Power balance control and voltage conditioning for fuel cell converter with multiple sources

Fuel Cells and Their Applications in Energy Systems

“…For a fuel cell system with multiple sources, especially with an added battery pack to help stabilize the fuel cell output voltage, additional power management converters are needed. In electric vehicles where cost is very sensitive, the fuel cell is normally stacked at a higher voltage level that can directly power the load, with an added battery-powered DC-DC converter that must be bi-directional as shown in Figure 9.11a and Figure 9.11b [65,[69][70][71][72][73][74]. Depending on system requirements, the added battery and associated bi-directional DC-DC converter can be used as an energy buffer to serve as power management for a stack with a significantly lower power rating for cost reduction.…”

“…With a large difference in voltage scale between input and output, the DC-DC converter circuit in [73] adopts an isolation transformer that changes the voltage ratio to allow switching devices rated according to their respected voltage levels. In [74], however, with a similar system architecture and similar voltage scale between battery and fuel cell, non-isolated circuit topologies are adopted. In addition, the system in [74] has a load voltage much higher than that of the fuel cell and battery, so two converters for both fuel cell and battery are needed to match the DC bus voltage, as shown in Figure 9.11b.…”

“…In [74], however, with a similar system architecture and similar voltage scale between battery and fuel cell, non-isolated circuit topologies are adopted. In addition, the system in [74] has a load voltage much higher than that of the fuel cell and battery, so two converters for both fuel cell and battery are needed to match the DC bus voltage, as shown in Figure 9.11b.…”

Simple and optimized fuel cell system for low voltage high current applications

“…One of the promising renewable energy sources is fuel cell generator that converts the chemical energy of gaseous fuel directly into electric energy [2,3]. By direct energy conversion, fuel cells enable higher efficiency, which makes them a promising "clean power" solution for low power as well as high power applications [4]. There are many types of the fuel cells characterized by used electrolyte.…”