Experimental Study on a Passive Fuel Cell/Battery Hybrid Power System

Abstract

A laboratory-scale passive hybrid power system for transportation applications is constructed and tested in this study. The hybrid power system consists of a fuel cell stack connected with a diode, a lithium-ion battery pack connected with a DC/DC power converter and another diode. The power converter is employed to regulate the output voltage of the battery pack. The dynamic responses of current and voltage of the stack to the start-up and acceleration of the load are experimentally investigated at two different selected output voltages of the DC/DC converter in the battery line. The power sharing of each power source and efficiency are also analyzed and discussed. Experimental results show that the battery can compensate for the shortage of supplied power for the load demand during the start-up and acceleration. The lowest operating voltage of the fuel cell stack is limited by the regulated output voltage of the DC/DC converter. The major power loss in the hybrid power system is attributed to the diodes. The power train efficiency can be improved by lowering the ratio of forward voltage drop of the diode to the operating voltage of the fuel cell stack.

An Energy Management System of a Fuel Cell/Battery Hybrid Boat

“…The energy management strategy for different power sources has great effect in influencing the fuel economy, dynamic performance and service life of power sources [22][23][24]. A states-based EMS is proposed in [22], in which the battery is connected to the DC bus by a bidirectional DC/DC convertor.…”

A Low-Cost High-Performance Interleaved Inductor-Coupled Boost Converter for Fuel Cells

“…So far, fuel cells, solar energy, and wind power stand as examples of the most successfully developed renewable energy sources. Yet fuel cells have the disadvantage of providing a low output voltage, and are unable to operate in parallel with other types of energy sources [1]. Furthermore, the output voltage provided by a fuel cell is found to vary with its load, according to which a power conditioner is required to boost the output voltage to a specified level for a DC linked load [2][3][4][5][6][7].…”

Online Energy Management of City Cars with Multi-Objective Linear Parameter-Varying L2-Gain Control

“…A smaller EE-index γ2 means that heat generation from mechanical damper and electric resistor is less in transience per distance. The QM-variable 1 z and EE-variable 2 z include the motor voltage u as an entry to protect both objectives from being achieved by cheap control, whereby to keep the motor voltage within a practical range in real operations.…”

“…(viii) 1 γ 0  is the performance index of QM, when the closed-loop 2 L -gain from the general disturbance q to the QM variable 1 z is set to one:…”

“…For example, lithium-ion batteries, fuel cells [1], high-capacity ultracapacitors, and ultrahigh-speed flywheels are too costly, and lead-acid batteries are too heavy. Therefore, it has become important for the industry to manage batteries to reduce consumption of electric energy.…”