science & Technology.
