The Experts below are selected from a list of 168 Experts worldwide ranked by ideXlab platform

Winghung Ki - One of the best experts on this subject based on the ideXlab platform.

  • the design of a micro Power Management System for applications using photovoltaic cells with the maximum output Power control
    IEEE Transactions on Very Large Scale Integration Systems, 2009
    Co-Authors: Hui Shao, Chiying Tsui, Winghung Ki
    Abstract:

    An inductor-less on-chip micro Power Management System for light energy harvesting applications is presented. We target at wide variety of applications that operate at different lighting environments ranging from strong sunlight to dim indoor lighting where the output voltage from the photovoltaic cells is low. A step-up charge pump is used to directly operate the circuit or to charge a rechargeable battery. The Power Management System operation is discussed and the control strategy for transferring the maximum output Power from the Power System is presented. Low Power circuit design is proposed for the implementation of the System maximum output Power control. The System was implemented using a 0.35-mum CMOS process. The chip was fabricated and measurements were conducted for different lighting conditions to demonstrate the System operation and verify the control strategy.

  • a micro Power Management System and maximum output Power control for solar energy harvesting applications
    International Symposium on Low Power Electronics and Design, 2007
    Co-Authors: Hui Shao, Chiying Tsui, Winghung Ki
    Abstract:

    A micro Power Management System is presented for solar energy harvesting applications. An inductor-less solution is proposed which facilitates on-chip integration of the System. We target at applications working in different lighting environments ranging from strong sunlight to dim indoor lighting where the output voltage from the photovoltaic (PV) cells is low. A charge pump is used to step the PV voltage up to charge a battery or directly operate the circuit. The Power Management System behavior is theoretically analyzed and the control strategy is derived to transfer maximum Power from the PV cells to the battery or the circuit. Circuit design and low Power techniques for the maximum output Power control are proposed for the System. The System was implemented using 0.35μm CMOS process. With the measured PV cells output characteristics, HSPICE simulations for the Power Management System were carried out to verify the control strategy and to demonstrate the System operation.

Hui Shao - One of the best experts on this subject based on the ideXlab platform.

  • the design of a micro Power Management System for applications using photovoltaic cells with the maximum output Power control
    IEEE Transactions on Very Large Scale Integration Systems, 2009
    Co-Authors: Hui Shao, Chiying Tsui, Winghung Ki
    Abstract:

    An inductor-less on-chip micro Power Management System for light energy harvesting applications is presented. We target at wide variety of applications that operate at different lighting environments ranging from strong sunlight to dim indoor lighting where the output voltage from the photovoltaic cells is low. A step-up charge pump is used to directly operate the circuit or to charge a rechargeable battery. The Power Management System operation is discussed and the control strategy for transferring the maximum output Power from the Power System is presented. Low Power circuit design is proposed for the implementation of the System maximum output Power control. The System was implemented using a 0.35-mum CMOS process. The chip was fabricated and measurements were conducted for different lighting conditions to demonstrate the System operation and verify the control strategy.

  • a micro Power Management System and maximum output Power control for solar energy harvesting applications
    International Symposium on Low Power Electronics and Design, 2007
    Co-Authors: Hui Shao, Chiying Tsui, Winghung Ki
    Abstract:

    A micro Power Management System is presented for solar energy harvesting applications. An inductor-less solution is proposed which facilitates on-chip integration of the System. We target at applications working in different lighting environments ranging from strong sunlight to dim indoor lighting where the output voltage from the photovoltaic (PV) cells is low. A charge pump is used to step the PV voltage up to charge a battery or directly operate the circuit. The Power Management System behavior is theoretically analyzed and the control strategy is derived to transfer maximum Power from the PV cells to the battery or the circuit. Circuit design and low Power techniques for the maximum output Power control are proposed for the System. The System was implemented using 0.35μm CMOS process. With the measured PV cells output characteristics, HSPICE simulations for the Power Management System were carried out to verify the control strategy and to demonstrate the System operation.

Sejin Kwon - One of the best experts on this subject based on the ideXlab platform.

  • active Power Management System for an unmanned aerial vehicle Powered by solar cells a fuel cell and batteries
    IEEE Transactions on Aerospace and Electronic Systems, 2014
    Co-Authors: Bohwa Lee, Sejin Kwon, Poomin Park, Keunbae Kim
    Abstract:

    200W class, low-speed, long-endurance unmanned aerial vehicle (UAV) that employs solar cells, a fuel cell, and a battery pack as its Power sources is considered. This study applies an active Power Management method that directs each individual source to generate the appropriate Power, depending on the Power supply and demand, instead of the passive method in which the Power sources irresponsibly generate Power, depending on their characteristics. The Power Management System (PMS) under active Management determines the Power output from each source. The flight test of the UAV with a PMS onboard is conducted for 3.8 h. The active PMS verifies its own feasibility as it successfully keeps the Power sources within their proper operational bounds and maintains a target state-of-charge of 45%, while responding to the various conditions associated with the Power required. In addition, through a comparison of flight test results with a Power simulation of the passive method, the usefulness, advantages, and disadvantages of an active Power Management method over a passive method are investigated.

  • fuel cell System with sodium borohydride as hydrogen source for unmanned aerial vehicles
    Journal of Power Sources, 2011
    Co-Authors: Sejin Kwon
    Abstract:

    Abstract In this study, we design and fabricate a fuel cell System for application as a Power source in unmanned aerial vehicles (UAVs). The fuel cell System consists of a fuel cell stack, hydrogen generator, and hybrid Power Management System. PEMFC stack with an output Power of 100 W is prepared and tested to decide the efficient operating conditions; the stack must be operated in the dead-end mode with purge in order to ensure prolonged stack performance. A hydrogen generator is fabricated to supply gaseous hydrogen to the stack. Sodium borohydride (NaBH 4 ) is used as the hydrogen source in the present study. Co/Al 2 O 3 catalyst is prepared for the hydrolysis of the alkaline NaBH 4 solution at room temperature. The fabricated Co catalyst is comparable to the Ru catalyst. The UAV consumes more Power in the takeoff mode than in the cruising mode. A hybrid Power Management System using an auxiliary battery is developed and evaluated for efficient energy Management. Hybrid Power from both the fuel cell and battery Powers takeoff and turning flight operations, while the fuel cell supplies steady Power during the cruising flight. The capabilities of the fuel-cell UAVs for long endurance flights are validated by successful flight tests.

Chiying Tsui - One of the best experts on this subject based on the ideXlab platform.

  • the design of a micro Power Management System for applications using photovoltaic cells with the maximum output Power control
    IEEE Transactions on Very Large Scale Integration Systems, 2009
    Co-Authors: Hui Shao, Chiying Tsui, Winghung Ki
    Abstract:

    An inductor-less on-chip micro Power Management System for light energy harvesting applications is presented. We target at wide variety of applications that operate at different lighting environments ranging from strong sunlight to dim indoor lighting where the output voltage from the photovoltaic cells is low. A step-up charge pump is used to directly operate the circuit or to charge a rechargeable battery. The Power Management System operation is discussed and the control strategy for transferring the maximum output Power from the Power System is presented. Low Power circuit design is proposed for the implementation of the System maximum output Power control. The System was implemented using a 0.35-mum CMOS process. The chip was fabricated and measurements were conducted for different lighting conditions to demonstrate the System operation and verify the control strategy.

  • a micro Power Management System and maximum output Power control for solar energy harvesting applications
    International Symposium on Low Power Electronics and Design, 2007
    Co-Authors: Hui Shao, Chiying Tsui, Winghung Ki
    Abstract:

    A micro Power Management System is presented for solar energy harvesting applications. An inductor-less solution is proposed which facilitates on-chip integration of the System. We target at applications working in different lighting environments ranging from strong sunlight to dim indoor lighting where the output voltage from the photovoltaic (PV) cells is low. A charge pump is used to step the PV voltage up to charge a battery or directly operate the circuit. The Power Management System behavior is theoretically analyzed and the control strategy is derived to transfer maximum Power from the PV cells to the battery or the circuit. Circuit design and low Power techniques for the maximum output Power control are proposed for the System. The System was implemented using 0.35μm CMOS process. With the measured PV cells output characteristics, HSPICE simulations for the Power Management System were carried out to verify the control strategy and to demonstrate the System operation.

Zbigniew Lewandowski - One of the best experts on this subject based on the ideXlab platform.

  • energy harvesting with microbial fuel cell and Power Management System
    IEEE Transactions on Power Electronics, 2011
    Co-Authors: Andrew Meehan, Zbigniew Lewandowski
    Abstract:

    This paper presents a System that can harvest energy in the water and use the harvested energy to Power electronic devices deployed in the water. The System consists of a microbial fuel cell (MFC) and a Power Management System. The MFC uses electrochemical reactions and bacteria that exist in the water to harvest energy and generate electricity. The Power Management System consisting of a charge pump, a super capacitor, two solid-state switches, and a boost converter accumulates the energy harvested by the MFC, stores the energy in the super capacitor, and bursts Power to the load. The Power Management System also boosts the voltage of the MFC to a sufficient level for the electronic devices. The presented energy-harvesting System is self-Powered, sustainable, environment friendly, and maintenance-free. The System has been tested and proven through experimental work.